Hyperspectral Imaging: Tomorrow's Tool for Mil Satellites

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Hyperspectral Imaging: Tomorrow's Tool for Mil Satellites

Post by Ved »

I feel that Indian space effort in the area of IMINT is well poised to enter the new dimension of Hyperspectral Imaging, which, I think, would revolutionise a great many things like the old concepts of camouflage, for example. I have put some of my thoughts down below. Comment?

INTRODUCTION

1. Today, the Indian military have access to surveillance facilities which are a major step ahead of those available a few years ago; however, our capabilities are still not commensurate with the state-of-the-art in cutting edge military operations and intelligence gathering, even considering our late as well as modest entry into the space arena. The introduction of high-resolution commercial imagery and advances in spectral analysis has greatly expanded the military’s use of commercial imagery.

2. Three limiting factors which affect optical surveillance are cloud cover, darkness and camouflage; the use of Hyper Spectral Imaging (HSI) and Synthetic Aperture Radar (SAR) would circumvent these limitations.

3. There are many applications where the combination (‘combo’) of HSI as well as SAR from a satellite platform could enhance the execution of various military functions, ranging from making it possible to accurately ‘guesstimate’ the payload from analyzing the plume of a rocket; to obtain real-time Battle Damage Assessment (BDA) after a strike mission; detecting and pinpointing an explosion involving an aircraft, like a crash situation; spotting enemy radars SAGW units or other formations in dense camouflage, or detecting and processing, in real time, data of reheat-assisted takeoffs from many airfields.

4. Perhaps as a result of riding piggy-back on the driving force of civilian applications of space technology till comparatively recently, the tools available to the Indian military have largely, hitherto, restricted themselves to the visible wavelengths and the more traditional forms of image analysis. While today’s possibilities in the area of visible imagery are considerable (the latest in the Keyhole series of satellites with resolutions in the order of 2.5 cms, or even less, spring to mind), imagery using visible wavelengths is only one of a number of options, and suffers from a number of serious limitations like clouds and darkness. The Defence Intelligence Agency (DIA) has, recently, articulated the requirements and expectations of the Services through a Space Vision document, the first of its kind, which is under consideration by various agencies including ISRO. Beyond this document, however, is a need to evolve specific requirements; the need for a payload exploiting HSI and SAR (either individually or in ‘combo’ vehicle) is one such requirement. I feel that optical imagery (meaning human analysis of optical pictures) is on the way out, and the new technology consists of HSI platforms (recently launched by the US, and hitherto undeveloped by India) augmented by SAR (under development).

5. India has proved herself capable of pioneering results even in a comparatively new area like space technology, indigenously fabricating comparatively advanced components, sometimes to the surprise of other more advanced powers! There is no reason, therefore, to shy away from a concept just because it has not been attempted (or has been rejected) by other more experienced powers; neither is there a reason to accept limits and barriers encountered by others when there appears to be a reasonable chance of overcoming the same through indigenous effort.

Hyperspectral Imaging

6. Hyperspectral imaging, also known as imaging spectroscopy, is on the way to becoming a key element in remote sensing. It is a type of multispectral imaging that records many tens of bands of imagery at very narrow bandwidths. In hyperspectral imaging, each pixel of the image records a wavelength. In addition to two spatial dimensions, the hyperspectral image contains a third dimension: radiant intensity. Measuring the energy that is reflected (or emitted) by targets over a variety of different wavelengths results in a spectral response for that object. By comparing the response patterns of different features we may be able to distinguish between them, where we might not be able to, if we only compared them at one wavelength. For example, water and vegetation may reflect somewhat similarly in the visible wavelengths but are almost always separable in the infrared.
7. All significant military structures, machines or devices have well known quantities of specific elements in their composition; thus, combat aircraft, for example, have a significant element of aluminum and titanium alloys, certain plastics and composite materials in their construction. Hyperspectral imaging involves acquiring and analyzing images simultaneously at multiple electromagnetic wavelengths. The wavelength information can be interpreted as spectral "signatures" of materials on the ground, and thus analysts can identify them remotely . Consider: if the chemical nature and hence identity of each component of the spectral image were to be instantly analysed, it would be possible to classify the source of such radiations. Based on the deductions of such an analysis, automated sequences could be triggered. Static targets like camouflaged or buried structures can also be detected by hyperspectral sensors on spaceborne platforms, which promise to significantly improve surveillance, target identification, terrain mapping and visualization capabilities for both land and sea operations.

8. Another significant advantage hyperspectral analysis has over normal spectroscopic analysis is the degree of intelligence which can be gleaned from even ‘bad’ spatial resolutions. Hyperspectral systems can potentially identify an object even if the image has only a few (or even one) picture elements (or pixels) covering the object. For normal imaging systems, this would be seen only as a blob in the image with insufficient spatial resolution to identify the object. Spectral analysis of each pixel provides additional information about the materials in the pixel. For hyperspectral systems, if the blob has a unique spectral signature, the analyst can identify it by this signature.

9. Like multispectral or optical imagery, HSI also requires the target to be illuminated by a light source; however, the angle of the light is not as critical in the case of HSI as in other cases, as analysis of the imagery would not be based on the visual appearance as seen by human analysts. In effect, this implies that the temporal window available for HSI operations would be very much more enlarged, with obviously greater flexibility of usage. Certain satellites such as the Defence Meteorological Satellite Programme are able to tune the amplifiers of their scanning devices so as to operate at night under very low illumination conditions. However, the technology in this area being relatively new, the integration of this facility with military applications has yet to materialize.
The Warfighter-1 Programme

10. The first such programme ever, the Warfighter-1 program is an advanced technology demonstration program that will provide hyperspectral imagery and related technology and services as a part of the ORBView-4 (by Orbital Imaging Corp (Orblmage)) high-resolution imaging satellite. Initially, the plan was to use ORBView-3, and OrbImage's OrbView-4 (OV-4) is being modified to incorporate the Warfighter-1 (WF-1) hyperspectral sensor. The program will also include the evaluation and validation of hyperspectral technologies, development of a mobile ground station, related image processing algorithms and software for assessment of tactical utility for military applications.
11. To a hyperspectral camera, neither the leaves on a tree or a decoy look anything like camouflage netting or paint, or a real vehicle or aircraft, respectively, because they are made from different materials. In fact, hyperspectral imaging can detect the subtle differences between two types of similarly colored paint - one applied to a friendly military vehicle and the other used by the enemy. That very well could spell the end of camouflage as we know it, as camouflage paint will no longer keep an enemy hidden. In the short wave infrared portion of the spectrum, many paints are transparent, so these bands can be analysed to look at materials beneath the paint. A typical hyperspectral image, after processing, looks like an ordinary picture except that special colors can be added to identify objects of interest. For example, all the non-armored material in a suspected tank harbor can be made to look red, clearly exposing decoys and camouflage. With a resolution of 8 meters, Warfighter 1 will be able to spot large targets of military interest.

12. Some specific attributes of hyperspectral imagery described below could be exploited for military operations.

Detection of Missile Launches

13. Relevance. Analyses of missile plumes would permit an accurate assessment of their trajectory, nature of rocket engine and hence even the nature of the payload. Such a capability would provide a realistic early warning of hostile missile launches, thereby enhancing the range and quality of response, which would largely depend on State policy. In the case of ballistic missiles, even assuming that there would be no deviation from the present ‘ No First Use’ policy, such early warning would enable better and more credible response. The application of such a facility would not be confined to the nuclear context alone; the Ghauri and Shaheen, it must be remembered, also follow a ballistic path, like the Prithvi series, and so early warning of these weapons would be relevant in a conventional conflict as well. Admittedly, hyperspectral analysis of the plume would not indicate whether the warhead were nuclear or conventional, a limitation we would have to live with for the foreseeable future!

Monitoring Aircraft Movements

14. The detection of high-flying aircraft is also an area which is being studied; the TEAL EMERALD project consists of detection of aircraft from space, including the determination and discrimination of the spectral signatures of ICBMs/SLBMs from strategic aircraft as observed from a space borne sensor. The current state-of-the-art looks at the detection of aircraft flying in the higher reaches of the atmosphere; however, the application is still in its infancy, and has obvious potential.

15. We can take our imagination further; after-burning combat aircraft routinely feature a long flame from the exhaust at the time of take-off. This flame is of the average temperature of 800-840º C, and, when compared to the ambient atmosphere, would stand out in stark contrast. Detection of a number of such flames within a given time period, for example, could well give early warning of an impending air strike. Accurate activity patterns from potentially hostile airfields could also be monitored in real time by satellite.

Detection of Air Crashes

16. Aircraft use a number of materials in their construction, materials which are typical to aviation structures. The detection of these elements by spectral analysis would provide instant warning in the event of crashes, especially when dealing with remote and inhospitable terrain as found in the Asian subcontinent. This, even in peacetime, would be a valuable feature and one which problem area which is currently being addressed.

Battle Damage Assessment (BDA)

17. Effective BDA could be carried out by employing the attributes of hyperspectral analysis. It would be possible to analyse images of the target which reveal recent moving of earth or evidence of damaged structures like broken masonry, runway craters etc, as well as similar evidence to interest the Army and Navy like freshly prepared minefields and underwater shore defenses.

Identification of Mobile Radars and SAGW Sites

18. When deployed, mobile radars and SAGW sites are dispersed and camouflaged, making them difficult to spot and target. Using HSI, such protection will be denied to these targets, the concept of optical or thermal camouflage being now rendered obsolete! During darkness or bad weather, SAR would immediately bring into sharp relief the existence of all metallic objects.

Spectroscopic Analysis of the Battlefield: the Concept of ‘Mission Space’

19. The knowledge of 'mission space', which would include specific details of geographic terrain, is a central premise for decision making in a tactical scenario. There are many applications of HSI which would enhance military operations; some of them have been listed at Appendix B, and all fall within the generic categories mentioned earlier in this document. A common view of the mission space is that it is based on a geospatial framework that includes imagery data, elevation data, and feature data. Geospatial information must therefore be an integral part of the overall defense information infrastructure. Spectral analysis would be an indispensable tool in such operations. Increasingly in the future, operational needs will be partially fulfilled by commercial satellites for both land and sea operations. The scope of surveillance would be immense; for example, even soil disturbance can be an indicator of changes such as those produced by foot, vehicles and buried mines, such changes being detected by physical characteristics of the soil like mineralogical composition, particle size, particle coating, lignin and cellulose content etc. Hyperspectral products (the term ‘product’ is one commonly used by PIs to denote a ‘scene’ of imagery which has been analysed and annotated by trained PIs) would consist of a change detection map that would locate areas which have been disturbed by military activities. This information would be merged with other data sources within a GIS system for intelligence / strategic planning. For land-sea operations, knowledge of near shore bathymetry would be critical for a variety of applications like landing beach assessment, input variables for various modeling algorithms (acoustic prediction, tide and surf forecasting, weapon systems), planning charts (command and control, mission planning, tactical decision aids) etc. These map layers could be integrated with other sources of information (i.e. topography, hydrology, roads, weather, radar) within a Geographical Information System (GIS), a common system which combines aspects of mapping, graphical displays and database management. The system will provide predictive information on the effects of terrain on military operations and will support decision making and planning of operations. Some general applications of HSI are listed at Appx A.

SYNTHETIC APERTURE RADAR

20. Unlike electro-optical systems, radar satellites can see through clouds, rain, and fog in order to detect targets on the ground or underground, and in or under the ocean. In addition, SAR satellites are extremely useful in tracking moving targets, and can be useful in satisfying military mapping requirements. Chinese engineers have been examining SAR satellites as a means to track enemy submarines in shallow waters.

21. One of the most significant aspects of SAR is the extremely strong echo which results from metallic targets, thus immediately negating the effect of camouflage or concealment measures. For example, the barbed-wire fence along the LOC, when viewed from an airborne SAR camera at 40,000 feet, appeared as a very prominent white line, even eclipsing adjacent objects of much larger physical dimensions or greater colour contrast in the visible spectrum. While the intensity of the return may even obscure the outline of the target it could still form the basis of accurate positioning; for example, the ‘fixing’ of coordinates for location of a mobile radar whose approximate position had been triangulated by means of ELINT.

22. Radar has special military value because, using the right wavelengths, this active system can "see through" clouds and can operate at night. The U.S's Lacrosse series consists of a SAR sensor mounted on a very large (reputed to be school bus sized) platform that ties to extended solar arrays. No Lacrosse/Vega images are available on an Internet Search suggesting the secretive and classified nature of this system. The current Lacrosse can probably achieve 1 meter or better resolution. Missions have included providing imagery for bomb damage assessments of the consequences of Navy Tomahawk missile attacks on Iraqi air defense installations in September 1996, monitoring Iraqi weapons storage sites and troop movements. Vega photographed the Shifa Pharmaceutical Plant in Sudan that was hit in the U.S. retaliatory strikes after the Embassy bombings in 1998. The TESAR (Tactical Enhanced SAR) program produces high resolution images like that of the most famed military building in the world - the Pentagon outside Washington. D.C. As an example of the capabilities of BDA by a satellite platform, Appx S shows the results of BDA by satellite following an air strike on a Serbian barracks during the Bosnian conflict.



BENEFITS OF A ‘COMBO’ PAYLOAD

23. Considering the benefits of both HSI and SAR, a combination (‘combo’) payload combining both facilities would yield the following payoffs:-

(a) Since HSI is not as demanding of light conditions as multispectral or normal optical imaging, a larger window of utilization would be available; assuming eight usable hours of daylight and a 100 min period per orbit, it would be possible to extract many more orbits per day during daylight hours than is currently possible with visual imagery satellites, where manual analysis in the visible wavelength demands a sun synchronous orbit aimed at close to noon over the target area.

(b) The satellite could be gainfully used during hours of darkness by employing the SAR sensor.

(c) As an aid to HSI would be the definition of form and outline, SAR would be able to provide an input in this area, which may be integrated with the HSI data by suitable software developed for the purpose.

(d) During daylight hours, both HSI and SAR could be used to augment each other; this may save the wastage which would occur in case of the target being obscured by heavy clouding.

24. Would a ‘combo’ payload be possible? There could be various aspects of size, weight or power consumption which could render the proposal prohibitively expensive or even unworkable. To adequately address this point the issue would need to be studied by ISRO. In the event that a ‘combo’ arrangement were not possible, separate satellites would need to be used for each payload; even so, the gains from each would be substantial and would be justifiable in their own rights.



Antenna Size

25. For the longer wavelengths beyond visible light, a significant problem could be that of antenna size. Astronomical radio telescopes have no constraints regarding antenna size, which could go into hundreds of meters; however, the same problem applied to a satellite, with the attendant complexities of stowage and subsequent deployment, could prove to be a taxing issue where the longer wavelengths are involved. One alternative could be an arrangement which unfolds in numerous sections to deploy as a large antenna (certain US projects are reported to feature plans for a 100m antenna ); whatever the chosen solution may be, at this stage of expertise the Indian space industry needs to prove itself capable of effectively addressing the problem, of which, in the author’s opinion, there is no doubt, as the requirements will be more in the area of innovation and mechanical dexterity rather than technology. However, this would require a concerted thrust in this area, which, again, would only come about only from a direction from a sufficiently high level.


DEPLOYMENT AND ORBITS

Timeliness

26. While the technology itself may permit such applications, associated measures required to ensure its effectiveness may considerably increase the total cost of the option. The relevance of the time factor in which the data is provided to the end-user is all-important, beyond which the data would cease to be of any value. In a typical air operation, for example, BDA would be required in order to assess the damage to the target, which would determine the need for follow-up attacks, perhaps the same day; in case this information were delayed beyond a certain point, the value of the data would cease to be relevant. Thus the timeliness of the delivery of remote-sensing data from the spacecraft to the user directly affects its utility. This delay could extend from days to weeks or more, and is a consequence of relatively long revisit time, relatively limited capabilities to look off to the side of the satellite’s ground track, and relatively low throughput for image-processing systems on the ground. Overcoming these limitations is expensive, both in equipment cost and personnel hours. Thus, there would be a need for a mechanism to prioritise various requirements, especially relevant in our context where the number and type of platforms are, as yet, restricted. Timeliness, therefore, justifies sufficient reason to invest in a significant effort to provide the means to convey the data from the satellite to the warfighter/operational planner within a timeframe which is of relevance to the end user; this could effect decisions affecting the number of satellites or types of orbits.

Timing of BDA Passes

27. There is no fixed response to the question of how soon after the strike BDA missions would be required, as it would depend on many factors such as whether the target were important enough to warrant a second strike if the first one didn’t have the desired effect, whether it were protected well enough to
make aircraft losses a good possibility, etc.

28. BDA missions in our context would, in the foreseeable future, probably continue to comprise dedicated manned aircraft augmented by UAVs for important targets. As a comparison, however, BDA during Gulf War II was rarely less than a couple of hours following the strike, frequently within the hour. It must be noted, however, that the US philosophy apparently mandates the launch of a constellation of satellites to cover specific operations. The schedule of the passes by US satellites were frequently within the hour, almost always within two to three hours.

29. In the Indian context, while the warfighter would probably like BDA as soon as he could get it, within minutes of the strike if possible, financial constraints would be unlikely to support such a luxury every time; however, the requirement for timely BDA would exist, nonetheless; a possible method to meet this demand is discussed subsequently.

Limited Constellations

30. Ideally, HSI and SAR sensors, if placed on a geostationary platform, would provide the optimum coverage in all areas; however, the state of the technology at the present time would be unlikely to support this requirement due to difficulties of both HSI and SAR applications to perform at orbital ranges exceeding circular or polar orbits. Such being the case, a number of maneuverable satellites would ensure that the specific requirements are met, while emergent demands could be catered for by vectoring the satellite as required. With such an arrangement, short term requirements of BDA, for example, could be met.


FUTURE DEVELOPMENTS

Micro - Satellites

31. The current emphasis in the satellite industry is on replacing large satellite platforms with one or more smaller satellites, built at lower costs, yet able to accomplish similar mission objectives. In this context, there is increasing interest in the potential capabilities and applications of so-called "micro-satellites" satellites of 10-100 kg. However it is recognized that such small satellites pose severe constraints on payload volume, mass and power. Thus, they would appear to be inappropriate for missions such as synthetic aperture radar (SAR) imaging, where payloads have significant size and power demands - specifically the large SAR antenna and high-power radar transmitter. The primary reason for the high transmit power requirement is that traditional SAR systems use backscatter, which is weak from most terrain types as most energy is scattered in the forward direction. Thus, if it were possible to gather this forward scattered element, then the transmit power requirements could drop significantly, potentially making it feasible for installation on a micro-satellite. This research is based on this principle of collecting to the forward scattered element - a novel method by which two micro-satellites 'fly' in a specific formation to accomplish a SAR imaging mission bi-statically. The transmitting satellite will be the master, with the receiver satellite slaved off it for synchronization. The satellites view a swath of 30x30 km, at a ground resolution of 30 m, from an altitude of 700 km. The constellation geometry proposed requires minimal orbit control resources, and allows for the resolution of the left-right ambiguity. The satellite design is based on the Surrey Satellite Technology, Ltd. enhanced micro- satellite, with a mass of 100 kg, and a standard volume of 1x1m base and a 0.6 m height.


State-of-the-Art as an Aiming Point

32. Operation Enduring Freedom, the US operation in Afghanistan post 9/11, may not have had much opposition as far as a battle goes, but was an effective demonstration of the state-of-the-art use of the space medium. To quote from a documented account……
‘Before the first soldier, sailor, airman, or Marine was placed in harm’s way — and well before the first unmanned aerial vehicle was deployed — we used satellites to scan hundreds of thousands of square miles of Afghanistan’s rugged terrain. This information gave us a feel for the terrain, for the weapons that potentially could be employed against us, and for an initial set of targets to be attacked with cruise missiles and high-altitude bombers. We used satellites to collect electronic and signals intelligence on the enemy. Satellites fed constant data about cloud cover and moisture into weather forecasting programs. Satellites with spectral imagers were used to detect changes in terrain features indicating potential use by the enemy. Satellites were also available to detect the infrared signature of a missile launch if the terrorists had possessed that capability. Satellites were our first “eyes on target” operating 24 hours a day, during day and night and in all weather. As the decision neared to deploy forces into theater, digital terrain data provided by satellites were used to develop 3-D images of terrain and streets and even to give military planners an idea of the view from a terrorist’s window. This proved to be a boon for pilots flying low-altitude missions through rugged mountains and for special operations forces carrying out covert raids... [/i]
33. The space requirements of the Indian military has, hitherto, been molded more by the dictates of civilian requirements, rather than military considerations. This has resulted in certain wavelengths being exploited only as far as required for civilian applications; the classic case is that of IR, where development has remained restricted to mainly agricultural, marine and geological functions of remote sensing. The development of the Synthetic Aperture Radar (SAR), as yet on an aircraft platform, is a welcome step; even so, the first space-borne application of SAR is not expected to be launched for at least the next two years.

34. Today, bodies like the Space Commission, organisationally under the Prime Minister do not contain any representation of the Services or the MOD. As major decisions regarding the utilization of space are invariably shaped at these forums, it is hardly surprising that military considerations were rarely, if ever, taken into account.


Hyper Spectral Imagery: Upsetting Old Paradigms

35. HSI will trash many old concepts and perceptions; like the X-Ray eyes of the legendary Superman of fiction, HSI will enable its users to look below layers of paint to see the nature of the structure below; to differentiate a wooden mock-up, however realistic, from the ‘real thing’; to spot locations of freshly laid minefields or beaches with booby-traps just by scanning the terrain, and that too, not after hours of painstaking effort by human PIs, but by almost immediate, colour coded computerized images. The possibilities presented by HSI go far beyond those presented by optical imagery.

36. Conventional optical imagery, for which the mechanism is matured, will continue to be of significance, but only till HSI becomes available. Another crucial aspect, SAR, is already under development. However, the time is ripe for the Services to look beyond conventional optical imagery and consider the wealth of information available through HSI and SAR. Development in the space area is as slow as in any other field, and gestation times are large. The Services have clearly articulated their concept of development in the years to come; there is a need to focus on the development of HSI, as the technology for tomorrow.


RECCOMMENDATION


37. As a logical follow-up of the Space Vision, the Services need to strongly project a need for the development of a crucial cutting edge technology, ie, Hyper Spectral Imaging (HSI), operating from either a ‘combo’ space vehicle incorporating an SAR sensor, or from a dedicated maneuverable satellite.


CONCLUSION

38. The utilization of space by the Indian military is still in its infancy; the significance of space being first recognised a little more than two decades ago, the requirements of the Services were first addressed by minor modifications to existing civilian applications. It is not surprising, therefore, that even today the Services remain largely confined to optical imagery, with the use of SAR yet to be operationalised. There is a need to move beyond optical imagery and focus on one of the cutting edge technologies today; spectral analysis through HSI promises a wide variety of revolutionary functions and benefits which would significantly enhance our IMINT capability.
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Post by Arun_S »

Ved: Why not make it as a BRM article?

OTOH am not sure there are enough people on forum to debate & critique on th efiner aspect of a techno/logical article, to be useful as seprate thread.
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Post by Ved »

Arun_S wrote:Ved: Why not make it as a BRM article?

OTOH am not sure there are enough people on forum to debate & critique on th efiner aspect of a techno/logical article, to be useful as seprate thread.
OK by me, youre the boss! How do I do it?
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Post by Arun_S »

Ved, I suggest to keep open this thread & wait from interest level from BRF'ites for commnets/critique/interest.

In any case why not research/embellish it and submit it to BRM editor(s) for publishing consideration.
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Post by ramana »

Ved have you looked at the sensor requirements from an Indian POV and not the US? Also the computing requirements to process the imagery? The paper looks like an effort at selling a concept. Could this gizmo look at snow bound areas and keep an eye? How about the oceans and find ship tracks/wakes?
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Post by dipesh.c »

This would be a really cool article. It's like thinking outside the box.
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Post by shiv »

Ved wrote:
Arun_S wrote:Ved: Why not make it as a BRM article?

OTOH am not sure there are enough people on forum to debate & critique on th efiner aspect of a techno/logical article, to be useful as seprate thread.
OK by me, youre the boss! How do I do it?
Oh we have had several threads that have become BRM articles. If the content is useful and informative enough as I believe this is - I think it should go on BRM on a more long term basis. the readership profile of BRF and BRM are different.

Let the thread be anyway.
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Post by Ved »

ramana wrote:Ved have you looked at the sensor requirements from an Indian POV and not the US? Also the computing requirements to process the imagery? The paper looks like an effort at selling a concept.
Your'e right - the concept is..... the Services are the users, who do not have the scientific expertise, but are, ultimately, the best judge of what is required. The article is an effort to crystallise their opinion in terms of effect, in terms of desired result. Once that is decided, the end-result would be suitably formulated and handed over to ISRO to translate into scientific fact. The issue is not so much as to how a particular effect can be achieved by HSI (the scientist's problem), but can the desired effect be achieved by HSI (the Service's problem).
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Post by Airavat »

HSI is also useful for:
Toxic) gas detection
Toxic gasses, gas leaks, and exhaust gasses can be examined from a distance using passive remote (hyper) spectral imaging techniques. Active techniques are also applied using LIDAR and DIAL systems. Many technologies improvements over the last decade in the field of electro-optics have lead to increased interest in the spectroscopic techniques for gas detection.
http://www.tno.nl/instit/fel/os/prg/the ... ctral.html


Ved,

What about the time and cost factor?
How much research (months/years) is needed and what sort of funds will make this system a reality?
What about cooperation with other countries?

Some images from FAS:http://www.fas.org/irp/imint/hyper.htm
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Post by Cybaru »

ramana wrote: Also the computing requirements to process the imagery?
Hmm, hardly a problem nowadays.. Large clusters designed to do such things are easy..

Ved,

How many such satellites would you need to provide data for it being useful for BDA. Won't you need instant data assestment so as to decide whether you want to remount an attack at the same point if the objective was not met ?

Nice write up .. pretty informative.. thanks..
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Post by Rudra »

ISRO ground processing centers already have the requisite experience with many type of image processing. ONGC also has a center somewhere that uses satimint to locate potential oil bearing areas I think. the knowhow to make inexpensive large server farms and the sw to run them is both commercially available and known to indian cos. so the ground end shouldnt be a problem.

I second the idea that it could be hewn into a BRM article.
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Post by NRao »

Very nice.

Contents are enough to scare the Pakis.
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Post by Ved »

[quote="cy_baru
Ved,

How many such satellites would you need to provide data for it being useful for BDA. Won't you need instant data assestment so as to decide whether you want to remount an attack at the same point if the objective was not met ?

Nice write up .. pretty informative.. thanks..[/quote]

Well, if we have 3-4 polar orbit manoeuverable platforms , it will be possible to bring in a satellite with approximately a day's notice,and keep one more or less on station till required (assuming the action won't last more than a month or two). This would probably give us the capability of providing BDA within a couple of hours, if not less.
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Post by Arun_S »

Polar orbit revisit frequency is typically 6 days, expending fuel for repositioning in war scenario will quickly exhaust the fuel, thus is taken as an extream measure rather than regular operation.

Thus there need be at least 6 Polar orbit assettes for ~6 to 12 average delivery time. And that requires set of sates for optical band and another set for Radar/SAR. Rememeber that Polar orbit based images are most useful when taken at the same time of the day for photo differentiation.

An alternate optical survillance approach would be use pair of 12 hour equitorial orbit (@ ~18,000Km hight) that would give enough side glance range for areas 3000Km from Indian borders. Optics improvement continues unabted. Europe is banking on it such that in the next 15 years they are planning GSO based optical survillance sats with 1 meter resolution.

Most cost effective scheame is to launch Multi-spectral sats that has Optical & SAR sensors (Op-SAR). A constellation of RISAT class sats is critical, and with second launch pad there is enough PSLV capacity to launch a set of 6 sats. GSLV-MKI/II can launch two OpSAR sats (weighing 1.5 tonne each) in a mission that would be more cost effective.
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Post by gashish »

Hi,
I agree with Rudra on our capabilities in ground processing technologies.
As an intern, I had a chance to work at National Centre for Radio-Astrophysics,TIFR,Pune http://www.ncra.tifr.res.in . The scientists @NCRA were studying pulsars,supernova remnants and other such fancy deep-space objects, while the engineers were working on cutting-edge tech in many areas like image and signal processing,synthesis imaging,radio interferometery,computing(the first time I saw PARAM..:), in fact CDAC is located near NCRA).
I'm guessing that the ground processing technologies that go in to enable radio astronomy would be similar to ones Ved is talking about(SAR) or at the least, fundamentals would be the same? ..or may be I'm totally on wrong track here...

(PS: Giant metrewave radio telescope of NCRA is biggest of its kind(operating around 1 meter wavelengths) in the world..pic of GMRT: http://www.isro.org/space_science/Facil ... etails.htm)

Ashish
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Post by Vick »

It seems that ISRO has already taken some steps in the multispectral imagery dept.
A couple of interesting links...

MOS on PRIRODA and IRS-P3

This is a very detailed info page on IRS-P3
The IRS-P3 Mission

Those crazy Germans :)
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Post by ramana »

Vick, Hyper-spectral is beyond multi-spectral. Its like a surface X-Ray compared to a color picture. Thats why Ved is proposing it.
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Post by Ved »

Arun_S wrote:expending fuel for repositioning in war scenario will quickly exhaust the fuel, thus is taken as an extream measure rather than regular operation...

Not so - without going into details, minor positional changes (ie, within 1000 odd kms) will not use up much gas. Remember, we will have notice - is there anything like a surprise attack (regarding declaration of hostilities) anymore?
Arun_S wrote:Rememeber that Polar orbit based images are most useful when taken at the same time of the day for photo differentiation..
For MSX, certainly - hence the sun synchronous orbit. But not with HSI, which I think I mentioned in the article.
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Post by Bade »

There really isnt much of a difference between multi-spectral and hyper-spectral sensors in terms of physics. The current crop of top of the line EOS (earth observing sensors) have 30 odd band info per pixel at 10nm resolution in bandwidth.

Hyperspectral imagers will sample perhaps more of the atmospherically transparent electromagnetic window. But can they do better than 10nm in resolution ?

The engineering challenge is in putting multiple detectors sampling the same geolocation at whatever resolution u want on a payload space (max 1 sq m or less, some fraction of fairing dimensions). Not to mention data throughput.
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Post by Vick »

ramana wrote:Vick, Hyper-spectral is beyond multi-spectral. Its like a surface X-Ray compared to a color picture. Thats why Ved is proposing it.
True, I was googling for hyperspectral stuff and found those pages on IRS sats. Figured that since ISRO is definitely into multi-spec stuff, it's only a matter of time before they delve into the hyper-spec stuff. From the other readings, ISRO is definitely in the direction of hyper-spec stuff. most likely will be tech demo'd in the next couple of IRS sats.
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Post by Singha »

can it detect underground structures like a ground penetrating radar on the surface can ? by structures I mean say a C3I center buried 10m below a airbase or munitions dump deep inside a mountain.

btw detecting presence of a.c by heating of concrete behind their former parking spots has been done for a long time. Bill Gunstons masterpiece "Spy planes and electronic intelligence aircraft" has actual imagery. I used to have it, a gift from my father but ^&^%%% lost it somewhere during a move or its still at home in india.

the whole salamander books series by bill gunston in the 1980s was superb. the spy planes book is still available used for a pittance from abebooks.com if any DOO/BWT want to try it.
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Post by Bade »

can it detect underground structures like a ground penetrating radar on the surface can ? by structures I mean say a C3I center buried 10m below a airbase or munitions dump deep inside a mountain.
Are there really any radiation that can penetrate 10m below ground . Dont think so. Most of the Hyperspectral imagers are passive devices in that they detect absorbed and emitted sunlight. Outside of water vapor bands u can see in the visible region. Microwave region penetrates cloud and currently sea surface temperatures are routinely measured at day and night. Thermal imagers (infra-red region) are useless with presence of clouds.

The only radiation/particle that can penetrate 10m and above are muons. So u need to have a muon tomography of your traget done from a payload in SSO to get that far below, I think.
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Post by SaiK »

http://www.darpa.mil/mto/solicitations/ ... tion1.html

The primary objective of the AFPA program is, therefore, to develop an electro-optical imaging sensor that benefits from both hyperspectral and forward looking infrared (FLIR) characteristics while avoiding the large mass of hyperspectral and the poor signal-to-clutter ratio (SCR) of FLIR. An infrared FPA is envisioned that employs an active filtering mechanism of some design in each pixel to provide spectral tuning and scene sampling with temporal and spatial simultaneity.

The intent of the AFPA program is to develop technology to demonstrate multispectral imaging (MSI) and possibly hyperspectral imaging (HSI) in a standard FLIR package. Currently, there are no imaging arrays that can be tuned on a pixel-by-pixel basis across the IR. This technology will enable staring FPAs that are capable of adaptively seeing through obscurants, imaging targets in diverse clutter, and performing precise chemical agent identification. Owing to its adaptivity, this technology will provide an essential sensing element to aided target recognition (ATR) systems.

..........

will meet the conflicting requirements for large area search coupled with the ability to detect and identify difficult and hidden targets, while staying within the processing volume and size available in small platforms.
...

A capability to detect information in multiple spectral bands will greatly facilitate target discrimination at the focal plane. ...Without a means of multi-spectral band discrimination, there exists significant risk that targets will be missed and threats to both people and vehicles will not be detected

..

future simultaneous multiwave

band (e.g. MWIR and LWIR) pixel level reconfigurability
...

integration of pixels into large format focal plane arrays..

high-performance electro-optical imaging sensor with the capability to exploit both the spectral and spatial content of a scene in order to achieve a high probability of detection with a low false alarm rate.
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Post by Arun_S »

Ved wrote:
Arun_S wrote:expending fuel for repositioning in war scenario will quickly exhaust the fuel, thus is taken as an extream measure rather than regular operation...

Not so - without going into details, minor positional changes (ie, within 1000 odd kms) will not use up much gas. Remember, we will have notice - is there anything like a surprise attack (regarding declaration of hostilities) anymore?
What we are talking is polar orbit not GSO correct? Irrespective, the sat will not stay at that spot for long, thus the problem doesnt go away, and there is limited fuel budget.

Ved wrote:
Arun_S wrote:Rememeber that Polar orbit based images are most useful when taken at the same time of the day for photo differentiation..
For MSX, certainly - hence the sun synchronous orbit. But not with HSI, which I think I mentioned in the article.
Yes but that huge source of additional data also poses a more formidable problem for Indian RAD-HARD IC technology, that of requiring huge on-board processing. [Assuming that the idea of ground based processing is not possible or useful]

One of the reason US mil sats are so huge and heavy [i.e. size of a big school bus] is because it has huge on-board computers and solar panels to power it.

IIRC Indian RADHARD chips (80486 class) are adquate for space mission and control, they are not heavy duty on computation, much less arranging them as arrey to serve as supercomputer in space.

JMT.
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Post by Cybaru »

Arun_S wrote:
IIRC Indian RADHARD chips (80486 class) are adquate for space mission and control, they are not heavy duty on comptation, much less arranging them as arrey to serve as super computer in space.

JMT.

I don't think, we should even try and add computational elements to our satellites. RADHARD solid state storage devices have become abundant and real cheap. The real complexity will still be getting enough bandwidth to download all the data. The prices are down to $10000 dollars for 200 GB worth of non volatile storage in a small form factor. This only promises to geat cheaper and larger.

Although doing computations in space solves the problem of downloading data as only processed/cooked data now needs to be downloaded. Any planned changes to the computational methods become difficult to implement if the compute methods are hard coded or hardware based.
The usual set of issues flaunt hardware based methods as good data is thrown away to arrive at smaller final picture and what might be deemed un-necssary during design stage might not work in real life.

The real push should be store and transmit uncooked data either to another geo sync satellite ( which probably will be more visible than ground stations ) or to floating stations in indian ocean

Other than that, there should be a push to get a upper atmosphere recon units that can be brought to battlefield at will like the M-55 concept that was flying around in news sometime ago. Does away with the whole problem of atmospheric and image correction for optical images. They can also be fitted with similar payloads ( HSI & ISAR ).
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Post by Bade »

Bandwidth problems may not be insurmountable. ADEOS-II which went dead, used direct download as well as via a GSO parked comm sat to download data.

For a 30 channel sat in SSO orbit roughly 14 orbits per day at 100 min for each orbit, downloading at 5 minute intervals chunks of data (~500MB) mounts to only 140 GB for whole globe daily. For indo-centric coverage 4-5 orbits direct download to ground stations is good enuf.

For hyperspectral imagers with say 1000 channels (max) a factor of 30 more due to channels offset by need for only 1/3 the number of orbits means only a factor 10 more ...1-2 TB daily....peanuts these days.
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Post by Ved »

Arun_S wrote:
What we are talking is polar orbit not GSO correct? Irrespective, the sat will not stay at that spot for long, thus the problem doesnt go away, and there is limited fuel budget...
Correct, the amount of fuel is finite. But small manoeuvres are always done, if only to keep it at the same height and combat orbital decay. The on board fuel caters for this - a finite life, certainly. Thats when the next one should be up. Whoever said it was cheap!
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Post by JCage »

One problem with SAR and FLIR to eyeball SAM sites and other semi static locations is the increasing profusion of radar scattering and thermal camouflage nets and other camouflage measures. Objects on the move will be harder to disguise. Anyhow China has been undertaking active research in defeating radar measures and what China gets, however it may be, Pak gets soon thereafter.


So if radar avoiding/ RCS reduction measures/etc become increasingly common wont setting up an expensive sat chain/ n-w be slightly redundant. Couldnt it be more cost effective to kit out UAV's with SAR and use them instead?


The PAF had signficant problems intercepting the lone Searcher Mk2 that "went over"- if a more reduced RCS UAV is developed and outfitted with Elint and SAR packages perhaps that may be of more use.

Besides, UAV's can be dual tasked- a UAV with a decent payload may carry a moderate sized AGM such as a Nag or a Spike for immediate targetting of high value targets as the US has convincingly demonstrated with the Predator and the Israelis with their UAV's.
Last edited by JCage on 24 Oct 2004 00:20, edited 2 times in total.
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Post by JCage »

About rad hard chips- we can always get newer chips from the commercial market and rad hard them inhouse, if the latter technology is applicable to all or can be modified for other chips.
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Post by ramana »

Here is a link on a proposed system for the US. Dont know if it ever was deployed.

http://www.fas.org/spp/military/program ... ighter.htm
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Post by Arun_S »

JCage wrote:About rad hard chips- we can always get newer chips from the commercial market and rad hard them inhouse, if the latter technology is applicable to all or can be modified for other chips.
IMHO RADHARD is less about packaging and more about fab and grounds up cell level reduendency design.
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Post by JCage »

Ok,it definitely makes sense to as much processing as possible on the ground.
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Post by Ved »

JCage wrote:Ok,it definitely makes sense to as much processing as possible on the ground.
Maybe not. With the advent of HSI and the size of datacubes (256x256) we come to a figure like 13 million - can you imagine sending that down to the ground for processing?
Last edited by Ved on 25 Oct 2004 06:24, edited 1 time in total.
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Post by Cybaru »

Ved wrote:
JCage wrote:Ok,it definitely makes sense to as much processing as possible on the ground.
Maybe not. With the advent of HSI and the size of datacubes (256x256) we come to a figure like 13 million - can you imagine sending that down to the ground for processing?

13 million what ?
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Post by Ved »

cy_baru wrote:
13 million what ?
Pixels, sorry!
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Post by Arun_S »

Ved wrote:
JCage wrote:Ok,it definitely makes sense to as much processing as possible on the ground.
Maybe not. With the advent of HSI and the size of datacubes (256x256) we come to a figure like 13 million - can you imagine sending that down to the ground for processing?
Many ions ago, US and USSR had same problem for photo recce sats. Both approaches had its own challange, US adopted on-board processing and compression (early version of what is MPEG today), USSR went for storage and ground processing. as time passed US approach was the winner, Russia took a long time to realize its folly.

few years ago IAF evaluated ELINT/AWACS from Russia and other sources. Russian solution used ground based processing, eventually IAF rejected that solution.



Today's high resolution imaging coupled with mutispectral sensor results in explosive data volume. I would NOT put my money on ground based processing.

Abelity to process wide sector scan and automatically zoom into interesting feature in realtime instead of waiting second pass has greater merit.
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Post by ramana »

xposted ,,,
Arun_S
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PROBA was launched by PSLV 3 years ago (along with TES).

Proba: The Smart Satellite That Runs Itself

Paris (ESA) Oct 25, 2004
ESA's first microsat has completed three years of successful operations. The size of a large television set, Proba was launched to demonstrate new technologies for future European spacecraft, but continues to provide fantastic images of Earth.

"It is amazing what we have got out of Proba, our first micro-satellite," says Frederic Teston, ESA's Proba Project Manager. "The mission has successfully demonstrated a number of sophisticated technologies in addition to new approaches in spacecraft construction and operations.

"It has 100% lived-up to its full name of 'Project for On-Board Autonomy' - for every day of the last three years the spacecraft performed onboard such functions as steering, navigation, target fly-by estimation and image capture. These are all functions that have to be handled from the ground for larger spacecraft.

"We just provide the latitude, longitude and altitude of a target site, and Proba will handle the rest. The onboard computer steers the spacecraft to the correct position, tilts it correctly, shoots and delivers the image."

The thinking underpinning Proba is that tightly focused missions can be delivered in a short time frame useful to scientists - if the time taken from the original concept to launch and operation can be greatly reduced.

So to simplify its construction - as well as reducing costs - Proba was constructed as much as possible with existing off-the-shelf components, rather than customised space-hardened parts typical for satellites. The good news is that these systems have continued to work well throughout Proba's 1096 days in space.

In polar orbit 600 kilometres above the Earth, each month Proba acquires around 300 images of about 60 separate sites. To date the spacecraft has provided more than 10 000 images from its two onboard imaging instruments: the Compact High Resolution Imaging Spectrometer (CHRIS) and the black and white High Resolution Camera (HRC).

Seeing the world in hyperspectral vision
CHRIS is a compact hyperspectral imager that can return detailed data on the Earth's surface. It sees down to a resolution of 18 metres, in a combination of up to 19 out of a total of 62 spectral bands to provide added environmental information. And the same scene can be viewed from a variety of different angles because Proba is maneuverable enough to perform controlled pitch and roll.

That combined ability to retrieve hyperspectral and multi-angular data makes it especially useful for the study of land vegetation cover. It is also useful for studying the atmosphere and bodies of water. Around 60 scientific teams worldwide are now making use of CHRIS results.

Its high spatial resolution make its data especially useful as a 'bridge' between results from satellite instruments such as Envisat's Medium Resolution Imaging Spectrometer (MERIS) and aerial photography.

CHRIS data are being used to increase the accuracy of wetland monitoring as part of ESA's Globwetland project, supplying information on the environmental condition of these high-biodiversity areas in support of the international Ramsar Convention on Wetlands.

Images from the instrument are being utilised within projects for the ESA-China Dragon Programme, including the study of flood-prone areas. CHRIS images are being used to generate reference maps to be compared with crisis data in order to differentiate flooded areas from permanent water bodies. Chinese researchers have indicated their interest in other applications for the hyperspectral imager, such as mineral prospecting.

CHRIS acquisitions are being coordinated with the German fire-detecting satellite BIRD (Bi-Spectral Infrared Detection). CHRIS has been reacquiring sites of forest fires previously detected by BIRD to identify the extent of the burnt area and identify any vegetation regrowth, in order to study the long-term effects of the blazes.

In a related field, CHRIS images have also been acquired on behalf of the international Charter for Space and Major Disasters, an international agreement to makex space resources available to civil protection agencies responding to natural disasters.

And in the year to come, new planned scientific applications of CHRIS data include precision farming research in Germany, studying spectral reflectance of crop residues and soils in France, biodiversity monitoring in Africa, coastal area mapping in the south of Chile and archaeological projects in Spain.

Proba's additional payload
The other imager on board Proba is the compact HRC, which has an even higher spatial resolution of five metres, acquiring monochromatic images with an area of 25 square kilometres. As well as studying the Earth, the spacecraft also returns data on its own immediate environment. Also aboard is a radiation detector called the Standard Radiation Environment Monitor (SREM), used to investigate the energetic particles responsible for the polar auroras, which during the last three years has made it possible to better model the radiation environment around Earth.

Another instrument in its payload is the Debris In-orbit Evaluator (DEBIE) which monitors tiny micrometeoroids or space debris between a centimeter to under a millimetre in diameter.

About Proba
Proba is a micro-satellite developed by ESA's General Study and Technology Programme (GSTP) and built by an industrial consortium led by the Belgian company Verhaert, launched from India on 22 October 2001 and operated from ESA's Redu Ground Station in Belgium. Its CHRIS instrument, funded by the British National Space Centre (BNSC), has been built by the UK company SIRA Space.

Proba's unique capabilities also makes it a useful resource in the development of ESA's proposed SPECTRA (Surface Processes and Ecosystem Changes Through Response Analysis) mission, an Earth Explorer spacecraft intended to study terrestrial vegetation across the world's major biological communities or 'biomes'. If selected for development, SPECTRA would launch around 2012. Proba was intended as a one-year technology demonstration mission, but has since had its lifetime extended to serve as an Earth Observation mission.

A follow-on technology demonstrator called Proba-2 is due to be deployed by ESA by the end of 2007. As with its predecessor the new mission will prove new technologies and new products in orbit.

The system built around these developments is intended to support a Sun observation and plasma measurement mission. A new type of solar spectrometer combined with high spacecraft performance will provide for the first time, high-data rate imaging of the Sun.
--------------
The CHRIS instrument with better resolution and on-board image compression would do the job for tech demostrator. But isnt TSP too small a fish for hyperspectral stuff? Maybe the mission should be expanded to monitor the area of interest.
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Post by Pmangalik »

Hi Guys,

I used to be involved with the SDI stuff and thought that this article may be interesting in light of India's interest with Space-based Sensors:

U.S physics blunder almost ended space programs
Friday, 8 December 2000
By Richard Sale, UPI Terrorism Correspondent

WASHINGTON, Dec. 8 (UPI) -- In 1964, a U.S atomic bomb blast in the Van
Allen belts surrounding the earth almost permanently ended the U.S. space
program, according to retired Gen. Ken Hannegan of the Defense Nuclear
Agency. Hannegan spoke recently with United Press International.

Hannegan acknowledged that during a 1964 test for a new U.S.
anti-satellite weapon system, the United States fired an atomic bomb of
about 50 KT (or two and a half times the strength of the Nakasaki bomb) in
the Van Allen belts -- areas of radiation and charged particles which
surround the earth's upper atmosphere and which are held in place by the
earth's magnetic field.

According to former Lockheed scientist Maxwell Hunter, who worked on the
program, "It was a military idea -- that you might be able to create a
weapon by artificially pumping up radiation in the belts by detonating
explosions in them and trapping the radiation."

In the 1960s, prodded by concerns over a Soviet orbital bombing threat,
the U.S. Air Force had begun work on a nuclear-armed direct ascent
anti-satellite system targeted at Soviet low-altitude satellites. The
project was based on Kwajalein Island in the Pacific. Another companion
effort was based on Johnston Island, which is due east, and a little north
of the Marshall Islands. The Johnston Island testing used nuclear-armed Thor
intermediate range ballistic missiles, according to Hunter and other former
Lockheed officials who asked not to be named.

Richard Freeman, a former vice president of Rockwell International and
E-Systems, who was involved in many military "black curtain" or secret U.S.
space programs, said that Johnston was picked because its location was
excellent for interception Soviet satellites on their first orbital passes.

In a test that was part of a program called Project Century, the atomic
bomb was exploded at an altitude of between 300 to 400 miles, "not a high
shot," said Hunter. "We wanted to fill up the belts at the point where they
were closest to earth."

But the effect was totally unplanned for.

"It unexpectedly disabled U.S. and Soviet satellites," Hunter said,
adding, "You have to remember that we had very primitive satellites in those
days that lacked any protective shields."

But another effect became extremely disconcerting. Hunter said that the
bomb blast loaded the belts longitudinally in a pie shape from pole to pole.
But where the Air Force had expected the radiation from the blast to remain
in the belts for only two days, "There was a trapped radiation phenomena" --
in other words, the extraordinarily high radiation levels refused to
disperse. In fact, Hunter said, the energy from the A-bomb blast stayed in
the belts "for over a year, maybe more." Hannegan said that the trapped
radiation knocked out all American and Soviet equipment that passed through
it. "The area was militarily neutral," said Hannegan.

Hunter said a dispute then broke out within the military and scientific
community. "There were discussions about us having poisoned space for good,
about having destroyed all satellites. An equal number of scientists
disagreed, but everyone agreed that such a weapon would only end up blinding
ourselves," he said.

One effect of the panic was the strengthening of U.S. satellites against
radiation that in the end would help shield them from ground-based laser
attacks. According to U.S. intelligence sources, who asked not to be named,
such attacks damaged super-sophisticated American spy satellites deployed to
monitor missile and spacecraft launches at the major Russian space center.

These sources said that the Soviets fired ground-based lasers to cripple
sensitive optical equipment attempting to scan launches at Tyuratam to
obtain a variety of sensitive military information including payloads and
throw weights. The Soviet laser "hosings" of costly satellites, details of
which remain classified, occurred throughout the 1980s and into the early
1990s, and sent U.S. scientists scrambling to shield the space surveillance
system.

According to a former Senate Intelligence Committee chief of staff, Angelo
Codevilla, the Soviets regularly "pulsed" or targeted lasers on U.S.
satellites. A senior Air Force official said that the U.S. had decided to
keep evidence of the laser attacks hushed up for a variety of reasons.

The official said that first, it makes our equipment "look bad" but more
important, the United States has used the collective evidence as a
bargaining chip in strategic arms limitation talks. "U.S. negotiators say,
look, we know this is happening and we are willing to make it public if you
don't give us this or that concession," said the official.

In 1976, a KH-11 or Code 1010 satellite was "painted" by a Soviet laser
and sustained "permanent damage," according to a senior Air Force official.
This source said that such paintings continued into the late 1980s.

According to U.S. intelligence sources, the attempt to use U.S. satellites
to view launches at Tyuratem, stemmed from concern over the Soviet launch of
"killer satellites" that would be used in the event of war. Although U.S.
air defense radar is capable of tracking the smallest objects orbiting
Earth, if a satellite is inactive or "dark" the Pentagon does not become
aware of its mission until it becomes activated, and by then it's too late.

These Pentagon sources said it was common practice for the Soviets to
launch satellites three at a time with only two becoming immediately active.
Such dark satellites are highly unlikely to be identified as a threat, these
U.S. analysts said.

Air Force officials told UPI that for years the Soviets had a
"battle-ready" ground-based laser at Saryshagan that they said they believed
had been involved in past blindings of U.S. spacecraft.

When the Soviet Union dissolved, it was in the process of building a new
battle-ready laser at Nurek in Tadzhikstan and a second 500 miles away at
Khazakstan in the Caucasus Mountains. Four more ground laser battle stations
were planned, one begun on mountains near Dushanbe and another between Nruek
and Dushambe and two more at unidentified areas. A Pentagon source said the
collapse of the Soviet Union prevented their being completed.

But the result of the "hosings" of U.S. equipment was positive. The United
States moved quickly to install laser warning receivers on its newest
generation of low-orbit spacecraft, U.S. intelligence sources said. The
receivers have allowed time for evasive action and have assisted ground
controllers seeking to prove the Soviets had inflicted the damage.

One State Dept. analyst said that the whole Star Wars system of the Reagan
presidency was the result of Soviets "messing around with our satellites."

And although official U.S. policy was not to interfere with Soviet
satellites, the U.S. scientists often targeted Soviet spacecraft trying to
observe the launch of U.S. missiles involved in a Defense Research Projects
Agency program at Vandenberg Air Force Base in California. U.S. scientists
targeted the Soviet satellites with beams from ground-based facilities in
Maui and Oahu, Hawaii and San Juan Capistrano, Calif., according to former
Air Force officials.

Although most "hosings" of Soviet craft were used for "range finding
purposes," Richard Freeman said that the Capistrano facility, which has
since moved to Cloud Croft, N.M. "possessed "a full anti-satellite
capability."

Freeman added: "If we didn't' damage Soviet equipment, it wasn't because
we weren't trying." The U.S. has since moved to jam Russian satellite radio
communications to ground stations, he said.

So why did the earlier Starfish blunder occur? "We didn't know enough yet
about plasma physics," said Hannegan. "We just didn't understand it yet."

But former military space expert, Clarence Robinson said that the reason
the United States probably stopped such testing was because it discovered
"that there isn't anything you do to the enemy that you don't end up doing
to yourself."
Locked