Indian Space Program Discussion

Bade · Post by **Bade** » 24 Apr 2011 08:11

Here is what Wiki says "remote sensing" is:

There are two main types of remote sensing: passive remote sensing and active remote sensing. Passive sensors detect natural radiation that is emitted or reflected by the object or surrounding area being observed. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography, infrared, charge-coupled devices, and radiometers. Active collection, on the other hand, emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR is an example of active remote sensing where the time delay between emission and return is measured, establishing the location, height, speed and direction of an object.

http://en.wikipedia.org/wiki/Remote_sensing

That pretty much covers even MET payloads if there is lingering doubts. CCDs of course are usually Imagers and extensively used for land imaging like in IRS/Landsat etc.

Bade · Post by **Bade** » 24 Apr 2011 08:26

http://www.isro.org/scripts/remotesensi ... tions.aspx
This link is quite important to understand why ISRO has remained focused on Land remote sensing alone. The primary driver are the internal needs that they need to support when canvassing for satellite projects from GoI. The spin off in making money on the side with data sale is really secondary to ISRO goals as set by GoI's needs.

I was earlier thinking along the lines that such focus on land applications alone may be due to $$$ to be made in the International market as seen by Antrix. Maybe not. The competition is probably already stiff from DigiGlobe and others like ESA who make the data access sometimes even free of cost.

In any case ISRO needs to speed up and broaden its IRS series, the beginnings are there to see already and taking shape slowly.

juvva · Post by **juvva** » 24 Apr 2011 09:35

Bade wrote:
They make the IRS system the largest civilian remote-sensing satellite constellation in the world.
There we go again despite all the links provided a few pages back. Remote-sensing has been redefined to suit a marketing slogan. Nuke thread is an example of this sort of indulgence. Wonder why this piskology to claim "largest" and "indigenous" whatever. We need to get over this fixation which is in the same league as using the prefix of "super".

I do not think anyone from SAC A'bad or ISAC Blr will use such a description. They would know for sure if the claim is true or not.

ISRO ( at least their website) does make the claim:

http://www.isro.org/satellites/earthobs ... lites.aspx

"
......
IRS is the largest civilian remote sensing satellite constellation in the world providing imageries in a variety of spatial resolutions, spectral bands and swaths.
......
"

Bade · Post by **Bade** » 24 Apr 2011 09:47

Arre baba, it is all obfuscation in using the English language to make a point onlee. What does a "satellite constellation" mean ? Ask ISRO or you can answer too with some thought.

If you make the same bar soap in different flavors (color, smell) but for the same use (cleaning) can you also call it a "constellation of saboon" implying for all cleaning purposes (but not clearly specifying the use). If you can then you have the largest constellation of soaps, even if it means you cannot clean anything else but for your body with it.

Others may not have so many flavors of the same bar soaps, but have soap products for every variety of cleaning you can think of. Hope that explains the difference.

SSSalvi · Post by **SSSalvi** » 24 Apr 2011 20:56

Does any one have a real status of Resourcesat-2 launched last week?

I am able to get orbit details of X sat and Youthsat .. as well as the last stage of PSLV debris but right from day 1 there are only these 3 objects which are being tracked/found by independent international observing entities. These entities track optically objects which appear newly ... irrespective of whether it is a live satellite or debris. So even if the satellite is dead it will be reported by these organizations.

E.g. n2yo.com gives following status for xsat and youthsat and resourcesat:

xsat:
Two Line Element Set (TLE):

1 37389U 11015C 11114.17309777 .00000643 00000-0 30037-3 0 133
2 37389 098.7731 186.3272 0013186 289.4202 070.5580 14.23801314 554

youthsat:
Two Line Element Set (TLE):

1 37388U 11015B 11114.17371983 .00000728 00000-0 33899-3 0 133
2 37388 098.7730 186.3268 0013510 285.7371 074.2344 14.23577312 562

Resorsesat:
Two Line Element Set (TLE):

No Keplerian data

=======

Where is Resoursesat-2? Can anyone throw light?

Bade · Post by **Bade** » 24 Apr 2011 23:41

ISRO may not have released that information yet, the exact orbital parameters. Isn't that normal for the course ? In the past I do not recall seeing TLE data days within launch. Maybe, I am wrong on that as the info is from METSAT launch days when there was a private site (Celestrak ?) by a which used to keep that info for all orbiting satellites.

Bade · Post by **Bade** » 24 Apr 2011 23:48

http://celestrak.com/NORAD/elements/tle-new.txt

YOUTHSAT
1 37388U 11015B 11114.17371983 .00000728 00000-0 33899-3 0 133
2 37388 98.7730 186.3268 0013510 285.7371 74.2344 14.23577312 562
X-SAT
1 37389U 11015C 11114.17309777 .00000643 00000-0 30037-3 0 133
2 37389 98.7731 186.3272 0013186 289.4202 70.5580 14.23801314 554
PSLV R/B
1 37390U 11015D 11114.23516256 -.00000000 00000-0 18086-4 0 100
2 37390 98.6598 186.2317 0018130 340.9665 19.0836 14.26713815 569
2011-016A
1 37392U 11016A 11113.58334318 -.00000337 00000-0 00000+0 0 23
2 37392 6.1110 2.4018 7283457 178.1037 188.2248 2.27511207 14
2011-016B
1 37393U 11016B 11114.01833299 -.00000356 00000-0 00000+0 0 59
2 37393 5.9975 2.1031 7280353 178.5285 185.7305 2.27837830 13
2011-016C
1 37394U 11016C 11113.59875888 -.00000369 00000-0 00000+0 0 34
2 37394 5.6297 5.8222 7283961 174.6446 202.9553 2.28435741 06
2011-016D
1 37395U 11016D 11114.01879382 -.00000356 00000-0 00000+0 0 43
2 37395 6.0026 2.0894 7282489 178.6352 185.8404 2.27744106 12

SSSalvi · Post by **SSSalvi** » 25 Apr 2011 09:15

^^^

PSLV R/B .. that is the last stage ( in which satellites are housed ).

That entity is there in every launch.
In fact Celestrak does not identify objects till they are identified ... for the launch that took place yesterday ( appears to be an equtorial 12hr orbit ) It has identified objects as 2011-016 a,b,c,d pending confirmation. ( actually they are from Ariene5 Launch .. Yahsat and Intelsat new dawn )

Till 2 days back they did not call PSLV objects as Youthsat,Xsat and PSLV R/B. They called them ( 2011 - 015B,C,D ( Oh that rings a bell .. 015A is not listed .. will write to Kelso of celestrak )

SSSalvi · Post by **SSSalvi** » 25 Apr 2011 09:19

For info:

Tweet by Kelso of Celestrak on 22nd

TSKelso T.S. Kelso
Now have IDs for Resourcesat-2 launch, but no TLEs yet for Resourcesat-2 itself. Not sure why. Launch notification in the works.
22 Apr

thammu · Post by **thammu** » 25 Apr 2011 19:29

Ariane 5 enjoys second successful launch for 2011 @ http://www.space-travel.com/reports/Ari ... 1_999.html

.....The payload mass for this launch was 10 064 kg; the satellites totalled 8965 kg, with payload adapters and dispensers making up the additional 1099 kg.....

Even our GSLV Mark 3, if it would have been successful, will be nowhere near this...

Will we ever catch up...

PratikDas · Post by **PratikDas** » 25 Apr 2011 19:39

thammu ji, all you need is one good cryo OR semi-cryo engine, and then you can cluster them together for ever heavier payloads. The Ariane way might not be in India's near future. The Soyuz and Falcon way might be.

http://upload.wikimedia.org/wikipedia/c ... ngines.jpg

sanjeevji · Post by **sanjeevji** » 26 Apr 2011 08:05

ISRO 25 April: RESOURCESAT-2, YOUTHSAT and X-SAT Satellites Functioning Satisfactorily

In its 17th consecutive successful flight, Indias Polar Satellite Launch Vehicle (PSLV-C16) injected three Satellites viz. RESOURCESAT-2, YOUTHSAT and X-SAT (of Nanyang Technical University, Singapore) into their intended Polar Sun-synchronous orbits on April 20, 2011 from Satish Dhawan Space Centre (SDSC), Sriharikota. All the three satellites were placed in the targeted orbits with high precision.

The orbital parameters achieved by PSLV-C16 while injecting the primary Satellite RESOURCESAT-2 were as follows:

Orbital Parameter Specification Targeted Achieved by PSLV- C16
Perigee 815 + 20 km 808.6 km
Apogee 821 + 20 km 815.6 km
Orbital Inclination 98.72 + 0.2 degree 98.77 degree

With the precise injection of the RESOURCESAT-2 Satellite, about 20 kg of the fuel allocated for the probable dispersions in injection could be saved. This would help in enhancing the operational life of the Satellite.

RESOURCESAT - 2

Immediately after the injection of the satellite, the two solar panels were deployed. The three Imaging Cameras have been oriented towards Earth. All operations and health checks required prior to switching on the three Imaging Cameras have been satisfactorily completed.

Orbital trimming manoeuvre was conducted successfully on April 22, 2011, and RESOURCESAT-2 is now placed in the final orbital configuration in a sun-synchronous polar orbit with perigee of 813 km; apogee of 825 km and inclination of 98.78 degree.

Operation of the Imaging cameras is scheduled to commence on April 28, 2011. The first imaging pass on April 28th is expected to cover about 3000 km stretch of Indian landmass from JOSHIMUT (in Uttarakhand) to KANNUR (in Kerala).

SSSalvi · Post by **SSSalvi** » 27 Apr 2011 21:04

Resourcesat-2 orbit details are now available.
Orbit pattern can be seen here

RamaY · Post by **RamaY** » 27 Apr 2011 21:18

^ Good blog SSSalvi ji.

It made me to search orbits of other satellites and understand how frequently India can get updated pictures of a given space.

Sean Rowe · Post by **Sean Rowe** » 28 Apr 2011 16:53

http://isro.org/pressrelease/scripts/pr ... Apr28_2011

Ressourcesat-2 sending High quality images

RESOURCESAT-2 Sending High Quality Imagery

The RESOURCESAT-2 satellite, which was launched successfully by PSLV-C16 on April 20, 2011, into a polar sun-synchronous orbit is working satisfactorily. The initial phase of operations on the satellite has been completed successfully.

The three camera systems onboard the RESOURCESAT-2 satellite were switched on today (April 28, 2011) and images of high quality have been received. The first imagery covering about 3000 km stretch of Indian landmass from JOSHIMUT in Uttarakhand to KANNUR in Kerala was received and processed at the National Remote Sensing Centre (NRSC) Earth Station at Shadnagar near Hyderabad .

SSridhar · Post by **SSridhar** » 29 Apr 2011 07:28

ISRO preparing for 3 more PSLV launches

“PSLV C-17 will be launched in July and it will carry GSAT-12, a communication satellite. PSLV-C18 will be launched in September and it will carry a weather forecast satellite. PSLV-C19 with a payload of Radar Imaging Satellite (RISAT) will be launched by this year end,” Mr. Chandradathan {Director, Sathish Dhawan Space Centre, Sriharikota} said.

“Recently launched PSLV-C16 precisely injected its payloads into intended orbits without wasting even a bit of propellant,” he said.

Later speaking to reporters, Mr. Chandradathan said that building of GSLV-Mk III will be over by 2012 end and launch would be in the next year.

“GSLV-Mk III has three stages. The first stage, Solid propellant booster S-200 has been tested and qualified; Second and liquid propellant stage called L-110 has also been tested. Work is yet to be completed in third and important stage, the cryogenic stage,” he said.

chackojoseph · Post by **chackojoseph** » 02 May 2011 18:23

ISRO's supercomputer "SAGA-220" is India's fastest

SaiK · Post by **SaiK** » 02 May 2011 19:55

any direction set to match or exceed peta flop scale? any requirements seen especially when we are talking about nano-tech future.

Gagan · Post by **Gagan** » 02 May 2011 20:14

How fast was the Tata IBM supercomputer at Pune?

chackojoseph · Post by **chackojoseph** » 02 May 2011 20:17

Gagan wrote:How fast was the Tata IBM supercomputer at Pune?

Eka is 170 teraflops.

Austin · Post by **Austin** » 08 May 2011 12:02

CAG report on ISRO satellites

Pranav · Post by **Pranav** » 09 May 2011 09:21

A description of US satellite surveillance capabilities:

WATCHING 'THE PACER'

Once the Americans had spotted the compound in August last year, they quickly began monitoring it with spy satellites.

"We put 24/7 eyes on it," said an intelligence source. Pakistani CIA agents began renting a nearby house, with windows made up of two-way mirrors, while Task Force Orange focused on providing the intelligence that would be required to ensure that any eventual operation went as smoothly as possible.

The National Geospatial-Intelligence Agency, one of the most sophisticated non-violent weapons in America's armoury, swung into action. Using satellite images, information from sources and transcripts of intercepted phone calls, it produced imagery analysis that described in detail the compound's dimensions, features and even the "pattern of life" behaviour of its inhabitants.

Yet the spies were unable to capture an image of the al-Qa'ida leader. Panetta told the PBS television network: "We noticed an individual who was pacing in the courtyard who at least had some of the appearances (of bin Laden), but we were never able to verify that, in fact, it was him."

The watchers began referring to this man as "The Pacer". His routine suggested that as much as he never left the compound he was practically a prisoner within it.

The White House asked the NGA to estimate his height. They came back at between 5ft 8in (172cm) and 6ft 8in (203cm). It was a broad range, caused by the extreme vertical angle of the satellite picture, but consistent with bin Laden. Panetta told Obama it was the best "window of opportunity" they had had since Tora Bora.

http://www.theaustralian.com.au/news/wo ... 6052094513

IMHO, it is not impossible with present day technology to get 24 x 7 live video of any required location. Recall that with a constellation of 24 satellites (such as the GPS system) one can have 4 satellites in the sky at any place at any time.

See also http://en.wikipedia.org/wiki/Gorgon_Stare . For a description of some problems encountered see http://www.popsci.com/technology/articl ... arly-tests

Rupesh · Post by **Rupesh** » 09 May 2011 09:59

^^^
If placed in geo stationary orbit, it is possible to provide 24/7 coverage of the same location.. though I doubt abt the image quality

SSSalvi · Post by **SSSalvi** » 09 May 2011 15:48

@Pranav

I think what he refers as "24/7" is the rented house nearby.
Estimation of Height of the person may be with shadow and Sun angle algorithms.
The GPS sats are at such a height you can't get a very high resolution .. what I mean is 24/7 survey lance of a specific place in hi-res by satellite is not possible.
@ Rupesh
True you won't get hi-def imagery by geosync sats.

Pranav · Post by **Pranav** » 09 May 2011 17:59

SSSalvi wrote:@Pranav

I think what he refers as "24/7" is the rented house nearby.
Estimation of Height of the person may be with shadow and Sun angle algorithms.
The GPS sats are at such a height you can't get a very high resolution .. what I mean is 24/7 survey lance of a specific place in hi-res by satellite is not possible.
@ Rupesh
True you won't get hi-def imagery by geosync sats.

It may be possible for resolution to be improved significantly using synthetic aperture cameras (even in visible spectrum).

Here is an interesting PhD thesis: Synthetic Aperture Imaging using Dense Camera Arrays - http://graphics.stanford.edu/~vaibhav/pubs/thesis.html

In the scenario we are discussing, the synthetic aperture would be created by the motion of the satellite (rather than by multiple cameras, as discussed in Vaibhav's thesis).

One wonders what this Vaibhav Vaish is doing these days.

Pranav · Post by **Pranav** » 09 May 2011 18:25

The TecSar satellite (http://en.wikipedia.org/wiki/TecSAR) reportedly has a 10 cm resolution in the X-band, and its orbit is about 500 km.

GPS satellites have an orbit of about 20,000 km.

So yes, there do seem to be difficulties in achieving global 24x7 coverage.

But it would be good to push the envelope to see how far one can go. For example, using the visible spectrum (with much lower wavelength than TecSar's X-band) we should be able to get better resolution, especially if we use synthetic aperture techniques.

Pranav · Post by **Pranav** » 09 May 2011 18:46

Here is the formula for angular resolution of a camera (http://en.wikipedia.org/wiki/Angular_resolution):

Here theta is the angular resolution, lambda is wavelength and D is aperture.

Now visible light has a wavelength that is about 50,000 times smaller than the X-band used by TecSar.

So, in theory, it should be possible to get much better resolution, especially with synthetic aperture techniques. Which means satellites can be at higher altitudes, which means fewer satellites should be enough.

It would be interesting to calculate what can be done with a spherical array of cameras (like Gorgon Stare - http://en.wikipedia.org/wiki/Gorgon_Stare), operating in the visible spectrum, with Synthetic Aperture imaging. What kind of resolution would be possible with a constellation of satellites at 10,000 km altitude, say?

Obviously the disadvantages of visible light being no coverage at night, and can't see through clouds.

Also, I haven't taken into account any limitations that may come from the sensor arrays (CCDs?)

dinakar · Post by **dinakar** » 10 May 2011 17:40

Resourcesat-2 sends images of Delhi, Surat

High quality images of the Indian landmass and other countries beamed by India’s remote-sensing satellite, Resourcesat-2, were presented to Prime Minister Manmohan Singh in New Delhi on Monday, by the top-brass of the Indian Space Research Organisation (ISRO).

This Hindu article is carrying three pictures Taken by Resourcesat-2. One from Delhi, second from Bareilly and the third one showing Dubai.

Kailash · Post by **Kailash** » 11 May 2011 13:12

Hope this was not posted earlier..

ISRO joins bid to clean space debris

But the big question is 'how?' Space theorists across the globe have suggested solutions as colourful as nets to laser beams, but the IADC is more realistic.

''Whether to remove satellites to a different, safer, orbit after a specified number of years is one of the options being considered,'' Adimoorthi, who is a former chairman of IADC, said.

The threat posed by orbital debris has become so real that space agencies are spending significant sums to monitor orbits and debris on a daily basis.

For instance, ISRO's space debris unit had kept its eyes skinned for hurtling junk before okaying the launch window for the recent PSLV C16 mission.

Definitely dual use stuff

we should develop the skills in this area

Kailash · Post by **Kailash** » 12 May 2011 14:37

India designing reusable spacecraft

Director of Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, P S Veeraraghavan on Wednesday said India`s space scientists are designing a reusable space craft, which is likely to be launched in 2030. The Indian Space Research Organisation (ISRO) is currently working on Human Spacelift Project or the man mission in 2015 and Chandrayan-II in 2013, he said.

"The winged Reusable Launch Vehicle Technology Demonstrator (RLV-TD) has already been configured. It will give India an edge in space science as no country except the US has yet launched a reusable satellite launch vehicle," he added.

Will · Post by **Will** » 12 May 2011 15:41

Kailash wrote:India designing reusable spacecraft

Director of Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, P S Veeraraghavan on Wednesday said India`s space scientists are designing a reusable space craft, which is likely to be launched in 2030. The Indian Space Research Organisation (ISRO) is currently working on Human Spacelift Project or the man mission in 2015 and Chandrayan-II in 2013, he said.

"The winged Reusable Launch Vehicle Technology Demonstrator (RLV-TD) has already been configured. It will give India an edge in space science as no country except the US has yet launched a reusable satellite launch vehicle," he added.

2030? Thought this was scheduled for this decade......

Varoon Shekhar · Post by **Varoon Shekhar** » 12 May 2011 18:34

Is the 2030 timeframe meant for a reusable *passenger* spaceplane, like a space shuttle. Long before that, ISRO should have tested an unmanned reusable vehicle to carry payloads into orbit. Or do they mean *any* reusable rocket? A 2030 launch date would be very disappointing.

Sean Rowe · Post by **Sean Rowe** » 12 May 2011 19:00

May be they mean 2013...

RonyKJ · Post by **RonyKJ** » 12 May 2011 20:43

Some of these jokers come out and make these statements every once in a while.
The first air-breathing rocket was flown in early 90's called ABR-200. Since then
they have been rehashing the same thing under different names just so that people
can keep their jobs. Every few years, they will come out with a projected flight date, which
will always be 20 years in the future. What irks me most is that they then also claim that
India will be the second country to have this capability. Chairman ISRO seems to have learned
a good lesson after all the failures. He does not open his mouth nowadays, something he
should have learned to do from his kathakali training

Austin · Post by **Austin** » 15 May 2011 18:41

ISRO puts on hold moon mission Chandrayaan 2

symontk · Post by **symontk** » 15 May 2011 20:20

New facilities of ISRO coming

In Karnataka - ISRO plans R&D centre, integration of sub-systems facility
Thiruvananthapuram would have facilities for hypersonic and plasma wind tunnels to support the rocket making facilities.
SriHarikota to have Integration facilities

http://www.thehindubusinessline.com/...cle2019221.ece
http://www.thehindubusinessline.com/...cle2018972.ece

abhishek-nayak · Post by **abhishek-nayak** » 16 May 2011 07:36

Austin wrote:ISRO puts on hold moon mission Chandrayaan 2

What a shame!! Even private companies like SPACEX which has no more than 1000 employees is more capable than ISRO.

ramana · Post by **ramana** » 16 May 2011 08:25

Austin wrote:ISRO puts on hold moon mission Chandrayaan 2

Good job. They want to focus on GSLV development and not hurry up.

Austin, Please post the detail quotes for they are worth it. The headline is a misleading

.

sum · Post by **sum** » 16 May 2011 08:30

abhishek-nayak wrote:
What a shame!! Even private companies like SPACEX which has no more than 1000 employees is more capable than ISRO.

Really?

Hiten · Post by **Hiten** » 16 May 2011 08:38

this video released by ISRO some time back explaining the stacking process and a brief description of each stage of the GSLV

http://www.youtube.com/watch?v=cuqYLHaLB5M