I am beginning to doubt that the CY1 cameras are of the pushbroom type (or the Linear Imaging & Self Scanning - LISS sensors as ISRO normally terms it). I wonder if they are more like normal digital camera sensors that capture an image over an area i.e. across and along the direction of travel. The INSAT cameras are of that type since they have no relative motion with respect to the Earth. Here's why I am inclined to think that: (bear with me please - I know I could be waaaay off base here
(I also found out that the Kaguya Terrain Camera is of the pushbroom type but it also has HDTV sensors with 2.2 M pixel resolution)
1. ISRO normally explicitly refers to pushbroom cameras as LISS sensors like they have for the IRS series including Resourcesat-1 but for CY1, there's no mention of linear sensors when refering to the TMC aboard CY1. They do mention a swath of 20 km and a resolution of 5 m but this is how they put it
It can image a strip of lunar surface which is 20 km wide and resolution of this CCD camera is 5 m.
2. The images captured of the earth - one partial earth image from 9000 km, one whole Earth image taken at 70000 km and a whole Moon image taken at 311200 km do not appear to be images taken by linear imaging cameras. some rough calculations:
To have a 5 m resolution at 100 km from the lunar surface, the angular resolution of the camera is 5.0E-5 radians. At 311200 km, the Moon would subtend an angle of 0.011 radians only and the relative motion of CY1 wrt the Moon would be very small. So to image the full moon, CY1 would have to be manually moved to be able to scan the full Moon in a minimum of 223 steps - too much trouble if you ask me just to take a poor quality image. As far as can tell, CY1 is not designed to be steerable - I couldn't find any mention of steerability which might mean that thrusters would be required to orient the satellite, no? Why waste all that fuel to no purpose? Then at 9000 km only a partial image appears to be captured. Using a globe I estimated that the area captured covers around 18 degrees of the Earth's surface (from somewhere below the Equator to roughly the Tropic of Capricon) . At 9000 km this is roughly 0.2 radians or 20 km at 100 km distance. This could simply confirm that the swatch of the TMC is 20 km or it might imply that the image area would be 20x20 km at 100 km altitude.
Like I said, I could be completely wrong, so if anyone has better info, please post!