The wide, coarser of the two colour cameras on India's first remote sensing satellites, IRS-1A and IRS-1B. It saw the ground in four colours at about 72.5 m detail.
LISS-I recorded how brightly the ground reflects sunlight in four bands: blue, green, red and near-infrared. Healthy plants reflect strongly in near-infrared, so the camera could separate crops and forests from bare soil and water.
Each picture element covered about 72.5 m of ground, and the camera swept a strip about 148 km wide.
LISS stands for Linear Imaging Self-Scanning Sensor. It is a pushbroom camera. Instead of a moving mirror, it uses a long line of 2,048 light detectors (a CCD) for each band. As the satellite flies over, the line builds the picture one row at a time.
Each band had its own lens and filter. Small lamps (LEDs) inside the camera were switched on to check the detectors while in orbit.
IRS-1A (1988) and IRS-1B (1991) each carried one LISS-I alongside two sharper LISS-II cameras. Neither satellite had a recorder, so pictures were sent down live as the satellite passed over a ground station. IRS-1A served until July 1996 and IRS-1B until December 2003.