digital surface model with 5 m post spacing
digital surface model
with 5 m post spacing

LISS-III Camera

Optics and electronics

LISS-III operates in four spectral bands. There is a separate optics and detector array for each band. Three bands (B2, B3 and B4) are in the visible and near infrared region. B5 is in short wave infrared region. Since the first three bands of LISS-III are in the same spectral region as IRS-1A/1B/P2 sensors, the same nomenclature is continued. Bands B2, B3 and B4 of IRS-1C are therefore identical to that of IRS-1A/1B/P2.

Inflight calibration

The inflight calibration of the camera is carried out using LEDs. Six Non zero exposure levels spanning the dynamic range are provided for each detector. Four LEDs are used for illumination. Two LEDs operate at a time to cover half the length of CCD. The LEDs are operated in pulsed mode and the duration during which the LEDs are 'ON' is varied in specific steps. Each LED has a cylindrical lens to maximize the intensity. For Band 5, the LEDs have very small angular divergence. The CCD detector integrates the light falling on it during one readout period. A calibration cycle comprises of 2048 lines. The time taken for one calibration cycle of LISS-III is 7.3 seconds. The Band 5 calibration data is multiplexed with data of other bands.