IRS 1B

RS 1B had Improved features compared to its predecessor : gyro referencing for better orientation sensing,time tagged commanding (IRS-1A) facility for more flexilibility in camera operation and line count information for better data product generation. Mission completed on December 20, 2003 after serving for 12 years and 4 months.

IRS 1B Specifications

Mission Category Operational Remote Sensing
Launch Date Category August 29, 1991
Launch Site Category Baikanur Cosmodrome Kazakhstan
Launch Vehicle Vostok
Weight 975 kg
Onboard Power 600 Watts
Communication S-band, X-band and VHF(commanding only)
Stabilization Three axis body stabilized (zero momentum) with 4 Reactions Wheels, Magnetic torquers
RCS Monopropellant Hydrazine based with sixteen 1 Newton thrusters
Payload Three solid state Push Broom Cameras LISS-1(72.5 metre resolution), LISS-2A and LISS-2B (36.25 metre resolution)
Orbit Polar Sun Synchronous
Altitude 904 Km
Inclination 99.08 Degrees
Local Time 10.30 a.m. (descending node)
Repetivity 22 days (307 orbits)
Mission Completed December 20, 2003

IRS 1B Sensors

Characteristics of LISS I Sensor

It has four spectral bands in the range of 0.45 to 0.86 μm (0.45 to 0.53 μm to 0.59 μm, 0.62 to 0.68 μm and 0.77 to 0.86 μm) in the visible and near infrared range with two different spatial resolutions of 72.5 m. and 36.25 meter from one no. of open LISS-1 and two nos. of LISS-2 sensors respectively. It provides repetitive coverage after every 22 days. Like all other LANDSAT/ SPOT missions which are designed for global coverage IRS is also in sun synchronous, polar orbit at about 900 km altitude and cover a width of 148 km. on ground. It uses linear array detectors (CCD) like SPOT.

Sensor LISS I
Resolution 72.5
Swath 148 Km
Repetivity 22 Days
Spectral Bands 0.45-0.52 microns(B1)
0.52-0.59 microns(B2)
0.62-0.68 microns(B3)
0.77-0.86 microns(B4)

Characteristics of LISS II Sensor

Sensor LISS II
Resolution 36.25
Swath 74 X 2 Km
Repetivity 22 Days
Spectral Bands 0.45-0.52 microns(B1)
0.52-0.59 microns(B2)
0.62-0.68 microns(B3)
0.77-0.86 microns(B4)

IRS 1B