IRS (Indian Remote Sensing) program was written as India one of the most high technology national programs. The program aim was the space technologies development in the India national economic development, interests. The IRS program main task is different resources (land, farmland, manpower, etc) effective management and optimal use. To solve these tasks the Indian government Space Department started the IRS program in 1988 beginning with the IRS 1A space venicle launch.
The IRS-1 C satellite was successfully launched into the polar orbit on December 28th, 1995 by a Russian booster. The first images were received at the beginning of January 1996.
Following to it on September 29th, 1997 to the polar orbit by the PSLV booster there was launched one more similar satellite. The IRS satellites main task is securing the systematic and repeating data on the earth surface at almost constant illumination conditions receipt.

IRS 1C/1D space venicle technical characteristics

space venicle nameIRS-1C/1D
CountryIndia
DesignerISRO
OperatorISRO
BoosterMolniya-M / PSLV
Launch dateDecember 28th, 1995/September 29th, 1997
Orbit:
              altitude, km
              inclination, deg
              revisiting period, min
              equator crossing time, hour
Day sun-synchronous
817/780
98.6
101,35/100,55
Platform:
                     survey equipment
                     declination angles, deg
IRS-1
PAN, LISS-3, WiFS
+26
Survey repeatability, days5
Active life, years-
space venicle dimensions, m x m -
space venicle mass, kg1250
The IRS space images include the data received by several Indian space vehicles. IRS-1C and IRS-1D operative space vehicles acting today are in the orbits from 1995 and 1997 accordingly.
The installed on the satellites equipment the earth surface survey with the spatial resolution of 5.8 m in panchromatic mode (PAN instrument) and simultaneous multispectral survey with the spatial resolution of 23, 70 and 188 m (LISS-3 and WiFS instruments).

Survey equipment technical characteristics

Survey equipment namePANLISS-3WiFS
Focal distance, m0.9820.34700.56
Main reflector diameter, cm---
Aperture ratio---
Field angle, deg---
Spectral ranges, micron0.5 - 0.750.52 - 0.59
0,62-0,68
0.77 - 0.86
1.55 - 1.70
0.62 - 0.68
0.77 - 0.86
Elements number in scale40966000
300 for SWIR
2048
Dynamic range, bit677
Ground resolution, m5,823/70188
Swath width, km70141/148810
message data rate, Mbit/sec84,942,442,4
Onboard memory volume, Gbit---
IRS space venicle visual production is distinguished for its high quality at low prices, that is why it gets the major distribution at the ERS products international market. Due to a distributor agreement with American GeoEye company conclusion, India became the space information one of the largest world suppliers, being inferior in the sells volumes only to the US and France companies.
The space images with resolution of 6 m, 23 m and 70 m received by IRS space venicle are designed for the agricultural monitoring, rational nature management, land cadastre, disaster prevention and their after-effects liquidation tasks solution.