Data Handling System for IRS

Abstract

The three axis stabilized Indian Remote Sensing Satellite will image the earth from a 904 Km polar - sun synchronous orbit. The payload is a set of CCD cameras which collect data in four bands visible and near infra-red region. This payload data from two cameras, each at 10.4 megabits per sec is transmitted in a balanced QPSK in X Band. The payload data before transmission is formatted by adopting Major and Minor frame synchronizing codes. The formatted two streams of data are differentially encoded to take care of 4-phase ambiguity due to QPSK transmission. This paper describes the design and development aspects related to such a Data Handling System. It also highlights the environmental qualification tests that were carried out to meet the requirement of three years operational life of the satellite.