Abstract
A synthetic aperture radar (SAR) is one of the promising microwave sensors for earth observation. The National Space Devolopment Agency of Japan (NASDA) started the phase A study (preliminaly analysis) in FY1978, recognizing the importance of active microwave remote-sensing.
The research and development proceeded to phase B/C (definition/design) after the heated discussion on the Earth Resources Satellite-1 (ERS-1) at the Space Activities Comission in August 1980. Recently the technically critical components have been developed and the basic tests completed. At present, the final stage of the phase is going on. In this paper, the policy, the goals and the schedule of the research and development on SAR are described. The major test results of the following critical technologies are also introduced.
1. to keep the antenna pannels flat. in the space environment,
2. to obtain high power by solid-state amplifiers,
3. to get a large time-bandwidth-product (TBP) for pulse extention,
4. to achieve high frequency stability with crystal oscillator.
