Proceedings Article | 8 November 2014
KEYWORDS: Synthetic aperture radar, Binary data, Doppler effect, Antennas, Tolerancing, Image resolution, Beam controllers, Telecommunications, Radar imaging, Associative arrays
Spaceborne Synthetic Aperture Radar (SAR), with "all weather", day or night imaging
capabilities, has been playing an important role in the domination of Earth observation. Spaceborne
high-resolution wide-swath SAR (HRWS-SAR) can quickly obtain wide range of the earth’s surface
information, which is of great significance to Earth mapping, geological exploration, vegetation and
biomass estimates, marine monitoring, target search, disaster relief, etc. As a result, spaceborne
HRWS-SAR has been gaining more and more attention. However, considering the restrictions on
pulse repetition frequency (PRF) and power-aperture product, space-based SAR imaging cannot
achieve high resolution and wide swath at the same time. Currently existing solutions mainly focus
on the antenna system hardware devices, such as MIMO, DBF; other signal-processing-bias
solutions, such as Mosaic imaging technology, have higher requirements of the antenna pointing or
beam control. These methods adopt more antenna elements or complex beam control method, which
greatly increased the demand for hardware performance, and the signal processing method become
more complicated as well. In order to relieve the pressure on the system hardware devices, this paper
presents a new orthogonal coded waveform method based on the theory of communication. By using
this method, the LFM signal is coded by the orthogonal codes to make the inter-pulse waveform
irrelevant, which ensures the azimuth sampling rate as well as a wide swath. Theoretically, this
method can alleviate the contradiction between PRF and high resolution wide swath imaging.
