Characteristics of Geosynchronous Synthetic Aperture Radar (GEO SAR), including ground velocity, integration time, azimuth resolution and other factors, are investigated. And the relationship between them and orbital elements is analyzed. Then a subaperture mode based on yawing steering which is more suitable for GEO SAR is proposed. By applying this mode reduction of range migration is obvious, and system parameters of L-band GEO SAR are designed,
including the antenna size, the pulse width, the peak transmitted power, and pulse repetition frequency. Finally a modified Range Doppler (RD) algorithm based on quintic polynomial and a Chirp Scaling (CS) algorithm based on spectrum mosaic are advanced. Point target simulation is implemented and the azimuth resolution is assessed according to the rule of being able to distinguish adjacent targets. It is demonstrated that the proposed image formation algorithms can provide a spatial resolution better than 15m.
This paper presents a novel algorithm based on curve surface mosaic, to create a full view spherical panorama from
image sequences. The work is concentrated on sphere projection, blank holes elimination, global illumination alignment
and curve patch stitching. When in projection, a special longitude-latitude-curve-patch is proposed to describe the
projective image to avoid info losing and wrinkle unwrapping that occurred in some traditional methods. Then a way of
"inverse-interpolation" is applied to eliminate projective blank holes caused by discrete calculation. To achieve global
illumination alignment for patches with great illumination differences, a novel method of "dispersing cumulative error"
is presented. It overcomes the shortcoming of traditional ways that are only for neighboring illumination alignment. The
final stitching of curve patches is accomplished by using a matching method based on image feature, and a smooth
seamless spherical panorama is gained. The whole algorithm runs automatically, which has high performance in
illumination alignment and spherical mosaic. It is valuable in practical application.