ScanSAR

ScanSAR is a radar imaging mode used in synthetic aperture radar (SAR) systems to achieve wide-area coverage. It works by dividing the ground track into several adjacent sub-swaths and rapidly switching the radar’s sensing across them in successive bursts during a single pass.

Each sub-swath is imaged with standard SAR processing, and the resulting data are mosaicked to form a single wide swath image. This provides greater areal coverage at the expense of coarser azimuth resolution.

Compared with stripmap modes, ScanSAR reduces data density per unit area and can introduce radiometric and geometric variations between bursts, as well as edge effects and Doppler centroid shifts between sub-swaths. These characteristics require careful processing and calibration to produce consistent imagery.

ScanSAR is widely used for rapid mapping of large regions, disaster response, monitoring deforestation, agriculture, and land cover change, where frequent revisits are valuable and moderate resolution is acceptable. Its wide swath configurations enable quicker assessments over expansive areas compared with higher-resolution SAR modes.

Examples of platforms that implement ScanSAR include various satellites equipped with SAR sensors, such as those from RADARSAT and Envisat missions, which offer wide or jumbo ScanSAR configurations to balance coverage, resolution, and data rate.