Imaging modes are different SAR operation modes. Different modes are used depending on what is required, a better azimuth resolution or a longer swath.
SAR collections offer imagery that is captured in four primary imaging modes: spot, site, strip, and scan.
In the spot mode, the antenna beam is focused on a point for an extended period. The mode provides the highest azimuth resolution out of all modes.
The site mode can be viewed as a sliding variation of the spot mode. It is similar to spot, but instead of illuminating a fixed point on the ground, the angle is slowly varied to slide the illumination point along the ground. The mode provides a longer swath than the spot mode, but lower azimuth resolution.
In the strip mode, the center of the antenna beam is fixed in elevation and moves with the satellite. The result is a single continuous strip. The mode provides a longer swath than the site mode, but lower azimuth resolution.
In the scan mode, the antenna beam moves between sub-swaths to acquire adjacent coverages that are processed into one long and wide scene. Each sub-swath is illuminated by multiple pulses but for a shorter time than in the strip mode, resulting in lower azimuth resolution.
Collection | Spot | Site | Strip | Scan |
---|---|---|---|---|
Capella Space | Spotlight | Sliding Spotlight | Stripmap | |
ICEYE | Spot Fine Spot Spot Extended Area | Strip | Scan | |
KOMPSAT-5 | High Resolution Enhanced High Resolution Ultra High Resolution | Standard Enhanced Standard | Wide Swath Enhanced Wide Swath | |
TerraSAR-X | SpotLight High Resolution SpotLight High Resolution SpotLight 300 MHz | Staring SpotLight | StripMap | ScanSAR Wide ScanSAR |
Umbra | Spotlight |
Collection | Spot | Site | Strip | Scan |
---|---|---|---|---|
Capella Space | Spotlight | Sliding Spotlight | Stripmap |