subswath

Subswath is a subdivision of a sensor’s ground swath. It is commonly used in radar and sonar imaging to describe a portion of the area imaged during a single pass or ping. In wide-swath systems, the full ground swath is divided into several subswaths to manage data volume, processing load, and variation in illumination geometry. Each subswath corresponds to a contiguous range interval or angular sector, and may be treated independently in initial processing steps, including radiometric calibration, geometric corrections, and speckle filtering, before the subswaths are mosaicked into a single continuous scene.

In synthetic aperture radar (SAR) and related imaging, subswath processing helps accommodate large incidence-angle variations across the swath, which can affect radiometric response and geometric accuracy. Subswath boundaries are potential sources of seams, requiring normalization and blending to ensure continuity.

In marine and hydrographic applications, multibeam sonar systems also use the term subswath to describe the subset of beams that together cover part of the seabed cross-section; multiple subswaths are combined to yield a full depth and backscatter map.

Key considerations include the sensor geometry, beam/antenna pattern, and the need to maintain consistent radiometric and geometric properties across subswaths. The term is largely empirical and workflow-specific, rather than tied to a single formal standard.