Swath
Also called: Swath width · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 11, Ch 6 "Introduction to Remote Sensing"
Meaning
The swath is the width of the strip of ground that a satellite sensor images in one pass. The sensor's angular field of view sets it. This is the angle across which the sensor can "see". A wide swath covers more ground in each pass, so the satellite can return to the same place sooner. A narrow swath usually comes with finer detail. This trade-off is why countries launch constellations, which are groups of satellites working together.
Example
The French SPOT satellite's HRV sensor has a 60 km swath, split into 20 m ground cells. Its pushbroom design needs one detector per cell, so it uses 60,000 ÷ 20 = 3,000 detectors in a line.
Don't confuse with
- Spatial resolution: the ground size of one pixel, such as 20 m. The swath is the width of the whole strip, such as 60 km.
Related concepts
- Sensor
- Photographic sensor
- Multispectral scanner
- Whiskbroom scanner
- Instantaneous field of view
- Pushbroom scanner
- Passive and active remote sensing
- Radar
- Synthetic aperture radar
- LiDAR