Pushbroom scanner
Also called: Along-track scanner · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 11, Ch 6 "Introduction to Remote Sensing"
Meaning
A pushbroom scanner has a straight line of detectors, one for each ground cell across the swath. The swath is the width of the ground strip imaged in one pass. The scanner records a whole line at once. As the satellite moves forward, line after line builds up the image, like a broom pushed along a floor. There is no moving mirror. The number of detectors equals the swath width divided by the cell size.
Example
France's SPOT HRV sensor has a 60 km swath and 20 m cells, so it needs 60,000 ÷ 20 = 3,000 detectors. India's LISS cameras on IRS satellites are also pushbroom sensors.
Don't confuse with
- Whiskbroom scanner: this uses a rotating mirror and a single detector. It sweeps sideways across 90° to 120°, recording one cell at a time.
Related concepts
- Sensor
- Photographic sensor
- Multispectral scanner
- Swath
- Whiskbroom scanner
- Instantaneous field of view
- Passive and active remote sensing
- Radar
- Synthetic aperture radar
- LiDAR