Instantaneous field of view
Also called: IFOV · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 11, Ch 6 "Introduction to Remote Sensing"
Meaning
The instantaneous field of view (IFOV) is the small patch of ground that a scanner's detector sees at one moment. Its size fixes the size of the ground cell, or pixel, so it sets spatial resolution. A smaller IFOV means smaller pixels and finer detail. In a whiskbroom scanner, a rotating mirror sweeps the detector sideways across 90° to 120°. That full sweep is the total field of view (TFOV).
Example
Landsat MSS, flown by the USA from 1972, swept its view across the ground with a mirror. Its IFOV gave ground cells of about 80 m. So any feature smaller than about 80 m, such as a single village pond, merged into its surroundings.
Don't confuse with
- Total field of view (TFOV): this is the whole width the scanner sweeps across. The IFOV is the tiny part seen at one instant.
- Swath: this is the width of the ground strip imaged in one pass, not the size of one cell.
Related concepts
- Sensor
- Photographic sensor
- Multispectral scanner
- Swath
- Whiskbroom scanner
- Pushbroom scanner
- Passive and active remote sensing
- Radar
- Synthetic aperture radar
- LiDAR