Radiometric Resolution

Radiometric resolution is the radio-frequency sensitivity of a remote sensing platform. Usually captured from airplanes and space-based satellites, remotely sensed data provide a uniform view of geographic space. This view of Earth can extend beyond the visible range of wavelengths.

Remote sensors have four resolutions: spatial, temporal, spectral, and radiometric. Commonly referred to as the pixel bit depth of a sensor, radiometric resolution is the sensitivity to reflected radiation across the spectral resolution of the sensor. Consumer digital cameras, for instance, detect visible spectrum light using a CCD or CMOS sensor with 8 bits of radiometric resolution for red, green, and blue bands. This translates to 256 possible shades of each color band for an aggregate 24 bits of radiometric resolution, resulting in more than 16 million different colors for each pixel. The Multispectral Scanner (MSS) on Landsats 1–3 had a radiometric resolution of 6 bits for 64 levels for each of the four bands: red, green, blue, and near-infrared. The Landsat Data Continuity Mission (LDCM) proposal specifies a new array of sensors with 8 bits of radiometric resolution for each of the nine bands of radiation. Radiometric resolution presents a trade-off as with spatial resolution due to data collection and transmission limitations. Increasing the radiometric resolution directly increases the volume of data transmitted. Furthermore, increasing the radiometric resolution has been shown to mostly increase the noise versus the desired signal.