ĭue to system tradeoffs related to data volume and signal-to-noise ratio (SNR) limitations, remote sensing images tend to have either a high spatial resolution and low spectral resolution or vice versa.
The temporal characteristic is helpful in monitoring land use changes. Satellite-based sensors, based on their orbit, may dwell continuously on an area or revisit the same area every few days. The temporal resolution refers to the time elapsed between consecutive images of the same ground location taken by the sensor. In other words, a higher radiometric resolution allows for simultaneous observation of high and low contrast objects in the scene.
The Landsat 7 sensor records 8-bit images thus it can measure 256 unique grey values of the reflected energy while Ikonos-2 has an 11-bit radiometric resolution (2048 grey values). A larger dynamic range for a sensor results in more details being discernible in the image. The radiometric resolution refers to the dynamic range or the total number of discrete signals of particular strengths that the sensor can record. Spatial resolution refers to the smallest features in the scene that can be separated (resolved). High spectral resolution is characterised by a narrow bandwidth (e.g., 10 nm). Spectral resolution refers to the bandwidth and the sampling rate over which the sensor gathers information about the scene. Remote sensing images are characterised by their spectral, spatial, radiometric, and temporal resolutions. King, in Image Fusion, 2008 16.1.2 Characteristics of remote sensing imagery