In order to use remotely sensed data, the user has to understand the characteristics of the system being used. The most important system characteristic the user has to understand is resolution. The application will determine what kind of resolution is necessary. Once the desired resolution is known, the cartographer can decide the system that would best fit the application. Resolution is measured in three ways, spatial, spectral, radiometricand temporal.
Spatial resolution is the amount of surface detail a system can detect.
Spectral resolution is the the number of frequency bands and the width of those bands. Radiometric resolution is the sensitivity of detectors to record the variations of reflectance. Temporal resolution is the age of the data and the frequency the data can be collected. Photographic systems have a lens, shutter and aperature that creates images with high spatial resolution. Photographic systems can be simple frame camaras, multiframe camaras or strip camaras.