4 - Central Institute of Brackishwater Aquaculture

Natlonal Workshop-cum-Traln~ng on Blolnfonnatia and Information Management in Aquaculture
Figure 5. A remote sensing image showing pixels with intensity value and
location address
2.1.2 Resolution of Remote Sensing Data
The information acquired through remote sensing imaging is resolution
dependent. Several types of resolutions are considered in remote sensing studies
those are (i) Spatial resolution (ii) Spectral resolution (iii) radiometric resolution
and (iv) temporal resolution.
Spatial resolution refers to the size of the smallest object that can be resolved
on the ground. In other words, it is the minimum distance between two objects
that a sensor can record distinctly. In a digital image, the resolution is limited by
the pixel size, i.e, the smallest resolvable object cannot be smaller than the pixel
size. The intrinsic resolution of an imaging system is determined primarily by the
instantaneous field of view (IFOV) of the sensor, which is a measure of the
ground area viewed by a single detector element in a given instant in time.
However, an IFOV value is not in all cases a true indication of the size of the
smallest object that can be detected. An object sufficient contrast with respect to
its background can change the overall radiance of the given pixel so that the
object becomes detectable. Spatial resolution of a remote sensing system must
be appropriate if one is to discern and analyze the phenomenon of interest. To
move from detection to identification, the spatial resolution must improve by