MOOC4Land - A Massive Open Online Course on Remote Sensing for Land Applications
Remote Sensing - The Basics5 Topics|1 Quiz
Sources of Remote Sensing Data2 Topics|1 Quiz
Resolutions - Dimensions of Remote Sensing4 Topics|1 Quiz
Processing Fundamentals of Remote Sensing Imagery2 Topics|1 Quiz
Essential Image Analysis Techniques5 Topics|1 Quiz
Data Processing Platforms3 Topics
Last but not least, we will introduce you to the radiometric resolution. While the spectral resolution decides how much of the EM spectrum a sensors ‘sees’, the radiometric domain defines the amount of gradients that are measured.
What is radiometric resolution?
The radiometric domain is also related to as ‘color depth’ and is defined as the sensitivity to the magnitude of the EM energy. Thus, it characterizes, how finely a given sensor can receive and divide the radiance between the different bands. Explore the animation on the right to the difference between lower and higher radiometric at comparable spatial resolution. A greater resolution increases the range of intensities that a sensor can distinguish.
How the spectral domain is represented
Typically, the radiometric resolution is expressed in bits. The bit count is used for characterizing numbers in the binary data format and each bit relates to an exponent of power 2 (e.g. 4 bit = 24, 0-15), which is the number of grey values that are being recorded. This value is given for each band. Former remote sensing data sets were recorded (mostly) in 8-bit format. The latest optical sensors such as Landsat 8 & Sentinel-2 (L2A) come with 12-bit data products. An image channel with 12-bit data is recording 212 (4,096) grey level values or shades of that given wavelength. Consequently, the level of detail in remotely sensed data strongly depends on the bit depth, in which the data was recorded.