Change detection is the method used to reveal the changes between satellite images of the same area taken at different time periods.
While the images to be analyzed should have the same sensor and band, their resolutions and sizes do not have to be the same. The operation is performed in common areas of the images.
Change is used for relative differences in the reflection value. If the pixel value of the first raster data input in the operation is greater than the second raster pixel value; this change is a (+) change, otherwise, i.e. the first raster data pixel value is smaller than the second raster pixel value; the change is called a (-) change. If there is no difference between the pixel values, it means that there was no change in those areas.
Data input of the change detection should have 8-bit gray, 8 bit color, 16 bit and 24 bit color radiometric resolution. If the final data obtained after a different analysis is required to be used for this analysis and if its radiometric resolution is not appropriate, other raster editing operations (change depth (?), convert to gray (?)) can be used.