How to do geometric Correction in erdas?
How to do geometric Correction in erdas?
How to do geometric Correction in erdas?
Select RASTER > Geometric Correction from the viewer’s menu bar and Polynomial from the dialog box….The basic proceedure will be to:
- display files.
- start Geometric Correction tool.
- record Geometric (ground) Control Points (GCPs)
- resample the image.
- verify.
What is geometric correction in remote sensing?
Geometric correction (sometimes abbreviated to geocorrection) is the process of transforming the X and Y dimensions of a remotely sensed image, so that spatial distortions in the original image are eliminated or minimised and the output X and Y dimensions correspond to a chosen geographic reference system.
What is geometric correction used for?
Geometric correction corrects a satellite image for these displacements, and ensures that pixels/features in the image are in their proper and exact position on the earth’s surface. Image levels 3A and 3B do not typically require this step as they often represent the highest possible level of geometric correction.
What is topographic correction?
topographic correction (terrain correction) A correction applied to observed geophysical values to remove the effects of topography.
What is absolute atmospheric correction?
Absolute correction take into account the atmospheric conditions at the same time of satellite overpass and aims to acquire absolute reflectances based on the acquisition time of the image. As output, FLAASH produces a surface reflectance (Rsup) image.
What is DOS atmospheric correction?
DOS is ” Dark Object Subtraction” method for atmospheric correction, 1-4 represents various sets of input parameters like atmospheric transmittance (Tau) used. DOS is one of the most common used atmospheric correction method.
What is the difference between radiometric correction and geometric correction?
Radiometric correction is to avoid radiometric errors or distortions, while geometric correction is to remove geometric distortion. Therefore, in order to obtain the real irradiance or reflectance, those radiometric distortions must be corrected.
How do you perform atmospheric correction?
Dark object subtraction, radiative transfer models, and atmospheric modeling are common techniques used to correct for atmospheric disturbances. Some satellite data are delivered as surface reflectance such as the Landsat Surface Reflectance products available on the USGS Earth Explorer.