Contents
Which is the best method for topographic correction?
Both SRTM and ASTER DEMs are suitable for topographic correction of Landsat imagery whenever higher resolution DEM are not available ( Gao and Zhang, 2009b ). Once the illumination angle is known, the removal of topographic shadows may be based on different methods.
How is topographic normalization used in time series?
Topographic normalization is one of the key steps to create consistent and radiometricly stable multi-temporal time series, since terrain shadows change throughout time. This paper aims to evaluate different methods for topographic correction of Landsat TM-ETM+ data.
Where can I find the regression with SAS book?
You can access this data file over the web by clicking on elemapi.sas7bdat, or by visiting the Regression with SAS page where you can download all of the data files used in all of the chapters of this book.
When do you need to use topographic shade correction?
Within the radiometric normalization of multi-temporal images, the correction of topographic shade is especially critical when the target area has rough terrain, since illumination conditions change along with seasonal sun zenith angle.
Is the Minnaert constant a perfect Lambertian reflector?
The factor l is the Minnaert constant, modeling the non-lambertian behavior for every band and land cover separately. The Minnaert constant has a value between 0 and 1. When the Minnaert constant l = 1 than the surface is considered as a perfect lambertian reflector. In practice, this factor is estimated by linearizing equation (7).
Are there any errors in my raster DEM?
My DEM (ASTER) have one small error where the elevation is about 300m below the actual elevation. It should be a hill, and not a hole… SRTM 4.1 is good, but has other errors (the hill is very steep and small, so SRTM “ignores” it (<90m).
How to manually correct raster DEM in QGIS?
‘output.csv’ will be a space delimited text file containing the xyz triplets. Next, load ‘output.csv’ into a plain text editor, search to find the coordinates and change their z-values as required. Save the file, then convert it to a DEM TIF using gdal_translate:
https://www.youtube.com/watch?v=RPMemRR1UPs