I want to apply spectral mixture analysis method for estimating impervious surface. So, I have downloaded a Landsat Image from USGS earth explorer. When I add a shapefile and the image in ArcGIS, I find that the Image show right location.
So, Can I say the landsat image is geometrically corrected? If Landsat image are not geometrically correct, then how can I make the image geometrically correct?
What is orthorectification for Landsat Image?
You don't need to correct the images. The USGS/NASA already made this for you. I mean, the images of Landsat-8 that were downloaded by the site of USGS. If the name of the image has "L1T" means that it has already been corrected using ground control points (GCPs) and a digital elevation model (DEM).
Hi SUshanta,
check this RG thread, the answer that Forrest Robert Stevens gives is what you need!
https://www.researchgate.net/post/Do_I_need_to_gerometrically_correct_landsat_images_L1T
Have a nice day,
Nic
if the geometrical corrected means to georefernce, then landsat images are georeference downloaded from usgs.
just check the link below
http://landsat.usgs.gov/Landsat_Processing_Details.php
What about orthorectification for Landsat, Muhammad Usman? Can you give me any idea about that?
When you have an aerial photo of an area in the center of it can be seen perpendicular to the surface, this does not happen with the ends of the same picture so to rectify these errors became orthorectification
Landsat images need not be rectified as they are not data obtained from a flight plan (such as aerial photos ), but the satellites. Of course, the clouds is higher in satellite images on aerial photographs
ortho rectification is necessary for aerial photo, which are captured on low altitudes. That why we adjust elevation in these photos by doing ortho rectifications,
Landsat images may not need to do ortho rectifications,
if you download it from USGS. To check the elevation prespective of your study area, try to download DEM from USGS and check it.
Thank you for your guidelines. So, georeference and orthorectification has no significance for Landsat. Would you please tell me what steps should I follow for geometric correction of landsat image?
you can follow below link:
http://www.gis.usu.edu/~doug/rs5750/lectures/L7_Geometriccorr.pdf
http://landsat.usgs.gov/geometry.php
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if you are using landsat images downloaded from USGS, there is not need of rectification and ortho rectifications please.
I you got some unrectify images of landsat then may use Mehebub Sahana provided links
You don't need to correct the images. The USGS/NASA already made this for you. I mean, the images of Landsat-8 that were downloaded by the site of USGS. If the name of the image has "L1T" means that it has already been corrected using ground control points (GCPs) and a digital elevation model (DEM).
Thanks for your reply Roberto Filgueiras. What about another Landsat Images including Landsat 1,2,3,4,5,7?
Recently I downloaded reflectance images (Landsat 5) of the USGS and they were already been corrected.
@Paulo
Do they correct the for reflectance and then upload.
I believe U have have got corrected image with DN's.
Plz specify, if I am wrong.
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