I have two Landsat 8 satellite images from two different dates in may. When I import them in ArcGIS they slightly overlap but the pixel colours don't match making it hard to run an NDVI. I have been trying to run colour matching on the two datasets by creating a mosaic or raster catalogue but it doesn't work.
There are several factors that may be causing the effects you are seeing:
- You have not atmospherically corrected the Landsat images. Especially if the images were acquired at different time periods, you will notice differences in pixel values between the two.
- The images were acquired at different time periods leading to variation in variables such as sun angle and vegetation.
- Your software is not applying any color matching.
I suspect the issue relates to not correcting the images to bottom of atmosphere reflectance.