Q1) I need to know how the scale factor should be used. (I am using ArcMap 10.1.) Should I directly multiply with the band 1 and band 2 images using raster calculator ? another thing that when m trying to open those image they are in HDF format and the coordinate system is undefined .
Q2) Another thing that when I am trying to open those image they are in HDF format and the coordinate system is undefined unknown datum based upon the custom spheroidal projection, and Datum: not specified.
so how could i specify the spatial reference to UTM zone?
Dear Sumit,
It is well know problem of MODIS products. My suggestion is: you use ERDAS imagine software. Import hdf data to image in this where the datum and projection system will not be a problem. after importing your hdf into .img you can open it in any software. the UTM zone can be defined based on you area where you are carrying you study.
Thank you, Dharmendra Singh Sir for your suggestion. I would try it anyhow. But I have only ARCGIS10.1 and ENVI 5.1 thus i want to know is there any way to it in these software
You don't need proprietary software to deal with MODIS.
I use to handle MODIS using R only and particularly MOD09 products. You need GDAL library (OSGeo4W), R software, raster and GdalUtils packages.
To answer to your questions,
Yes, you just multiply the DN by 0.0001.
MODIS Projection is a sinusoidal. The proj4 string is '+proj=sinu +lon_0=0 +x_0=0 +y_0=0 +a=6371007.181 +b=6371007.181 +units=m +no_defs'
You can deal with MODIS hdf with QGIS. (a link bellow showing how).
https://pvanb.wordpress.com/2012/11/07/opening-modis-tiles-in-qgis/
http://www.khufkens.com/2016/04/20/modis-hdf-data-extraction-in-r/
You may also have a look at this "R" package for automatic preprocssing of MODIS land products.It deals with download, reprojection and extraction of layers of interest.
https://www.researchgate.net/publication/309734109_MODIStsp_-_v130
Code MODIStsp - v1.3.7
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