envimodisndviremote sensing
I want to use TIMESAT software to analyse time series MODIS NDVI data. Firstly, I use MRT tool to mosaic,subset and project MODIS NDVI data and output data as GEOTIFF format, and save as ENVI standard using ENVI software. secondly, using TSM_imageview to display the image file, and the result is ok. then i use TSM_GUI to open list of image files, the problem is arising–"Error while evaluating uimenu Callback" .
so, if anyone knows the answer, please help me, thanks a lot!
You may take a look at "pyModis", a Free and Open Source Python library to work with MODIS data. It can bulk-download, mosaik and reproject:
If you look at the product page at LPDAAC, under Layers there is a table that lists each of the bands in the dataset and their characteristics.
For the NDVI layer, it is a 16-bit signed integer with a fill value of -3000, and a valid range from -2000 to 10000. However, there is also a scale factor of 0.0001, or 1/10,000. This means that a value of 10000 in the raster should be multiplied by 0.0001 in order to achieve the actual data value. In ENVI, you should try using Interactive Stretching and rescale the raster to go from 0 to 10000. If you need more pointers on using ENVI, let me know and I can take some screenshots.
It seems odd that NASA would implement this weird scale factor, but it makes sense when you think about it. A 32-bit floating point value that stored the NDVI value verbatim would take up twice as much space before compression versus this integer format, and it would suffer from the precision issues inherent in floating point values. By storing the value as a scaled integer, the file stays small and the precision is retained.
Let me know if you have any other questions about MOD13Q1. I have a good amount of experience using this data set for time series analyses.
Best Answer
It seems, on the first line of image files' list there is no total number of those files. Or there is a wrong number.
Please, check the list of image files.