LDOPE QA Tools

Land Data Operational Product Evaluation (LDOPE) is performed by the VIIRS Land Product Quality Assessment team who have developed a set of tools for use with the VIIRS land products.

In addition to the ability to work with the VIIRS Land products, the Land Team also requires the ability to work with data products from other heritage instruments like MODIS to facilitate the comparison of products from multiple instruments.

Current commercial off the shelf (COTS) software tools available for image processing and spatial data analysis do not adequately support many specifics of the VIIRS and MODIS Land products, which may result in incorrect product use and thus results. The Land Product Quality Assessment team developed a set of tools for use in the quality assessment of MODIS data for the science teams and other data users since the launch of Terra and Aqua. These tools have been updated for use in the assessment of VIIRS algorithms and products generated using MODIS proxy data prior to launch, and for processing on-orbit data since the launch of the NPP in Nov 2011.

The tools are written in C and can run in command line mode or called from scripts and other packages. They are invoked using a UNIX-like command and argument syntax. A subset of these tools are integrated to ENVI using the Graphical User Interface (GUI) library developed by Exelis.

MODIS/VIIRS Reprojection Tool

LDOPE team has been using different projection tools that have been developed in-house,to reproject MODIS/VIIRS Land data products in both HDF4 and HDF5/NetCDF4 data formats. These reprojection tools, developed in C, can handle all MODIS/VIIRS Land data products, including L3/L4 gridded Sinusoidal 10-degree tiled data products as well as swath based L1B and L2 products. These tools are now being distributed to the user community as part of this package, with the addition of a Python based simple wrapper interface to make it easy for general users to invoke and run these core C-based reprojection utilities.