# Presentation: 712697

## NSIDC's ordering interfaces provide tools to simplify identification of  granules and to create subsets of granules. Browse images (online reduced resolution images) allow users to view data prior to ordering through the EDG and Data Pool.  The HDF Subsetting Appliance (HSA), available through the EDG, gives users options to subset data spatially, temporally, and by parameter. The HDF to GeoTIFF converter (HEG), available through the Data Pool or as a standalone utility, provides options to stitch, subset, reproject and reformat certain products. 

- NSIDC's ordering interfaces provide tools to simplify identification of  granules and to create subsets of granules. Browse images (online reduced resolution images) allow users to view data prior to ordering through the EDG and Data Pool.  The HDF Subsetting Appliance (HSA), available through the EDG, gives users options to subset data spatially, temporally, and by parameter. The HDF to GeoTIFF converter (HEG), available through the Data Pool or as a standalone utility, provides options to stitch, subset, reproject and reformat certain products.
- The MODIS Swath-to-Grid Toolbox (MS2GT), developed at NSIDC, is a set of software tools that reads MODIS swath HDF-EOS data files and produces flat binary files of gridded data in a variety of map projections.  NSIDC also offers many other options for converting the MODIS HDF-EOS format to binary or ASCII formats.  For more information on these, please see our HDF-EOS tools page at _[http://nsidc.org/data/hdfeos](http://nsidc.org/data/hdfeos)_.

- MODIS Collection 5 (V005), planned to start in April 2005, will include several improvements to existing snow and sea ice products for Terra and Aqua instruments.  The level 2 snow products will incorporate a revised cloud algorithm and a new fractional snow algorithm.  The level 3 gridded daily snow products will also include fractional snow cover.  The level 2 and level 3 sea ice products will be modified to eliminate sea ice determined by ice surface temperature.  New products will include gridded daily snow products in a polar projection, as well as monthly snow and sea ice products.  These additions will be valuable for polar research and global modeling using cryospheric data.

**Viewing Snow Cover Over Colorado Using MODIS Tools**

- In November 2003, Terra data were reprocessed to Collection 4 (V004).  The MOD10_L2 files now have two separate snow cover masks, one incorporating the original cloud mask, and another using a less cloud-conservative mask.  A sinusoidal grid projection replaces integerized sinusoidal (ISIN) grid projection in MOD10A1 and MOD10A2.  The MOD10A1 data granules after 14 September 2003 include a “Snow Albedo” data array.  The fractional snow cover in MOD10C1 now ranges from 0 – 100%, and the structural metadata (StructMetadata.0)  has been corrected from 24 July 2002 onward.  All of the sea ice products now have a threshold change from 277 K to 281 K in the thermal mask.
- In July 2004, all Aqua products were reprocessed to V004.  This collection includes the same properties as Terra V004, except MOD29P1N does not have a counterpart in Aqua V004.   The MYD10A1 granules after 4 July 2002 include a “Snow Albedo” data array.  In addition, all Aqua V004 snow and ice granules use MODIS band 7 instead of band 6, due to the large number of malfunctioning detectors in band 6. And due to increasingly erroneous snow detection using the NDSI/NDVI method with band 7 data, the NDSI/NDVI test is disabled.