txt metadata file to the metadata in the GeoTIFF or NetCDF, please see Appendix 1 at the bottom of this article. If you would like to add the time and date information from the.
For files prior to 01 October 2013: GeoTIFF The coordinates used in the -a_ullr flag are slightly different for files before and after 01 October 2013. Issue one of the gdal_translate commands listed below. Ensure your working directory contains both the. Save the header file using the exact same file name as the data file you are converting, but with a.
Using a text editor, create an ENVI header file (.hdr) with the following information:ģ. Unzip and untar all data if you have not already: 'gunzip *.gz' should do the trick if you work in a linux environment. The instructions for the masked (files beginning with 'us') and unmasked (files beginning with 'zz') files are slightly different, so please find separate instructions below for the masked and unmasked files: Masked filesġ. This should return the version of your installation. A good way to test whether or not you have installed GDAL correctly is to issue the 'gdalinfo -version' command. Addtional details on downloading GDAL can be found on the GDAL website ( ). There are additional package managers available for Linux users. NSIDC User Services is not able to provide support for installing GDAL, but we have found using a package manager such as MacPorts ( ) simplifies the installation process on a Mac. You will first need to have GDAL installed on your system before proceeding on to the following steps. Therefore, please note that the date of the file(s) you wish to convert will determine which set of coordinates you use in this tutorial, examples for files before and after 01 October 2013 are provided. The resulting shift is minute, and on the order of 1/4 of a 1km grid cell. On this date, the data provider, National Operational Hydrologic Remote Sensing Center (NOHRSC) slightly changed the center coordinates of the grid to align with an integer value of latitude and longitude.
This article describes the use of Geospatial Data Abstraction Library (GDAL) tools for converting SNODAS binary files to NetCDF or GeoTIFF.īefore working through the rest of this tutorial, we would like to make you aware of a small spatial data shift that occurs on 01 October 2013 in the SNODAS period of record.