How do I download the free base station data from NGS?
The National Geodetic Survey (NGS) has a network of base stations across the United States. They provide their base station data free of charge to the public. 1. In PC-GPS the Batch Differential Processor can automatically download from the National Geodetic Survey CORS base station network. 2. You can also obtain the CORS Rinex data via non-ftp site through the world wide web. Please click the above “base station data” link, or use the following address (case-sensitive): http://www.ngs.noaa.gov/CORS/Data.html You will need to download the “RINEX 2 data” and also the “Global/Broadcast Ephemeris data” (under the non-site specific section) for the day and base station you need. After downloading and unzipping the data, you will see the file extensions: *.04o and *.04n. The file prefixes also need to match. The global ephemeris file has a generic name like: brdcxxx.04n. Please rename the file prefix to match the *.04o file. For example, if the *.04o file is named: fts11230.04o, then renam
