How long is an SSF file valid ?

Question

If I collect some GPS data (utilizing GPScorrect) then I can still deferentially correct the data a few days later usung GPS Analyst in Arc 10.  Now can I still run that same process a week later, or a month later?  Basically how far back in time can GPS Analyst reach?  I ask since someone from my office may go on a site visit to collect GPS data, and not come back to the office and have access to GPS Analyst for a few weeks.

On a side note if I go out and collect some data on Monday, then go back out on Tuesday and collect some more data, will my GPScorrect.ssf file be overwritten with the Tuesday data?

ericbock · Accepted Answer

You can collect data on a GPScorrect.ssf file for 7 days.  After the 7th day the software will automatically create a new GPScorrect_1.ssf, but this may cause problems when checking the data back in.  I recommend not to collect data for longer than 7 days on one checkout file.  The way I look at it is how many days of data can you afford to loose if something goes wrong?  For me it is none, so i recommend checking in the data everyday.  Store your data on an SD card as well!

You can go back and process the data whenever you like.  NGS keeps an archive of Base station data.

CORS website http://www.ngs.noaa.gov/CORS/

CORS Data Availability and Retention Policy

RINEX observation, meteorological, navigation and TEQC summary files:
Hourly files are only kept for 2 days
Daily files are kept permanently.  Two daily observation files are kept for every site: 
a Hatanaka and UNIX compressed version which contains data decimated to 30 seconds and 
a second gnuzipped (gzip) version which contains data at the original sampling rate that the site is operated.

Hope this helps, ericb