Bad date on GPS log file

Give It A Few Minutes To Warm Up

Before logging data.

You probably want to clear everything out and give it a fesh start, maybe even reload the programs.

If you are going to do short occupations, as a minimum run it the day before to get it current.

OPUS reads the observation data and can sometimes ignore errors in filenames etc. Stop time in the header is totally uneccessary. Start time used to be, but I recall a few unedited start times got properly processed. I once edited down RINEX files and found only 4 required lines in the header for a valid OPUS file.

Paul in PA

CC, I don't think you need to make it perfect, but here is what I do, as it happen all the time to me on an older receiver with a bad internal battery...

Open the rinex in wordpad, and scroll pass the header. You will see the GPS data, prefixed by 1988. I select all of that data, and just delete it. There is usually about 15 seconds of it, or 1 to 2 complete observation sets from the sats. Delete all of the data up until you get to the current date. Look at that date, and then scroll back up to the header, and just edit the beginning time of the observation date. Change all of the sections, year, month, day, time, and seconds.
That’s it, save it and it will work fine.

Let the receiver run longer before starting the log file. The receiver's default date is 1988 but will update to the current date/time after the receiver has initialized.

I'll give the edit a try and tell my guys to let her warm up a bit before logging.

Thanks guys!

Dan nailed it. When you clean out the files, your unit needs to run for a while to download the almanac files. If you start logging before this happens then you will get the 1988 date. This is explained somewhere in the operators manual and I think they suggest letting it run for 15 minutes prior to logging data. Again though this is only if you have cleaned out ALL the files, ie almanac or reset the unit.

Recommended Start Up Procedure

As soon as antenna is on the pole and connected to the receiver, turn the receiver on. Since I use fixed height rods with 3 legged bopods this may be at my vehicle and not at the point to be occupied. Quite often I enter my job and point name at the vehicle also, then walk to the point carrying the whole setup upright in one hand. Once set up and plumb I recheck my skyview screen and if I am satisfied I tell it to start collecting. For those receivers that start collecting data as soon a certain parameters are met, I close out the first file, starting a new one. Usually but not always I delete that short file before walking away, saving me the job at the end of the day or before I download. By doing it immediately when there is no other file for that day, I avoid the possibility of dumping a file I need. On my older receivers that are slower to gather satellites I sometimes watch and wait till I am satisfied. I am very concious that an extra 5 minutes in the field can save me considerably more time in the office. That is not necessarily just the time it takes to edit a file, but lost time starts when you submit to OPUS, wait for an abort rather than a solution, then start looking for reasons.

If your field guys don't download and process themselves it is harder for them to appreciate doing it right.

Paul in PA

SOP, let the static units "settle down". I usually give 'em 5 minutes.

:coffee: