Editing a Rinex File from a PM3

Maybe...probably...

It's unlikley that the data files have the wrong date (possible I suppose), and more likely that you are reading the file data incorrectly.

A RINEX file collected in October of this year should have observation records that start with lines like this one:

10 10 18 14 1 30.0000000 0 8G11G14G16G20G23G30G31G32

Post the header data (first 20-30 lines), and a couple of observation records, and let us take a look.

Loyal

Always do a GPS reset prior to using your PM3s. First turn them on and let them run for a few minutes then do a GPS reset. If the hourglass comes up for several seconds then you know it's working. If the hourglass flashes on the screen just for an instant then you didn't wait long enough before doing the reset.

Loyal and Dave,

Thanks for responding. I must have been working late when I imported the data and created the project.

I just went back, and re-downloaded the data, and it was actually the two files from the Hipers that had the wrong date. I must have downloaded the wrong files.

Thanks,
Jimmy

P.S. I looked at the segment of the file that you posted, and I have a better understanding of how to look for bad data.

Editing a Rinex File

Thanks to Loyal I was able to recover a couple files that actually had some kind of date burp in them. 4700 receivers did some weirdness when it passed UTC turnover. Put a couple of EPOCHS in with a date about week earlier. OPUS didn't like it!

Kinda weird. With the date fixed they processed just fine.

Also figured out that if you have less than 48 hrs data but it is in 3 different UTC days, OPUS rejects it. I had a couple files that where about 26 hours data and they wouldn't go. Started up just before UTC turnover so they included data from 3 different UTC days.

Just the quirks of it all!

Jimmy,
I have a little experience recovering from the situation you described if it is a PM3 file with a bad date.

The easiest way I have found is to go into your project folder in My Computer or Windows Explorer and find the raw files as they came off the receivers. The raw file will have a lower case "p" in as the leading character.

I have had success with the date issue by merely changing the extension of that file to the correct Julian date. That "fixes" the date on the file when you bring it into the pose processing software. At least, this works in GNSS Solutions. I don't know for certain with the process in Ashtech Solutions.

I learned this method with a customer's receivers that frequently give bad dates on files. I think they just start the session before the receiver has solved its position.

Jerry,

Thanks for the response. I will print this out and put it in my PM3 notebook.

How is Daniel doing?

Thanks again,
Jimmy