Land Surveyor

I'm brand new to post processing using OPUS or any other post processing method.  A couple of days ago I collected 5 points, each for 20 minutes and uploaded them to OPUS.  All point were collected with the same setting on my data collector.  Four of the points came back with good results.  One of the points didn't process and I received the following error from OPUS

The file Base_3 seems to have a collection interval of 14 seconds!brThe collection interval must be 1,2,3,5,10,15 or 30 seconds to be processed by OPUS.            

1. I'm wandering why this happened and if I can edit the TPS file to possibly remove the data point that is causing the problem??

2.  With regard to the four points that were processed, can anyone elaborate on the quality of the data based on following typical results?

             OBS USED:     91%

             QUALITY IND.      13.47/ 2.56

             NORMALIZED RMS:          0.356



You need to be a member of Land Surveyors United - Surveying Community & Forums to add thoughts!

Join Land Surveyors United - Surveying Community & Forums

Votes: 0
Email me when people reply –


  • Bill,

    The OPUS service will only process sessions with the prescribed recording interval.  Imagine if you where trying to use a base/rover setup with the base set a 5 second update and the rover at a 12 second update.  They would only sync once every 60 seconds.  Your RMS error is a direct result of the very low number of synchronized readings between your receivers and the OPUS ones.

    OPUS "thins" files to a 30 second interval, so do a little math and figure out how many epochs at both 14 seconds and 30 seconds match up in 20 minutes.  You had 2.... one at 7 minutes and one at 14 minutes.

    Therefore OPUS could only process those two readings out of the 20 minute observations.  A 5, 15 or 30 second interval would all give you 40 synced observations.

    Review the following info page from NOAA and set your receivers to match - when ever I collect data for post processing, I use 5 second interval because I will process my own observation network first, then I will OPUS session the two best or most obstruction free points to upload to OPUS.

    Bottom line, the problem is with your receiver recording interval settings.

    Hope this helps,


    OPUS: the Online Positioning User Service, process your GNSS data in the National Spatial Reference…
    Process your GNSS data in the National Spatial Reference System
    • Bill,

      My Bad, I missed the "one out of five" part.  I'd suggest the you look for obstructions that might be interfering with this point.  Also, if its an important point, try running a 30 minute session.  While I have ran many, many OPUS sessions - both Static and Rapid Static - I rarely use a 20 minute observation except in the most wide open locations and at times that have the best/highest GPS Sat count.  Remember OPUS does not process GLONASS or any other data, only the USA's GPS.

      Again, sorry for jumping the gun on my first post,


      • Land Surveyor


        I think you were right about obstructions being the issue.  I moved to a higher point and the new point was processed without issue.



  • Land Surveyor

    I run OPUS static with my antique Topcon Turbos (8 channel L1/L2).  Always at least two simultaneous points, sometimes up to 4 at a time.  I always run at least 2 hours, and get 0.01 meter RMS.  I also post process them against each other as a check, and then use them to control my total station.  Your high RMS may be a result of your short sessions.

    I also find the data rate is not that important in the longer sessions.   One minute works just as well as 15 seconds, but the files are a lot smaller...

    I am not familiar with your TPS files.  I convert my files to RINEX so I can edit them with notepad.  You might convert all of your files to RINEX, and them check the fist few readings to see why the one file failed.  If you need to need to remove a few reading from top of the file, just remember to edit the session start time to match the first reading.  

    As long as you save your original files someplace safe, you can keep editing the file and resubmitting until it gets accepted.

This reply was deleted.

Answer As your Facebook Page

Members Do Not See Ads

Latest Discussions by Category

Help Us Preserve and Promote Land Surveying

Members Do Not See Ads


Land Surveyor Community Forum

Most land surveying related topics are evergreen - meaning the topics of discussion are many times timeless.  If you have a question regarding Land Surveying in general, this is the place to ask your questions.    

Add Discussion

Find a Hub Forum to Post In

Forums for  Hubs for Land SurveyorsHowever, if you have a questions regarding a specific type of Land Surveying Equipment, Surveying Software, Land Surveying History or other topics related to land surveying, you will find that our Community Hubs all have dedicated forums.   Asking your questions inside these Hub Forums will ensure that you are asking a targeted audience of land surveyors who are following those topics.

Forums for Location Based Chapter Hubs for Land SurveyorsLikewise, you will find that all of our Location Based Chapter Hubs have dedicated forums for discussing land surveying topics related to specific locations around the world.  Asking your question inside the appropriate place inside the community will most likely get you the most feedback.   Enjoy!  We look forward to helping you solve your problem or expand your knowledge of land surveying.

Below are the categories for our general forum which spans entire global community.

Find Hubs Based on Location, Equipment or Type
Global Surveyor Map (members)

More from Land Surveyor Forum