Land Surveyor Community Forum

I don't even no where to begin... I am involved with a group that is in Ethiopia and the want to set geodetic control.  They have access to a trimble R8-2 and TSC1.  What is the process like...I mean I understand the post processing in the States, but I have no idea what the process is outside of the USA.

Anyone?

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

Join Land Surveyors United - Surveying Community & Forums

Email me when people reply –

Replies

  • Great help from all...thank you for the guidance and feedback.
  • Dear Sir,

    It’s my pleasure to send my suggestion on basic geodetic reference control point input for geodetic/supplementary survey works in Ethiopia.

    You can get CORS, Zero Order, 1st order etc basic control points data either from shelf, depending on your project location, or you can get service to establish (GPS surveyed and processed) for a particular project from Ethiopian Mapping Agency, the only national mandated organization to make, archive, manage, administer, disseminate, regulate and assure quality of geo-spatial information (fundamental geo-spatial data set) throughout Ethiopia.   

    With Best Regards

    Girma Habtegiorgis

    • If any addtional question please do ot hesitate.

  • You need reference (base) GPS data from a known point. If there is no control points with known coordinates, you can try to use either the NGS's OPUS service or the Australian AusPos.

    In this case you need to collect enough raw data on the point you have to use. Enough means several hours, because NGS and AusPos will search for the nearby known GPS base stations, but sometimes the closest is 500-1000 km far from your point. The longest your data is the best chance to get fix position from the mentioned services. 4 hours was enough for me to calculate a vector from Hongkong to Hanoi (800 km), but 12 hours was not enough from Bahrain to Tehran (1100 km)

    The logging rate must be about 1 per minute, or 1 per 3 minute if you want to use these external services.

    If you can find base stations closer to your point, and you are processing the data with your own sw. such as Trimble TBC, you need to log raw GPS data at the same rate which the Reference stations are using (1/sec..1/15sec, etc), and the length of your data may be shorter (30 minutes if the base is 10-20km far from you, 1 hour if the base is 30-50 km, etc.)

  • This has some useful info. Might be the place to start.

    https://www.ngs.noaa.gov/INFO/Policy/files/052013_International_OPU...

    https://www.ngs.noaa.gov/INFO/Policy/files/052013_International_OPUS-GNSS_Policy.pdf
This reply was deleted.

Help Us Preserve and Promote Land Surveying

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