Obtaining FIX without nearby NTRIP

New user of RS+ here. I live in Hawaii and no amount of googling can turn up any NTRIP stations on my island. If I’m reading the docs correctly, I need to be within 15km of the NTRIP base to get a fix. I tried using rtk2go but the nearest station I could find is 3000km away and those can’t get me past float. What are my options for getting that centimeter accuracy I thought I was paying for with this device? Hire a surveyor to locate a spot on my property for the base to go?

Do you have 2 rs+?

Yes, I have two RS+ units. I can obtain fix between the rover and base but I want centimeter accuracy in global coordinates, which means my base needs to use “average fix” positioning, which requires an NTRIP connection < 15km away.

Which one of the cors are you closest to?
https://www.ngs.noaa.gov/CORS_Map/

You can download historical data and process against your base to create a new known point. And from then use base to do RTK with your rover and the new created base point.

Option nr 2 is to use a VRS service, do you have access to such service?

Looking at that CORS map, I’m a few miles from the CORS station at Hilo airport.

I do not know what a VRS service is.

OK, if you dont have a subscription for either VRS or a live refrence station you have to create your own.
If you do alot of stakeout and the range is more then 10km from a place where you can make a new point i would consider VRS service. Is this a one time job or?

How do I integrate VRS with the RS+? Is a VRS service the same thing as NTRIP? I see there is the Trimble NOW service which looks expensive. It would probably be worth it to me as I will be continuing to collect and stakeout points for at least the next year.

VRS is service that creates a virtual base close to your rover. Very much like ntrip and conneting to a real base station but it usually states VRS or something on the mountpoint. For your rover it acts like a base but you cant see it in the real world.
Not sure who offers this in your region.
The closest live station i found is to far way from you. https://igs.bkg.bund.de/dataandproducts/streams
Your could try look up others from here https://www.gpsworld.com/finally-a-list-of-public-rtk-base-stations-in-the-u-s/
If not i would consider VRS if you do these jobs often and further away from a base then 10km.

I just looked more closely at the Trimble VRS and it’s coverage map is pathetic! Covers like 20% of the continental US, Europe, and Australia.

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Can you point me to any resources explaining how to do this? I was able to download historical data for my nearest CORS, but how do I process it to create a base point?

Have you read this https://docs.emlid.com/reachm-plus/common/tutorials/gps-post-processing/

Yes, I have, and unfortunately all of that PPK stuff seems to require software that runs only on Windows OS. I am a Mac user. I supposed I could run Windows on VMWare or something.

This is getting insanely complicated. I had no idea what I was getting into when I bought this product.

RTKlib is standard build for linux and win yes, but the code can be rebuild to be run on MAC too, if you know someone that does code?
If not there is other processing tools you could buy. I dont know of any other free ones

So you dont really need RTK for stakeout?
Most user post process and this should much easier then live RTK.
https://www.effigis.com/en/solutions/onpoz/ezsurv/ is one application used by some in this forum

Try to find a way to run windows on a Mac


Good luck !

And its about to get much worse :slightly_smiling_face:

I do want to use RTK for stakeout in the future, but drone GCPs are my main priority right now.

Emlid created a good product, but boy they still have a long way to go, especially with documentation. The whole point of this product is centimeter accuracy and yet there are so many extra steps and extra services required to make it happen. Why do their docs just casually mention NTRIPS without pointing to a directory of them, or mentioning that large portions of the globe don’t have access to them? Kind of a big detail to leave out.

To anyone reading this and considering buying this product because you want a GPS that is more accurate than your phone and your drone… be prepared to take a week off learn about every idiosyncrasy of mapping technology before you get what you paid for.

You would probably face the same issue with topcon, leica etc. But as you saw for your self, the VRS service would not do you any good, and you would have spend much money too.
That leaves you with refrence stations. The recommende distance is 10km for RTK but PPK could be much further in static mode.
Ntrip is just a function, and works globally. You could use your own base as mountpoint and do a static survey with baseline up to 100km or even more with good results, so dont roll over die just yet :slightly_smiling_face:

In your scenario a static rover connected to a refrence station could have a long baseline. You would run rover a static for some time (x minutes) in static. This would get you good absolute position. Then save coordinates and change your base from rover to base and stream correction over lora locally or for further distance via ntrip and internet.
I use this workflow often as i dont have a VRS service and as you, dont have any nearby refrence stations when doing rtk stuff

Hope this helps

Another option is to setup the base station over a known point, you can find a list of them here:
https://www.ngs.noaa.gov/NGSDataExplorer/

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Could someone explain what @alohajoe is trying to do. I have never connected to a VRS/CORS, only used data that was posted so I am not understanding how you can get a fix without service or a base.

Or @alohajoe are you trying not to use your base as well?