RTK solution Without Internet

Community Projects
1

Hello All,

System Nomenclature: Self-Survey

System Requirements: Accuracy 2 cm LAT/LOT, 3 cm height, no real-time internet connection.

I have looked/read through a lot of different blogs related to RTK connections and on most of the setups they talked about utilizing an NTRIP Caster that requires an internet connection. From this link: https://learn.sparkfun.com/tutorials/ho … ster-setup they mention an advanced trick that utilizes radio comms to send the RTCM data between the basestation and the rover. Assuming I follow the procedure for ‘Creating a Permanent Base’ will I:

1.) Be able to send my RTCM data w/o the NTRIP caster?

2.) Will I still get cm accuracy?

Thanks,

Slygo

2

The base station would need internet access at some juncture to receive its correction data (which can then be sent over radio, BT, wifi, or serial), you’d likely see ~2.5m accuracy without a correction stream

Run through the ‘Corrections’ guides (there are 4 sections) to glean a better overall view of how it all operates in practice https://docs.sparkfun.com/SparkFun_RTK_ … n_sources/

3

You do NOT need internet at all in the field with a dedicated base station AND a telemetry radio (such as the suggested 900Mhz telemetry radios) AND your rover is in radio range of the base.

If you are looking at absolute location accuracy, you will need to survey in the base station at the location you plan to run it, take that data (after 24hrs of data collection) and bring it somewhere you do have internet (home, work, office, etc), and submit it to a facility to get the corrections done and get your absolute location of that GPS antenna. You can then go back out to the device and locally load in that location, then it can go into base mode and issue RTK corrections.

The base essentially is outputting a data string every second or so over a serial link. That correction needs to make it into the rover, a serial link is fine. Any method you can get that data to the rover in a timely manor is fine.

4

That is what I thought, but every article, except for a few here and there, kept mentioning that you needed a NTRIP Caster. So, I wasn’t sure if this was possible or not, without buying the equipment necessary and testing my idea! Thank you JimKusz for clearing up that confusion for me!

5

so what SparkFun parts can I purchase to achieve this goal?

I need a base station that I can “plant” on job sites that will transmit the data to my enterprise-level drones.

6

Not sure if this thread is still active, but I’ve been successfully sending local correction data to a radio connected to a Raspberry Pi running RTKLIB. What’s driving me crazy is trying to figure out how to connect my controller to the base using just Bluetooth. I don’t get why there’s such a heavy push to rely on internet-based solutions when most of my work is in areas without any connectivity. It seems like there has to be a way to set the base into access point (AP) mode and connect to it directly from the controller to receive RTCM corrections.

Logically, the simplest approach would just be to connect the controller to the base over Wi-Fi—directly—without having to configure four intermediaries just to get a data stream. All that complexity introduces lag, more potential points of failure, and ultimately degrades accuracy.