NTRIP Caster is an amazing feature, at the moment we can use it with DJI RTK Drone.
In fact, the drone position is corrected by its Remote Controler which is connected into the EMLID CASTER by NTRIP using Internet. The RTK drone can only be used in RTK using NTRIP correction by its Remote Controler.
It works well, but many users can’t use internet on their field. In my case I can only use it 50% of the time because there is not cellurar data network.
The work around is to use TCP ouput correction using a laptop + routeur : which is not ideal because it adds weight, devices, batteries, settings, etc.
For thoses reason many DJI RTK drone users buy 1 RS2 (in order to put Gcps) and 1 base (from other brand) which has the feature of casting NTRIP by wifi.
My post is to ask EMLID Team if there is any plan to release a such feature?
And also to see how many people has the same need as me? I saw many many DJI RTK drones users on facebook looking for this feature.
Good stuff right?! The But is that you need internet of some sort with NTRIP. When you mention WiFi I assume you mean hotspotting to the controller? We do the same with a Yuneec H520E RTK and I will not miss 20 GCP’s in the Texas sun… we still set 3 for map calibration but obviously that’s a way cooler workflow.
When I say wifi, we need the RS2 to able to do NTRIP without internet, but by using wifi in local : no need of internet. Remote controler connected by wifi to RS2 with NTRIP correction.
DJI RTK drone only work with NTRIP : either with internet using EMLID CASTER, or with wifi with DJI DRTK or others bases station.
What we would like is Emlid does the same feature.
What do you mean by Wi-Fi without the Internet? At the moment, it’s not clear to me.
NTRIP always requires an Internet connection. It works like this: the base sends corrections to an NTRIP server, while the rover gets corrections from it. These data streams require an Internet connection.
However, if your worksite doesn’t have a stable Internet correction, there are also some workarounds. For instance, it’s possible to transmit corrections to a drone’s controller via TCP if it provides such a feature. You can check how to set corrections output via TCP in this article from our docs.
We always take users’ feedback into account. So please provide me with more details of your feature request. It’ll let me understand exactly what you need.
The idea is to send corrections directly to DJI’s tablet, which sends corrections to the drone. The tablet can receive NTRIP corrections over WiFi.
So, it would be nice to run the NTRIP Caster locally on the RS2 itself. So the tablet connects to reach WiFi with no internet access. But because the Caster is run on the RS2 itself, the tablet would be able to pull those corrections.
There is no reason I can see technically why the NTRIP caster can’t run directly on the receiver, however it may have something to do with limitations in available processing overhead, as the receiver is already calculating corrections for RTK, it wouldn’t require much though as I don’t believe it would need to parse the data, only proxy it through. Alternatively (and I will add not a great solution) you can use a raspberry pi running open source ntrip caster software and connect it to the rs2 via wifi using the pi as a hotspot, output rtcm over tcp to the pi and connect the dji controller to the pi hotspot, use the pi gateway ip address as your ntrip caster address in the dji software.
Its a shame we currently need to have a middleware solution but one positive is the odu connector in the RS2 does output 5V at 1A so you can look to power the RPI off this and if you wanted to go even further, wire the pi to the RS2 via serial for a more stable RTCM output connection.
I’ll make a better answer for you tomorow (it is very late in my place), but the point is:
I need a local NTRIP server generated by RS2 that would use the local WIFI network to do the correction with other device.
Either the RS2 itself could create a local NTRIP and do the correction using its wifi, or the android device could be the NTRIP server (but it should have a strong stable connection with RS2… maybe by bluetooh).
At the moment, the only workaround I found use RS2 with : output TCP into my laptop then create a NTRIP server in my laptop and connect my Remote Controler (Drone) to this wifi network to be corrected by NTRIP (without internet).
In my opinion, it s doable, this feature is available on DJI base station … but I clearly do not want buy another brand than EMLID as second base station… And I’m sure we are thousands in the same case.
Much like how the skycatch Edge1 base works, it can cast corrections by wifi network without an internet connection as it runs the ntrip processing internally.
Even if there was more information on setting up TCP might give us a bit of a start.
As I understand it now, you need a feature to pass corrections from Reach without an Internet connection.
For such a case, you can output corrections from Reach via TCP. To do it without the Internet, you can switch Reach to the hotspot mode and connect your drone’s controller to it. It won’t use NTRIP protocol, but in this case, it’s not needed.
I am not familiar with the DJI base’s features. So, if I got you wrong, more details from you would be of help.
The issue is that DJI requires NTRIP. You can’t pass corrections over TCP. So, the requirement is to receive correction over NTRIP from an RS2 without internet access.
At the moment the ONLY solution to use EMLID RS2 with DJI RTK drones, is with NTRIP output correction using internet (using EMLID CASTER)
Without internet there is an alternativ which is to use Ouput correction in TCP connected to a laptop on which is instaled a local server NTRIP. Then the laptop will send correction by wifi to the DJI RTK Remote Controler
The 2cnd alternativ is not a good solution because it add devices, weight, batteries, time to instal. This is not really efficient, not simple and hard to use in real conditions.
So the feature we request is : RS2 does its own local server NTRIP in order to send correction directly to the DJI RTK Remote Controler by wifi.
There are several methods he could do. He is trying to do it with less components.
I originally said something along the lines of a laptop running SNIP with a wireless router. The wireless router would require a power source as would the laptop
There is an android app that can act as ntrip server if configured properly.
RTKGPS+ is the app and i think there is a beta version with ntrip caster functionality.
I have successfully sent the corrections from M2 to the app via bluetooth and then output the stream to another caster. But this also works with internet.
You can download the rtkgps+ here.
And here is the official page GitHub - eltorio/RtkGps: Playing with rtklib on android
About RTKGPS+, if there is a need to use internet, I still prefer using EMLID CASTER which avoid me to use an android device for this purpose, and which is more stable.
But Thanks, I’ll have a look on this app.
So, the idea of my feature request, is than EMLID RS2 generates its own NTRIP local server, and then be able to correct position of “NTRIP’s client” rover (like the DJI RTK Remote Controler) in wifi without the need of any other device : neither Android or Laptop + routeur, and without the need of internet network.
Technically it should be faisable.
At the moment NTRIP provided by EMLID Caster only works with INTERNET, but that doesn’t mean that NTRIP technology can not work in local network without internet. It works well, and is designed to be used on any network.
I would like to know you point of view about that @julia.shestakova
Do you think it could be done? Do you see the potential of this feature for DJI RTK users and the actual limit of using EMLID with DJI DRONE for RTK purpose? Do you think it could be done soon?
