PPK?

[EarthImage]

Hello, given that the EVO 2 RTK seems to be a mystery bird (NO documentation), I was wondering if someone could give me some information on how PPK is implemented?
1. Are shutter time-marks embedded in a RINEX file?
2. Can one select which satellites to use and the collection rate (Hz)?
3. Any chance someone has an example project and procedure that they could share?
4. How are folks post processing the RINEX data? RTKLib?

The lack of documentation and information on this new RTK drone is pretty strange.

 

[ChristianH]

Hello, given that the EVO 2 RTK seems to be a mystery bird (NO documentation), I was wondering if someone could give me some information on how PPK is implemented?
1. Are shutter time-marks embedded in a RINEX file?
2. Can one select which satellites to use and the collection rate (Hz)?
3. Any chance someone has an example project and procedure that they could share?
4. How are folks post processing the RINEX data? RTKLib?

The lack of documentation and information on this new RTK drone is pretty strange

Are you wanting to use RTK or PPK? I believe RTK coordinates are embedded in the EXIF data if you are getting base corrections according to a video on a 640T thread.

I use RTKLib for other projects so I'm also interested in finding out how the RTK module operates on the Autel.

 

[EarthImage]

Are you wanting to use RTK or PPK? I believe RTK coordinates are embedded in the EXIF data if you are getting base corrections according to a video on a 640T thread.

I use RTKLib for other projects so I'm also interested in finding out how the RTK module operates on the Autel.

I want to know how PPK is implemented. What this means is that when a mission starts the drone will be set in a mode that collects raw gps data in a kinematic mode, that is collected to a file. What gps coordinates are embedded to the EXIF data when a photo is taken is of no importance. What is important is that when a photo is taken that a time mark is added to the raw gps data. So if one takes 100 photos, at the end of a mission you should have precisely 100 time marks. Using these time marks the precise XYZ position of each photo can be interpolated once the raw gps data has been post processed. These post processed XYZ points are used as image centers. So in PPK a stationary base station, over a known point, also has to be used (so you have something to post process against). The beauty of PPK is that no radios or correction data is required when flying. Also, and more importantly, when the raw gps data is post processed one knows the actual accuracy of each point, especially whether it is float or fixed. When flying RTK there is no meta data (that I know off) that records whether the point embedded in the EXIF data is float or fixed. This could have grave consequences when survey grade accuracy is required. Anyways, I'm just wondering about the hesitancy (or laziness) of Autel about giving information about PPK capability. It seems silly. They are sure doing their best to keep me from buying this drone (I use the EVO 2 Pro for mapping using gcps).

 

[ChristianH]

We are on the page it seems. I am a fan and user of PPK, not so much RTK as it has many pitfalls and serious consequences when one of the components fails (usually a radio link) in the field. If you don't specifically need RTK methods then it's a waste of money and time. I'm not a fan of black box RTK (Ex Trimble user).

I've used a separate GPS module on board to log shutter events and a static base for PPK but that's not an option here.

I suspect that there is no logged event data stored in a RINEX (or similar) file and that the RTK position is only in the EXIF data of the image. It would be good to get some test flight data by a pilot who has the Autel RTK module.

I process PPK with RINEX files so I don't know if there is a workaround to do a single event with only the base station RINEX data?

 

[vr-pilot]

I want to know how PPK is implemented. What this means is that when a mission starts the drone will be set in a mode that collects raw gps data in a kinematic mode, that is collected to a file. What gps coordinates are embedded to the EXIF data when a photo is taken is of no importance.

Maybe you can take a closer look into the two videos posted her:
EVO2 Enterprise DUAL 640T RTK: maps and models of IR and RGB jpegs (NTRIP data)
I got some datasets from the Italian vendor and they include the real time corrected EXIF data imagery plus "100FTASK_Rinex.obs" and "100FTASK_Timestamp.mrk" files.

 

[madpuma]

I would like an update on this as well. I was one of the first to purchase the RTK unit when it came out (pre-enterprise). I bought it based on the marketing that it had PPK and it did not. The unit had all of the components there but it was software limited and the unit did NOT write information to the local RINEX file. This required you to setup NTRIP and use RTK. I am back interested in this unit again but I still dont see any information regarding if this issue was resolved or not. I frequently have to fly in areas that do not have any wifi/cell service and thus impossible to setup RTK.

Is it possible now to fly the drone without NTRIP enabled and still collect PPK data?

 

[vr-pilot]

Is it possible now to fly the drone without NTRIP enabled and still collect PPK data?

Maybe you could take a look here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and further below here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and in conclusion here:
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options

 

[madpuma]

Maybe you could take a look here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and further below here
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options
and in conclusion here:
Evo II Enterprise Pro RTK Drone - Autel Explorer App RTK Options

Only one of the posts mentions anything about the RINEX file. They say it is still written to but that is what I would like verification of because when I had the unit it did NOT write to the RINEX file.

 

[Dave Pitman]

The RTK equiped Evos are writing correct .obs and .mrk files with the latest 2 firmwares.

 

[madpuma]

The RTK equiped Evos are writing correct .obs and .mrk files with the latest 2 firmwares.

Thats what I needed to know. Is the obs in RINEX format?

 

[Dave Pitman]

Thats what I needed to know. Is the obs in RINEX format?

Yes, all good. I've attached a sample from a small project.

 

[reynolds8126]

Glad it appears using the RTK module for PPK workflows is possible. Considering the lack of documentation from Autel on this matter, can someone with success provide some documentation on the procedure? In the meantime, I plan to experiment with both the RTK via NTRIP and the PPK workflows. If I determine a straightforward procedure, I plan to provide that to the group.

 

[vr-pilot]

Glad it appears using the RTK module for PPK workflows is possible. Considering the lack of documentation from Autel on this matter, can someone with success provide some documentation on the procedure? In the meantime, I plan to experiment with both the RTK via NTRIP and the PPK workflows. If I determine a straightforward procedure, I plan to provide that to the group.

Probably I get an EVO2 Enterprise + RTK within the next two weeks. Will report about NTRIP & Co. as soon as starting the first tests...

 

[ChristianH]

Probably I get an EVO2 Enterprise + RTK within the next two weeks. Will report about NTRIP & Co. as soon as starting the first tests...

I'm waiting very patiently over here. Hopefully within 2 weeks of delivery now...

 

[vr-pilot]

I'm waiting very patiently over here. Hopefully within 2 weeks of delivery now...

That is great, congratulations!
My set will be on the way over the weekend, ETA next week I think. So it will be like Christmas in January! ;-) Really looking forward to it.
For European stakeholders I can recommend "Dronisport". Seems as they are quite the only sellers for EVO2 Enterprise here, at least talking for Germany.

 

[us100]

Здравствуйте, учитывая, что EVO 2 RTK кажется загадочной птицей (НЕТ документации), мне было интересно, может ли кто-нибудь дать мне некоторую информацию о том, как реализован PPK?
1. Встроены ли временные метки затвора в файл RINEX?
2. Можно ли выбрать, какие спутники использовать и скорость сбора данных (Гц)?
3. Есть ли у кого-нибудь пример проекта и процедуры, которыми он мог бы поделиться?
4. Как осуществляется постобработка данных RINEX? РТКЛиб?

Отсутствие документации и информации об этом новом беспилотнике RTK довольно странно.

Phantom 4 RTK - PPK Processing Workflow | Drone Data Processing

Phantom 4 RTK PPK Processing Workflow

www.aerotas.com

 

[Eelke]

After processing the rinex files from the EVO and the base station with RTKLIB we get the corrected antenna locations (pos file at 5Hz). Does anyone know of a software tool or workflow as to how to match the images with the xyz from the pos. And what are the xyz distances between the antenna and the sensor?

 

[Dave Pitman]

After processing the rinex files from the EVO and the base station with RTKLIB we get the corrected antenna locations (pos file at 5Hz). Does anyone know of a software tool or workflow as to how to match the images with the xyz from the pos. And what are the xyz distances between the antenna and the sensor?

The offsets between antenna phase center and center of cmos sensor is supposed to be already factored into the positions in the timestamp.mrk file. Although they are also listed in each event location.

Some are writing their own python scripts to align the event to the base observation as near as possible. There are a couple of paid applications (that I know of) that do this. Namely Toposetter and RedToolbox. Emlid is working on integrating drone timestamp files as well, but they are not there yet.

 

[elphtrooper]

Maybe not appropriate for this thread but it was the closest that popped up...

Emlid Studio through Beta

 

[Dave Pitman]

What timing. Emlid Studio just emerged from beta. It looks like they have included the use of the .mrk files from dji and autel drones!

Emlid Studio: PPK in a few steps

Great news for our users—we’ve released our post-processing software Emlid Studio! It is now out of beta and ready for everyday use. To get started, download the Emlid Studio for Windows or macOS and install it on your computer. It is completely free and works with any GNSS receiver. Emlid...

community.emlid.com