Alpha RTK on phantom 4 for PPK

[aleskou]

Hello,

I am Aleskou, i leave in France, 38, I am an agronomist, i want to sell accurate maps and help integrating those technologies for the end user.
I am really not an electronician or ingeneer, so i might make big mistakes, please be indulgent.

Just to share my work, i am advancing on PPK, i just found a way and time to cleanly fix the alpha on my drone (phantom 4).

It doesnt involve any modification on phantom 4.

I bought & mount for fixing a 360 camera on the feet of phantom 4, fixated a pole for the gps and tangled the antenna cable and alpha.

Power comes from micro usb of phantom 4

Here is a picture, i made it hover in my garden, but the weather is not very good for real try.
The GPS fix on phantom 4 didnt seem to be worse with the antenna.

The plan is to log alpha as rover on phantom 4 and log alpha as base on a fix point.
Then retag the pictures.

Process would be
1 Put base and rover in place
2 Start tag on base and rover
3 Take picture of GPS time displayed so i might be able to find the good timing for synchronizing the solution and exif time date from picture
4 Fly with drone deploy
5 Process in RTKLIB both logs
6 retag with geosetter

Full weight is 1.610 kg

PS : I should add collars around the p4 arms to hold the mast of antenna

[nsicad]

Hi Aleskou,

I think you have to trigger the “External camera trigger input signal” from Phantom 4 Drone when the Phantom camera take a photo. LED of the Phantom 4 can be used.

Related discussion here.

PPK for gis mapping?

Please see section 3 Table 3-1 description item #6 on start/stop control of SD Card logging. One can log a file for each survey location if needed. If the SD card logging is not turned off between the survey locations and assume everything is stored into a single file, if the receiver is kept stationary for several minutes at the survey locations, then when doing RTKLIB post-processing one should find clusters of points at the survey locations and be able determine center of the cluster. I’m no…

Noli

[nsicad]

Camera Trigger in pin 3 in 4- pin port for PPK.

Get triggered positions from SD-card log files of Alpha

Hi, Here I would like to show the processes of getting the trigger positions from SD-card log files of base and rover. Roughly speaking, the log file in Alpha’s SD card contains [both base and rover sides] GNSS raw measurement data. [rover side] GNSS raw measurement data at regular sampling points at 1/5/10 Hz. [rover side] GNSS raw measurement data at trigger points (trigger input comes from pin 3 of the 4-pin connector on Alpha). The processes to retrieve trigger positions will be From …

Noli

[jim]

Hi Alesko,
Thank you for your sharing.
Your scheme of synchronizing the exif (with accurate GPS time) of picture and PPK locations should work quite well.

[Rods]

Hello. As Aleskou, I would like to share the project we developed to realize the PPK on a Phantom drone. Improvements will still occur, but I believe it is turning into a good design as it does not interfere with any drone sensors. Follows as images (current weight with batteries and propellers, 1,613 kg)

[Rods]

[Rods]

[agusrahmadi]

Hello Rods,
How is your Project you developed with phantom drone With PPK ? how to get eventmark from alpha kit?

[Rods]

Hi ‘agusrahmadi’, to get the raw data I proceeded as instructed in the Alpha user manual to get the files of SD card from the Alpha BASE and ROVER using of RTKviwer “toos/SD timestamp acquisition” to get the file with stamps and also using the “locator.exe” executable provided by Polaris here in the forum, for interaction between the file of stamps and position files to generate the final file for geotagging the photo files, and here is the crossroads because files inserted in the locator.exe application with UTM datas cause an error with this solution. I am currently getting the data manually for testing purposes using search tools like Notepad ++ to get the time stamp for testing on RTKlib in the version that was also provided here on the forum. In my specific case, the results are still not good, even when using the 10 Hz Alpha Rover but also because I have work to do with antenna mount vibrations and also the time gaps I get from using the arm LEDs from Phamtom. I’m waiting with Alpha (I have not given up yet) because I already expose this problem here in the forum and they asked for a while to check.

[Rods]

ps. my english is not good so … please forgive me if i couldn’t express it correctly. Anyway, I’m available for any questions.

[sergesurvey]

Excellent work! what about the orange box? does it come in the alpha kit or did you buy it in other place? (My first alpha kit will come soon)

[farhate]

Hello my friend. Could you tell me where you bought this 3D kit?

[JAILSON]

if this works it solves the problem of using phantom 3 for PPK, can you set up a step by step to make the changes to the coordinates and how to set the time to be compatible with both the gps and the camera?

[nsicad]

I think Alpha+ would not work in this hack for Phantom 4 or any UAV.

Pin 3 is disable now in Alpha+

PPK is only useful with camera photo with SD logging with time mark recording that can be synced with the time in the photos.

Noli

[nsicad]

Pin 3 will be working soon.

See the reply here.

PPK for gis mapping?

[Screen Shot 2020-08-13 at 12.48.10 pm] I don’t know why Pin 3 is no longer use to trigger the record the timing of taking picture in Alpha+ This is no good now. Alpha+ for Phantom 4 PPK. Noli

Noli

[Geoatacama]

Hi, if we use the LED to send a signal through LDR darkness sensor, but this signal can be sent directly or needs to be processed by some type of module? I hope you can help me, thanks

[nsicad]

Yes, I understand the “LED” signal and “LDR” darkness sensor. However, in Alpha+ the pin3 is not working to be attached to the “LDR” darkness sensor.

Pin 3 is disable in Alpha+ hence “LDR” darkeness sensor would not be working.

Edit: It seems updated now. So, pin 3 is working now for Alpha+

PPK for gis mapping?

Will have update firmware supporting this next week.

[Geoatacama]

Really? good news, then how should be the signal to make the photo location link, do you have an example that can guide me?