PPK Missing Events

I am going to try these settings for my next test today, exact settings applied to my base and rover units:

Thanks Tatianan for the infor regarding the base information. I will input this in my next post processing.

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If you have 2 units you could test GPS and GLO vs GPS and GAL. I think the second is the better configuration.
@wsurvey recommends to use BEIDOU as well (GPS, GAL & BDU) and fix probably missing events in post processing. He recommends GeoAdjusd which works for P4P images from DJI and I have writtem a tool to match images and events regardless of the camera manufacturer and the time settings. I have greatly profited from @wsurvey earlier recommendations and will adapt these settings for my next campaign. I will have the possibility to check against a Leica device and will report.

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I performed 12 flights over two days last week with the Altum and the Reach M+/RS+ system. I plan to begin the Reach processing today, then import the data into Pix4d for processing. I have a question regarding setting the RS+ antenna height in RTKPOST ver 2.4.3. I am in OPTIONS window as seen below:
I have the coordinates of the base station location collected from an L1/L2 GNSS CHC system, processed in OPUS in the USA. I have the Easting, Northing, and Orthometric height of the surface point on the ground where the base was located. I put my RS+ on a 2 meter pole at this location. If the ground base location is 1531.0145 m (orthometric height) should I enter the height in the Delta U as the ground elevation, ground elevation plus 2 meters (for pole), ground elevation plus 2.022 (2 m for pole and 0.022 for 1/4" to 5/8" adapter), or ground elevation plus 2.087 meters (2 m for pole, 0.022 for the 1/4" to 5/8" adapter, and 0.065 for the distance between the bottom of the Reach RS unit and the center mark?

In addition for the Easting and Northing location to I enter this in the Delta E/N/U (m) field or in the Lat/Lon/Height (DMS/M) field? I tried entering this info in the Delta E/N/U and recieved an empty position file from the output. Thanks everyone for your help.

Delta is for the antenna offset. That is your pole only. You need to convert your coordinates. You can use the height without conversion, I think. You also need to read the manual… .

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I think the ground elevation and pole offset should have either been accounted for in in Reachview or whatever data collection software you used making the drone relative to that ground elevation. All you should have to do is enter the antenna offset for the rover (drone) and the base ground elevation converted to meters. I would put the base position in QGIS as a point with your XYZ (State Plane?) coordinates and export it back out as WGS84 - unless you have another converter.

Hello, from RTKLIB manual 2.4.4

(5) Position (pag. 43-44)
Base Station
Lat/Lon/Heig ht (deg/m)
Set the position of the base‐station antenna.
‐ Lat/Lon/Height (deg/m): Latitude/longitude/height in degree and m
‐ Lat/Lon/Height (dms/m): Latitude/longitude/height in degree/minute/second and m
‐ X/Y/Z‐ECEF (m): X/Y/Z components in ECEF frame.
‐ RTCM Station Position: Use the antenna positionincluded in RTCM messages
‐ Average of Single‐Pos: Use the average of singlepoint solutions
‐ Get from Position File: Use the position in theposition file. The station is searched by using the head 4‐character ID of the rover observation data file
‐ RINEX Header Position: Use the approximate position in RINEX OBS header.

Set the delta position of the base‐station antenna as E/N/U offsets of ARP position with refer to the marker (m).

Reach RS+ U (m): 0.065 (ARP to L1)* + 0.0215 (adapter 5/8" to 1/4") + heigth of rod and other adapters

*As RS+ is not included in the IGS antenna file, it must be added

Greetings to all
Saludos a todos

I have exactly the same Problem. About 50 Time mark Events are missed!
I have used the following Settings for my PPK (base aund Rover the same).

The Observation file from Rover:

All data was downloaded and processed using EMLIDs rtkconv and rtkpost apps using the recommended settings found online.
I do not know the recomended RTK Settings for Germany! Any Idea?
Thanks alot.!

Hi Maryam,

For time mark logging, we recommend using one of the following settings:

System Frequency
GPS 10 Hz

Otherwise, time marks can be lost.


Hi Tatiana,

thanks alot for your answer. Now i have all my timemark events :). I use PPK with Base and Rover. The events.pos : Rover_Sapos_Base_201910231053_events.pos (126.6 KB)

The Question is: Q= 2 , but the sdn, sde, sdu are all in mm. Q=2 means Float : accuracy is submeter-level, but my standard deviations are all in mm ? Whats wrong?

Thanks alot.

Hi Maryam,

Glad to hear you managed to get all the time marks :slightly_smiling_face:

May I ask you to share raw data from both base and rover? I’d like to check your observation data quality and try to post-process them.


Hi Tatitana,

the files are too big and i can not share them here. How can i send you the files?:sweat_smile:

Hi Maryam,

You can upload them on WeTransfer as Christian suggested or use any other file sharing service :slightly_smiling_face:

here are my files. Thanks alot

Hi Maryam,

We’ll check them and get back to you!

Your Rover SNR quality is so bad!
There are a lot of slip rings in it.
Such data will not give you a fix.

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yes…I know.
But i use post-Processing of my data and the goal is to improve my accuracy.
After post processing get it Float.

Change antenna first.
Then try to make survey again.

Signal-to-Noise-Ratio and accuracy go hand-in-hand. Fix your receiving-conditions (antenna, noise sources, location) and you will get a fix-solution eventually.

i have a question:
I got this Positions after Post-Processing
Sapos_Base_Rover_201910220911_events.pos (151.0 KB)
Are they all wrong,because of SNR?