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Example of PPK for photogrammetry in Croatia

Solution

This is a real example of PPK for photogrammetry in Croatia

 

The RTKite is used without RTK, only RAW data are used. So, there are not connections to Base or Cors. Only one RTKite unit with the PhotoKit.

 

https://www.dropbox.com/s/dtvci1ws174blnm/IMG_20170504_211537.jpg?raw=1

 

The camera is a Sony A6000

 

https://www.dropbox.com/s/cu5cin1ud1ligep/IMG_20170504_211733.jpg?raw=1

 

 Setup

 

1)      The RTKite was setup in Drone UHF mode (without UHF modem connected) because is the most quick mode to initialize.

 

2)      Pressed the Push-Button for start to log file RAW (you can also configure to Start Log Automatically)

 

3)      Flight with photos. 10 min flight on the 50m AGL with 4m/s speed.

 

4)      Landed and stopped to record file RAW by pressing again the button.

 

The files generated

 

1)      PPS_FILE_10052017_0826_0001.NOR

This is the RAW file. In this file are the RAW observations and events for each photo. This is the only file that will be post-processed.

2)      PPS_FILE_10052017_0826_0001.LOG

This file was created because the “Extra Log” setting was enabled in the App. This file is not used. But you can check that GPS is in SPP mode (not RTK), by watching field 4 (value 16)

3)      PPS_FILE_10052017_0826_0001.TXT

This file is also not used. Here are the coordinates of each photo in real-time, so, with SPP accuracy (not RTK). Field 2 (value 16)

 

The Work in desktop, the “post” side

 

In folder Rinex, these are the files generated from PPS_FILE_10052017_0826_0001.NOR using “RTKLIB 2.43 by NORTH”

 

PPS_FILE_10052017_0826_0001.nav

PPS_FILE_10052017_0826_0001.obs

 

Then, we need Rinex files from a near permanent station for our time interval. These files are:

 

 

ZAGR130I00.17g

ZAGR130I00.17n

ZAGR130I00.17o

The results

 

PPS_FILE_10052017_0826_0001.pos

This file was created by the process of RTKLIB, here are the positions of drone during the flight. The field Q=1, so accuracy of each position is FIX.  In this file, you can see also the error (in meters) for each position. This file is not used. The coordinates of photos are in the "_events.pos" file

 

PPS_FILE_10052017_0826_0001_events.pos

This file created by the process of RTKLIB is our end goal. It has the same format than above. In this file are the coordinates  of 159 photos taken from the camera. The field Q=1, so accuracy of each position is FIX and each error is computed.

 

https://www.dropbox.com/s/0j5gdn3drf1xgp7/processed-events.png?raw=1

 

 

In Red is the track of flight, in Green the coordinates of photos

https://www.dropbox.com/s/xpx0pj21p7j1ipy/google.png?raw=1

 

Full files here

https://db.tt/ZfOuwACNBV

 

Related articles How to Post Processing Kinematic (PPK) for Photogrammetry
TXT File Format
LOG File Format
Flash synchronization
What's the "Use Location" option in the App for CORS configuration
Article details
Article ID: 23
Category: RTKITE FAQ

 
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