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Topodrone SA 

CHE-354.723.874 TVA 

Rue du Centre 39, 1637 Charmey, Switzerland 

+41 797 910 713 

info@topodrone.org 

www.topodrone.org

 

 

Page 21 from 42 

 

3.2 Initial aerial triangulation

 

As soon as images with precise coordinates were loaded to the project, we can start initial aerial 
triangulation. Select initial processing checkbox and start processing. 

 

 

 

Summary of Contents for DJI M200 L1/L2 PPK

Page 1: ...Topodrone SA CHE 354 723 874 TVA 1820 Rue de la Gare 13 Montreux Switzerland 41 797 910 713 info topodrone org www topodrone org TOPODRONE DJI M200 L1 L2 PPK USER MANUAL ...

Page 2: ...S receiver settings 6 2 GNSS data post processing and images geotagging 7 2 1 Data preparation 7 2 2 GNSS data postprocessing and images geotagging 7 3 Photogrammetry processing in Pix4D mapper 16 3 1 Creating a new project 16 3 2 Initial aerial triangulation 21 3 3 Camera calibration 22 3 4 Accuracy estimating 28 4 Photogrammetry processing in Pix4D mapper 31 4 1 Creating a new project photos ali...

Page 3: ... places and objects located nearby It is not allowed to fly in No Fly Zones airports prisons sports stadiums Military bases state institutions objects of strategic importance CHP hydroelectric power plants nuclear power plants etc are particularly dangerous but they are not marked at GEO services Electricity transmission lines located at the place you need to capture can cause radio and magnetic i...

Page 4: ...ne for it s arms horizontally Do not change the orientation of the drone 8 Rotate drone to the left side counter clock wise in 380 degrees a bit more than 360 degrees Stop when the rear LEDs will change color from solid yellow to solid green 9 Change orientation of the drone turning it in 90 degrees in a longitudinal axis 10 Rotate drone to the left side counter clock wise in 380 degrees a bit mor...

Page 5: ...the drone to the working altitude and move gimbal to the 90 degrees nadir Ensure that focusing method now is in the AF value Then tap to the center of the screen to let the camera focusing at the surface After that change focusing method in the MF value manual focus scale will appear Do not touch it Now drone s camera is focused at the selected height value It will not change in the future 4 Now i...

Page 6: ...MU calibration is not the same as the default To calibrate IMU you need to do next 1 Remove props from the motors if needed 2 Remove gimbal from the drone recommended 3 Turn on the drone and the remote controller 4 Prepare a flat solid table the horizon should be aligned to the bubble level 5 Start the IMU calibration process and make steps 1 5 as they are 6 At step 6 you should place the drone he...

Page 7: ... PDOP 10 Blinks rapidly 2 PDOP 3 Solid PDOP 2 5 Red LED Shows the critical of errors in the system If an error occurs check the memory card If replacing or reconnecting formatting the micro SD card does not solve the problem contact customer support 6 Micro SD card socket 7 Coaxial cable of the GNSS antenna Each time the receiver is turned on a new ubx file is created in the folder with the date o...

Page 8: ...folders For example Flight 1 Flight 2 etc NOTICE Do not delete any images Remove SD card from GNSS receiver installed on the drone and copy ubx files to your computer to a folder ROVER for example Download GNSS static logs from a base station and convert them to Rinex format Copy Rinex files to a folder BASE for example Mesure coordinates of ground control points GCPs and coordinates of the base s...

Page 9: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 8 from 42 Step 2 Select folder with photos ...

Page 10: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 9 from 42 Step 3 Select UBX file from a drone ...

Page 11: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 10 from 42 Step 4 Select Rinex or UBX file from a base station ...

Page 12: ...e 11 from 42 Step 5 Impute coordinates of the base station in WGS 84 Define antenna offset for a drone NOTICE FOR DJI MAVIC 2 PRO PPK use the following parameters Height 0 07 Offset forward backward 0 02 FOR DJI PHANTOM 4 PRO PPK use the following parameters Height 0 17 FOR DJI M200 X4S PPK use the following parameters Height 0 22 ...

Page 13: ... setting Advanced setting will appear To embed precise coordinates to photos EXIF tags check Burn exif check box This option may lead increasing of data processing time To save list of coordinates check Save text file check box Select format of text file Pix4D or Metashape Click Save button NOTICE To look at data processing performing switch on Display utility window option Click Start button ...

Page 14: ...ll steps of data processing data conversion GNSS data post processing images matching and geotagging all results will be stored in Output folder File Coordinates txt is stored in PIX4D or Metashape folder Photos with updated EXIF tags are stored in UpdateTags folder Files with pos extension are results of GNSS data postrpocessing NOTICE Coordinate system is WGS84 ...

Page 15: ...org Page 14 from 42 Step 7 Checking processing results After processing accomplishing the following buttons will appear NOTICE Click buttons in front of Rover or Base fields to open GNSS observation files to check the quality of GNSS signal To check quality of GNSS data postprocessing click button in front of output results ...

Page 16: ...olution Yellow points Float solution Red points Single solution NOTICE If there are only red points on the map it means that GNSS data from a drone and a base station were not collected at the same time If there are only yellow points float solution you should check coordinates of a base station or quality of the signal To remove noisy GNSS signal try to increase satellite mask angle or exclude GL...

Page 17: ...mey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 16 from 42 3 PHOTOGRAMMETRY PROCESSING IN PIX4D MAPPER SOFTWARE 3 1 Creating pix4d mapper project Run PIX4D mapper application Click New Project Select a project folder location Click next ...

Page 18: ...one SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 17 from 42 Select images to be processed from output UpdateTags folder Click next ...

Page 19: ...ead precise coordinates of images and accuracy setting automatically Click Next NOTICE It is possible to upload coordinates from txt file Click From File button and select coordinates txt file It is recommended to check camera settings Cilck Edit button and check if Linear rolling shutter camera model is enabled in case if DJI MAVIC 2 PRO was used for survey ...

Page 20: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 19 from 42 Select output coordinate system and click Next ...

Page 21: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 20 from 42 Select type of data processing options Click Finish ...

Page 22: ...and 41 797 910 713 info topodrone org www topodrone org Page 21 from 42 3 2 Initial aerial triangulation As soon as images with precise coordinates were loaded to the project we can start initial aerial triangulation Select initial processing checkbox and start processing ...

Page 23: ...TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 22 from 42 3 3 Camera calibration In order to calibrate focal length of the camera you need at list one GCP Click GCP MTP button ...

Page 24: ... 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 23 from 42 Select coordinate system of ground control points and import GCPs Click OK Change GCPs type to Check point ...

Page 25: ...harmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 24 from 42 All GCPs will be shown on the map Select one GCP define position of ground control point at each image change type of GCP to 3D and setup horizontal accuracy to 50 meters ...

Page 26: ...ue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 25 from 42 Click Reoptimize button Click Ok on warning messages After finishing of reoptimizing process click Image property editor button ...

Page 27: ...g Page 26 from 42 Click Edit camera model buttons in Image Properties Editor window and in Edit Camera Model window Click Load Optimiezed parameters Copy Focal Length value for future work NOTICE It is possible to use the calibrated value of focal length for the processing If you don t change focus settings for future flights ...

Page 28: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 27 from 42 ...

Page 29: ... Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 28 from 42 3 4 Accuracy estimating Load ground control points Set up as check points Select position of all check points at images to check accuracy ...

Page 30: ... 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 29 from 42 Go to Processing option Select None for Internal Parameters Optimization Click Ok Click Reoptimize ...

Page 31: ...itzerland 41 797 910 713 info topodrone org www topodrone org Page 30 from 42 After finishing optimization process go to Process Menu click Generate quality report Data processing report will be generated Go to Geolocation Details to estimate accuracy of the project ...

Page 32: ...age 31 from 42 4 PHOTOGRAMMETRY PROCESSING IN AGISOFT METASHAPE SOFTWARE 4 1 Creating project photos alignment The following process should be performed in Agisoft Metashape Add photos to the project Import positions from file coordinates txt Go to Reference Click Import button select coordinates txt file from folder with photos ...

Page 33: ...witzerland 41 797 910 713 info topodrone org www topodrone org Page 32 from 42 Select WGS 84 coordinate system setup columns order 1 3 2 4 click Accuracy checkbox select field 5 click OK Accurate X Y Z coordinates and accuracy values will appear in Reference window ...

Page 34: ...y Switzerland 41 797 910 713 info topodrone org www topodrone org Page 33 from 42 Go to Tools click Camera calibration and input calibrated parameter for focal length 10 4777 select fixed F parameter Go to Workflow and click Align Photos for aerial triangulations ...

Page 35: ...ntre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 34 from 42 After finishing aerial triangulation go to Reference click Optimize Camera Alignment and click on Fit additional corrections check box Click OK ...

Page 36: ...www topodrone org Page 35 from 42 4 2 Accuracy estimating After finishing aerial triangulation go to Reference click Import and load GCP txt file Use the following settings and click OK Click Yes to All button GCPs will be shown at Model window Select locations of each GCP on photos and look at accuracy report ...

Page 37: ...Topodrone SA CHE 354 723 874 TVA Rue du Centre 39 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 36 from 42 ...

Page 38: ...ne org Page 37 from 42 4 3 Camera calibration To calibrate camera focal length load images import accurate coordinates of photos perform phots alignment don t fix F parameter and import GCPs Define position of markers on each photo Select 2 3 markers Click Optimize camera Alignment use the following settings and click OK ...

Page 39: ... 1637 Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 38 from 42 After finishing aerial triangulation go to Tools click Camera calibration Select adjusted and Save button Select Info Camera Calibration format and save file ...

Page 40: ...y Switzerland 41 797 910 713 info topodrone org www topodrone org Page 39 from 42 Open txt file and copy focal length value NOTICE It is possible to use the calibrated value of focal length for the processing If you don t change focus settings for future flights ...

Page 41: ... org www topodrone org Page 40 from 42 4 4 Aerial triangulation accuracy improvement Tie points filtering In order to increase an accuracy of your model we would suggest to filter tie points using Gradual Selection tool Open Model menu click Gradual Selection Select Gradual selection and input 0 35 value ...

Page 42: ...Charmey Switzerland 41 797 910 713 info topodrone org www topodrone org Page 41 from 42 Go to Edit menu and delete selected points Click Optimize Camera Alignment Check accuracy and repeat described above steps until Reprojection error reach 0 65 0 35 value ...

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