Remote Drone Mapping on Grand Mesa, Colorado

JP Uncategorized

Remote Drone Mapping on Grand Mesa, Colorado – Labor Day – September 4th, 2017
Pierre Stoermer, CEO – DroneMapper.com


Delta County, Colorado agriculture has the benefit of over 300 reservoirs on the Grand Mesa, many of which supply irrigation to the variety of crops grown. This time of year, the reservoirs are being drawn down providing an excellent opportunity to map and determine reservoir capacities.

We had the opportunity to pack up our UTV with the DJI Phantom 3 advanced drone, gear, lunch and head on out to the Leroux Creek area of the Mesa. It is approximately 12 miles on Forest Service roads and 50” doubletrack to access the watershed from the Surface Creek trailhead (map shown below).



Access to some of the remote lakes between 10,000 and 11,000 feet elevation can be difficult so our Wildcat is equipped with Stihl MS200T chainsaw, Pelican dust-proof drone case, extra fuel and Warn winch.



The next few shots show the beautiful Mesa country on the way to Leroux. Half the fun is getting there!



On this trip, we pre-planned and cached the missions for 3 reservoirs including Lucky Find reservoir which was drained to the deadpool. There is no cell or internet connectivity in the Mesa backcountry so we need to have a reliable remote location programming capability. We utilized MapPilot 1.5.0 for our mission planning and execution application. The screenshot illustrates the mission plan for Lucky Find utilizing 80% image overlaps flying at an elevation of 300’ above ground. Image collection for the lake area was estimated at 150 images requiring 11 minutes of flight time.



The next picture is of Lucky Find drained down to the deadpool.



Phantom 3 has been fully programmed and ready to launch for the mapping mission.



DroneMapper’s REMOTE EXPERT Windows application was used to generate the DEM and ortho from the image collection. Screenshots of the DEM and orthomosaic follow. REMOTE EXPERT generated the data products within one hour on our laptop, allowing processing in the field and mission verification prior to pack-up.



Global Mapper was then used to construct 1’ interval elevation contours as shown below:



Each contour is selected individually and a flat elevation surface created to compute the reservoir volume and surface area associated with the selected contour. This is repeated for the elevations of interest from the deadpool up to the elevation where dam spill occurs to determine reservoir maximum capacity. The blue dotted contour shows maximum capacity prior to drainage at the spillway on the southwest side of the reservoir.

It is critical that the drone firmware and the mission application be thoroughly tested before departure to remote locations where no communications exist. If you need assistance for end-to-end mission planning and execution please do not hesitate to contact us.


Phantom 3 Advanced Firmware: 1.8.10
MapPilot Version: 1.5.0 build 031916
DJI Go App Version: 2.8.6
Ipad Mini4 iOS Version: 9.3.3
Remote Expert Version: v0.8 b20170829-842 x64
Global Mapper Version: v18

Thank you, The DroneMapper Team

RAPID – New Release of the Free Imaging Processing Application

JP Uncategorized

RAPID – New Release of the Free Imaging Processing Application, August 31, 2017
Pierre Stoermer, CEO – DroneMapper.com

 



DroneMapper has just released a new version of RAPID, formerly known as RAPID for DJI. This free
photogrammetry application has been modified to work with any camera sensor or UAV platform — where before it only
processed imagery from DJI cameras. It still does, but this version can be used with any non-DJI sensor as
well, including large format compacts and DSLRs, multi-spectral-multiple aperture sensors and thermal
sensors. If the sensor to be processed is not in the existing RAPID camera catalog or automatically detected then the user merely
specifies the focal plane height and width in millimeters to utilize existing camera calibration algorithms.
Features include:

  • Up to 150 JPG image input,
  • Low resolution DEM (X8) and Ortho (X4) output in GeoTiff format,
  • Geo-referenced output products in UTM WGS84 coordinates,
  • Low-latency preview Ortho generation for field verification of imagery collection,
  • It’s free – use it for personal or business applications.

Thank you, The DroneMapper Team

Drone Mapper Deploys New Features, 3D Model Processing, NDVI, 150 Images for DJI, and more.

JP Uncategorized

Drone Mapper Deploys New Features, 3D Model Processing, NDVI, 150 Images for DJI, and more.
JP Stoermer, CTO – DroneMapper.com

 


You can now process up to 150 images from DJI sensors for free on your Windows 10 desktop. We've also added NDVI calculations and a load of other new features to the software. Drone Mapping made easy.

Download the latest version at the following link: https://dronemapper.com/software_downloads/
Changelog: https://dronemapper.freshdesk.com/solution/articles/2100019927-dronemapper-changelog
Example data here: https://dronemapper.com/sample_data


Pix4D example data (used for processing tests): https://support.pix4d.com/hc/en-us/sections/200591139-Example-Datasets-Available-for-Download#gsc.tab=0

April 13th, 2017 – v0.7 b20170413-735

  • Added functionality to export .txt file(s) containing Omega, Phi, Kappa, X, Y, Z orientation (relative and world positions)
  • Overnight mode, run all processing steps automatically
  • Various UI tweaks and bug fixes
  • Increased free DJI processing limit to a maximum of 150 images
     

February 12th, 2017 – v0.7 b20170212-712

  • Add NDVI generation option, creates ENDVI and NDVI from NIR orthomosaic (REMOTE, EXPERT only)
  • Add image EXIF pre-processor, metadata generator
  • Additional, improved blending for orthomosaic (REMOTE, EXPERT only)
  • Improved UI feedback from backend API, display dm3d current task count/status
  • Improved logging
  • Processing speed improvements
  • Fixed bug with DEM scaling and certain AGL EXIF tagged data collections
  • Add DSM/hillshade generation option, creates gray scale DSM render from DEM (EXPERT only)
  • Add support for FLIR Vue Pro thermal cameras (JPGs)
  • Preserve ortho preview / geo-reference results, no need to re-run once completed
 


Thank you, The DroneMapper Team

Build an Enhanced and Traditional NDVI with DroneMapper and Global Mapper

JP Uncategorized

Use this workflow to process aerial UAV imagery with DroneMapper and Global Mapper to create an Enhanced and Traditional NDVI. These steps assume you are working in a licensed version of REMOTE or REMOTE EXPERT. We recommend using Map Pilot or DJI GS Pro for initial data/imagery collection and flight planning.
 

Global Mapper: http://www.bluemarblegeo.com/index.php

MaxMax Camera: http://maxmax.com

DroneMapper: https://dronemapper.com/software_downloads

 

  • Open DroneMapper and navigate to a NIR imagery collection

  • Navigate to the "DroneMapper Processing" tab and click the settings icon, enable NDVI creation, start the processing

  • Once processing has completed for the DEM and Orthomosaic, the Enhanced and Traditional NDVI files will be created.

    For more information on NDVI formula's please visit the following: http://www.maxmax.com/endvi.htm

    The traditional NDVI formula uses the blue channel for the NIR because the Kodak had created a special kind of color infrared film where the blue crystals could respond to blue or infrared light while the red and green crystals only responded to visible light.  By using a visible blue light blocking filter, the user could capture an image where Blue = NIR, Green = Visible Green, and Red = Visible Red.  The red channel was used instead of the green since the green channel would also reflect light while the red channel absorbed light when taking pictures of plants.   The key is that you need a NIR plant reflective channel and a visible plant absorption channel.

     

    Digital cameras respond different than film.  The main thing to understand is that you want the camera to have near infrared and visible bands in separate channels.  Once you have the NIR isolated in a color channel, you can perform NDVI type measurements.   With our NDVI cameras, the blue and green channels see visible light while the red sees the NIR.  Thus, the NDVI formula can be re-written for these cameras as:

    The blue channel for our NDVI can be used equally as well for the visible absorption channel as the Kodak film used the red as the visible absorption channel.

     

    We have found that you can get even better results if you use the red and green as the reflective channels while using the blue as the absorption channel.  Remember that a normal healthy plant will reflect both visible green light and NIR light.  We can improve on the NDVI formula for these cameras by changing the formula:
     

     

    This ENDVI formula sums the NIR and Green channels together for the reflective channel.  The Blue channel is multiplied by two to compensate for the NIR and Green channels being summed together.
     

  • You can new view the ENDVI or NDVI in Global Mapper to perform zonal statistics/pixel calculations/etc

Build a bare earth DTM from UAV imagery with DroneMapper, LAStools and Global Mapper

JP Uncategorized

Use this workflow to process aerial UAV imagery with DroneMapper, LAStools and Global Mapper to create a bare earth DTM (Digital Terrain Model). These steps assume you are working in a licensed version of REMOTE or REMOTE EXPERT. This is an advanced tutorial and requires software installation, post processing and command line work. We recommend using Map Pilot or DJI GS Pro for initial data/imagery collection and flight planning.
 

LAStools: https://rapidlasso.com/lastools

DroneMapper: https://dronemapper.com/software_downloads
Global Mapper: http://www.bluemarblegeo.com/index.php
 

  • Open DroneMapper and navigate to imagery folder location:

    In the example above we've opened 157 DJI images inside of REMOTE EXPERT for Digital Elevation Model, DSM, Point Cloud and Orthomosaic generation.

  • Navigate to the "DroneMapper Processing" tab inside the application and click the "Settings" icon. Enable the "Generate ASCII PLY/XYZ Point Cloud (64bit)" option.

    Close the settings dialog and activate "PREVIEW" step processing.

  • The screenshot below shows the "PREVIEW" step running with the EXIF stage completed and the FEATURES stage in progress.

  • NOTE: The "PREVIEW" step can take a good amount of time to complete depending on the number of images, image resolution, image megapixel, etc. If you are concerned that no progress is being made, please check the task manager and/or refer to the DroneMapper API status output inside the application. If you are checking progress via task manager, you should see a number of "dm3d.exe" processes. In this example, 3 API processes are shown as I am working from my old 2011 DELL XPS15Z (4 core).

     

  • Once the "PREVIEW" step is completed the grey scale orthomosaic is displayed on the "Map" tab. Additionally, you will have a new folder inside the original imagery folder named "DrnMppr3D". This folder is where the output GeoTIFF and Point Cloud results are stored after each step of processing is completed.

    You can enable one of the included map base layers to quickly check the geo-referencing of the data collection and orthomosaic processing.

    For this 157 image example from a DJI Phantom 4, I was able to generate the PREVIEW results in 22 minutes.

  • Next, navigate back to the "DroneMapper Processing" tab and activate step 2 (digital elevation model) processing. In this example, I am not processing at full resolution or using the "Dense" option for digital elevation model generation.

  • Once the digital elevation model has completed processing it will be displayed on the "Map" tab. Additionally, the GeoTIFF results will be available in the "DrnMppr3D" folder.

  • Activate step 3 and Orthomosaic generation. Once completed, the Orthomosaic and Point Cloud will be available in the "DrnMppr3D" folder.

    NOTE: Much of the workflow beyond this point requires installation of LASTools and Global Mapper. It also requires use of the windows command line. Installation and operation of LAStools and Global Mapper is outside the scope of this document.

  • Navigate to the "DrnMppr3D" results folder from the recently processed data collection. Hold down the SHIFT key and click your right mouse button, choose "Open command window here".

    Now you have a DOS command window open in the correct folder where the Point Cloud is located.

  • Execute "lasground.exe" to classify DroneMapper Point Cloud results. (Please see LAStools license here: http://www.cs.unc.edu/~isenburg/lastools/LICENSE.txt)

    NOTE: You will need to research and adjust the lasground.exe command line parameters to filter points to your liking.
     

    C:\Users\stoermer\Desktop\test-imagery\dji-ra-157\DrnMppr3D>c:\dev\LAStools\bin\lasground.exe -i PLY-DroneMapper.ply -ultra_fine -step 15 -odix _g -olaz -spike 1
    Please note that LAStools is not "free" (see http://lastools.org/LICENSE.txt)
    contact 'martin.isenburg@rapidlasso.com' to clarify licensing terms if needed.
    processing file 'PLY-DroneMapper.ply'.
    horizontal units are meter and vertical units are meter. custom mode.
    reading 2825734 points. step is 15 m, sub is 8, bulge is 3 m, spike is 1+10 m, and offset is 0.05 m ...
    took 22.776 sec. finding initial ground points ...
    took 0.122 sec. generating initial ground estimate ...
    took 0.085 sec. refining ground ...
    took 0.577 sec. adding terrain features ...
    took 7.721 sec. integrating points 0.05 above ground ...
    took 6.144 sec. outputting ...
    WARNING: unlicensed. over 1.5 million points. output slightly distorted.
             tiny xyz noise. points permuted. intensity, gps_time, user_data & point_source_ID zeroed.
    took 8.953 sec. 2599591 points classified as ground.
    done with 'PLY-DroneMapper_g.laz'. total time 46.382 sec.
    
    C:\Users\stoermer\Desktop\test-imagery\dji-ra-157\DrnMppr3D>

     

    Once "lasground.exe" has completed you will notice a newly created file located in the "DrnMpp3D" folder. The file is named "PLY-DroneMapper_g.laz".

  • Next we load "PLY-DroneMapper_g.laz" in Global Mapper 18, making sure to set the correct projection and point filtering options.

    Below is the bare earth filtered point cloud viewed in Global Mapper 18.

  • Loading the "Ortho-DrnMppr.tif" file from the "DrnMppr3D" folder is a good way to visualize what has been filtered from the initial point cloud and digital elevation model.

  • If you are happy with the filtered results, next generate an elevation grid inside Global Mapper from the bare earth point cloud.

  • Once the GRID generation is completed you have a bare earth DTM which can be exported as a GeoTIFF or any other elevation format via Global Mapper: