Drone Mapping
Contents
Terms
- SPC (State Plane Coordinate System) - mapping projection that mimizes distortion [1]
- These are expressed in ASCII feature, point, X, Y, Z location. [2] (raster)
- UTM - Universal Transverse Mercator projection [3]
- File types used in satellite mapping - [4]. Application/geo+json is used by GIS?
- File formats are mainly raster or vector [5]
- 20 commonly used file formats exist for GIS software. Open and proprietary, hybrid (owned by a a company but open). Text files include XML, JSON
- Files openable by QGIS - vector data, in various containers. Can be text, can be ESRI Shapefile, etc. [6]
- SPC format is
Missouri SPC Dataset
(other states should be available)
- Link - [7]
- Download is in .sid [8] format and is 10Gig for North Missouri
- To load in QGIS - download QGIS or use OSE Linux
Missouri Howto
- You can download the dataset and view it in QGIS
- Download is .sid.
- MrSID support on Linux Mint 20 doesn't appear to exist. This is the instructions - but no downloads of MrSID show up [9]
Howto - Overlay of Raster Image onto QGIS
You can download county-wide imagery from the 2022/2023 dataset from MSDIS (https://msdis.maps.arcgis.com/apps/View/index.html?appid=5490021931814fd9a64ba6f1468fa9f0&extent=-101.2474,34.3685,-82.7904,42.2591). You’ll need to have the `MO 2022-2023 North Imagery Index` box selected, and be sure to not zoom in too far or the download option for that dataset will disappear. Download option will appear when you click on the map for the county of interest. SPC and UTM options are available, both are in .sid raster format. Note: Import .sid Into Linux Mint
View-only imagery is available from ESRI (https://www.arcgis.com/home/webmap/viewer.html). You’ll have to select either `Imagery` or `Imagery Hybrid` on the Basemap panel.
Other imagery (going back in some areas to the 1940s) can be downloaded from Earthexplorer.usgs.gov
I would suggest QGIS as a good software option for handling georeferenced imagery. The downloadable imagery above, and possibly the photos coming out of your drone, are georeferenced, so will all automatically appear in the proper location in QGIS instead of manually having to overlay them. Any images that are not natively georeferenced can be manually georeferenced. Then you can easily measure distances, draw additional layers, etc. Using QGIS, you can also add the 6-in resolution imagery as a streaming service by adding https://moimagery.missouri.edu/arcgis/services/Statewide/Missouri_6inch_12inch_North_2022_2023_Detail/ImageServer/WMSServer as a WMS server. You can also ask your surveyor for a georeferenced PDF of your survey drawing and/or a shapefile set of the boundary, which can both be opened in QGIS and located in the proper place rather than trying to manually overlay everything.
- If you just navigate to the WMS Server URL in a browser, that is the message you get. You'll need to enter that URL in the QGIS dialogue box when adding a new WMS/WMTS Server layer
Point Clouds and Photogrammetry
.
I'm sure you're aware, but QGIS is an open source software. There are a huge number of 3rd party plugins available -- it would likely be worth exploring those to see if any might fit your future needs.
Another open source tool that I've used in the past for drone image processing is WebODM (https://www.opendronemap.org/). I've used its photogrammetry capabilities to generate both a 3D point cloud and raster DEM from a collection of drone images.
DJI Mini
- Mini data can be processed in DroneDeploy to create maps - [10]
Other
Open source path generation and datapoint visualization from IRNAS.
https://www.irnas.eu/iot-drone-mapping/
