1. The Drone Harmony Flight Planning Workflow
Drone Harmony features a unique flight planning workflow called scene-based workflow. It consists of two main steps:
Scene creation: You outline, or import (or both) data about the inspected asset and its environment. The data becomes the internal Drone Harmony representation of your asset site, called a scene.
Automated Mission Planning: You select the asset to inspect/map and generate flight missions for this task using Drone Harmony’s automation algorithms.
You are free to make adjustments to the flight plans generated by Drone Harmony in either the web or mobile apps, using a multitude of intuitive tools.
The following are examples of scenes in Drone Harmony Web. A scene representing a collection of buildings:
A scene representing complex terrain and regions to be mapped:
2. Adding Polygons and Lines to the Scene
The Drone Harmony scene is the base of the mission planning workflow in Drone Harmony and setting it up is the first step in the workflow. Polygons and polygonal lines are an important basic primitive used in Drone Harmony to model assets and obstructions.
There are two basic ways of adding polygon and line primitives to the scene in both Drone Harmony Mobile and Drone Harmony Web: outlining using tools and importing from a KML/KMZ file.
The easiest way, and the one requiring no additional data files, is that of outlining a polygon, or line using a tool in the map interface. This is achieved by selecting the tool and then selecting the corner points of the polygon or line:
It is also possible to import polygons and lines using a KML/KMZ file. The file can contain any number of polygons and lines and it is possible to import any number of files into one state:
Recall that you can give polygons the third dimension to model buildings, no-fly zones, obstructions and other vertical primitives:
3. Useful tools for flight plan creation
Selection tools
The Lasso tool was designed to conveniently choose any object/element that you can create in Drone Harmony including areas, mission plans, single waypoints, lines, etc.
You may choose objects with this tool for deleting, editing, or reshaping them.
2D polygons (i.e. areas) creation
To create a 2D polygon for flight planning, choose the `Create polygon/building` option from the area creation tools in the left-side toolbar. Also, Drone Harmony will allow you to import the KML/KMZ file that contains the area.
2D lines creation
2D lines were designed to mark any linear infrastructure like pipes, roads, etc. for flight planning and inspection purposes. To create it you should proceed to area creation tools in the left-side toolbar and choose option ‘Create line’.
Points of Interest (POIs)
Points of interest (POIs) are points in space designed to mark landmarks in the scene. POIs can be created using the POI tool in map and 3D views. Selecting POIs in 3D view is possible by clicking on a point on the point cloud.
The main function associated with POIs is the direction of the drone cameras at the POI at any chosen waypoint. To direct the drone camera at the chosen POI:
choose the waypoint(s), e.g., by using the lasso tool in Map or 3D views.
Navigate to the Waypoints Edit menu and choose “Direct at POI”
Choose the POI in the drop-down list
3D Polygons (i.e. buildings)
Creation of complex 3D structures in Drone Harmony could be achieved by providing your 2D polygon (area) a height by right-clicking on the polygon or by using the building import feature. It will allow you to import georeferenced 3D models of buildings in places where the data is available.
4. The Automated Flight Plan Catalog
The plan catalog includes a collection of patterns that you can apply to generate missions for assets in your Drone Harmony scene. Although they share a lot in common, the missions in the plan catalogs in Drone Harmony Mobile and Drone Harmony Web are different. The exact missions available depend on what types of scene can be created in each interface. For example, for working with large terrain models, the ability to upload and manage terrain files in Drone Harmony Cloud through the web browser is needed. Thus, most terrain aware flight planning is only available in Drone Harmony Web.
The missions in the plan catalog are typically sorted in tabs according to application domain (e.g. Mapping, Perimeter, Inspection etc.) and by data type (e.g. Terrain). Thus, if you would like to plan a terrain-aware mission for the terrain data loaded in the scene, you should use the “Terrain” tab and pick a mission from there.
6. Terrain Aware Planning
Terrain-aware flight planning is a way to use terrain models to adjust drone flight plans. Using terrain-aware planning is particularly important when the flights are performed in areas with significant elevation changes, such as in the mountains, or on industrial sites, such as open pit mines.
It is also important to use terrain when inspecting or mapping very large assets, as small changes in the terrain accumulate to large overall changes across large distances.
Typical use cases for terrain-aware flight planning include mapping and inspection of mines, linear infrastructure (such as power lines, railroads, etc.), precision agriculture, and more.
7. Hill Scan: Mapping of Complex and Steep Terrain
One of the most unique features of Drone Harmony Web is Hill Scan – an automated flight mission that allows you to inspect and map very complex and steep terrain. Hill Scan is a powerful and very flexible plan that is useful in various use cases including:
When the terrain to be inspected is very steep (even vertical), e.g. when it represents cliffs, rock walls, steep hills, or even structures, such as dams.
When the terrain profile is very non-uniform, e.g. hills, mountain peaks, canyons, and valleys, or combinations of flat and steep sections of a landscape.
When it is important to direct the camera perpendicularly at the terrain surface.
Planning a Hill Scan mission works like planning any other terrain-aware mission. You will require a terrain and at least one polygonal area in your scene to plan the mission for. The parameters to set are distance to surface (determining the Ground Sampling Distance), overlap parameters, and camera settings. All other attributes of the missions are set automatically by Hill Scan to achieve ideal results.
Hill Scan vs. Terrain Following
What is the difference between terrain following and Hill Scan?
Traditional drone mapping surveys, including terrain following such as Terrain Map, rely on grid missions, which cover the area of interest with nadir images placed on a grid. The spacing between adjacent images is chosen to match an overlap parameter, and the flight altitude is selected according to the desired ground sampling distance (GSD – determines what area of the surface is represented by each pixel in the image). Compared to a standard grid mission, Terrain Following improves the acquisitions by adjusting the height of the flight to the local profile, which ensured a fixed GSD, but does not ensure overlap consistency, nor does it adjust camera angles to the terrain slope. Drone Harmony’s Hill Scan solves all these issues. The following figure gives a visual comparison between the three methods and summarizes their properties.
Another valuable attribute of Hill Scan is its flexibility. One can use Hill Scan to map a larger area with varying elevation profiles, without the need to split the region into regions that are coherent in terms of slope or azimuth. As a result, hilly areas can be mapped in combination with flatter areas all in one contiguous mission. In summary, Hill Scan is a powerful tool that can assist in a variety of inspection activities, such as cliff stability assessment, mine site inspection, dam inspections, and more.
8. Panorama Missions
A waypoint mission in Drone Harmony can contain an arbitrary combination of regular and panorama mission waypoints.
Note that Drone Harmony can be used to collect the image set for creating a panorama, but it currently does not combine them into a panorama image. Other applications should be used to achieve this based on the collected data.
Planning in DH Web
Here is how to create a panorama mission from scratch. Click on the blue + at the bottom right and select “Manual” / “Manual WPS”. Create a manual flight plan. Right click on a waypoint and select the option “Convert to Panorama”. You may also select several waypoints (with shift / ctrl or the selection rectangle tool) and convert them into panorama waypoints. The 3D view illustrates your planned panorama mission clearly:
Planning in DH Mobile
Click on the blue + at the bottom right and select “Manual” / “Manual WPS”. Create a manual flight plan. Long click on a waypoint in order to select the option “Convert to Pano”. You may also select several waypoints (lasso or quick clicks on waypoints, not on lift-offs or landings) and convert them into panorama waypoints. The 3D view illustrates your planned panorama mission perfectly.
Converting waypoints into panoramas
Any waypoint in any mission can be converted into a panorama using the workflow described above.
Customizing the Panorama Mission
In DH Web you have the option to customize your panorama image set. To do so, use the option “Customize” after selecting the waypoints to convert and choosing “Convert to Panorama”. Fill in short form following the instructions.
The settings chosen in the Panorama Customization Form are saved and will later also be used to generate panoramas in DH Mobile.
Flight Safety
Note that all missions that contain Panoramas will automatically be executed in the Virtual Stick flight mode, which requires continuous radio signal during the automated flight.
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