Corridor Scan

A Corridor Scan is a mission plan for surveying roads, rivers and other path-like ground features. It creates a grid flight pattern that follows a poly-line.

A corridor scan mission must contain at least one Corridor Scan pattern.

The corridor is a path as highlighted on the map above. The white line indicates the grid flight path. The green circular markers indicate the points where the aircraft enters and exits the pattern.

The Mission editor on the right is used to set the corridor: width, altitude, required image resolution, and other properties, and to specify camera settings appropriate for creating geotagged images.

This topic shows how to define a corridor scan mission and the various settings that can be configured in the Corridor Scan Editor.

Create a Corridor Scan Mission

The corridor scan mission can be created under Plan view > Pattern > Corridor Scan from the Plan Tools.

This creates a template for a simple end end-to-end structure corridor scan mission for the aircraft. Often all the user has to do is define the scan area.

Any items that require configuration are shown with a red border in the mission item list.

If a more complex mission is needed, the basic mission can be extended by adding other items before the return item.

Steps to create a corridor scan mission:

1. Open the Plan View, select the Pattern and then Corridor scan.

   
2. Check that the Mission Start item settings are correct for the planned scan. In particular, the altitude is high enough to avoid obstacles when travelling to the corridor.

• The green part of the line is the area being scanned while the white line is the proposed flight path.

• Move a filled circle (vertices) at one end of the line to the beginning of the desired path, and the other to the end (drag/drop on the map).

• Select the unfilled circle between the two ends (vertices) to create a new vertex. Move the vertex to the first point in the path where the direction changes.

• Repeat the last step, creating new vertices and moving them onto the desired path.

Corridor Scan editor

The Mission _Editor_ is used to configure Camera and Grid settings. The bin icon on the top left can be used to delete the whole item.

1. Select the Mission tab to edit your Corridor scan pattern.

Set the camera first, before configuring the grid as the camera capabilities affects the grid settings.

Camera Tab

Users can select a predefined, custom, or manual camera. The main difference is that using a predefined or custom camera allows Mission Control to calculate an optimal layer height for a trigger distance, and visa versa, while using a manual camera means that these parameters need to be manually calculated (and are therefore harder to change).

The camera settings are exactly the same as for surveys and structure scans. For more information see: Survey > Camera.

Grid Tab

The Grid tab is used to set the properties of the scan.

For a predefined or custom camera the scan settings allow users to choose a desired image overlap and set either desired scan altitude or image resolution for the ground surface, which automatically calculates the other values.

Setting	Description
Overlap	Overlap between each image capture. This can be configured separately for when flying along grid lines (Front Lap) or across them (Side Lap).
Altitude	Survey altitude. The Ground Res field is dynamically updated with the resolution required for entered altitude.
Ground Res	Ground resolution for each image. The Altitude field is dynamically updated with minimum value to achieve the entered resolution

For a manual camera, the grid settings are instead specified as shown. Note that if any of these settings need to change, then they may all need to be manually recalculated.

Setting	Description
Altitude	Altitude to fly the whole path.
Trigger Distance	Distance over ground between each camera shot.
Spacing	Distance between adjacent grid (flight path) lines across the corridor.

Corridor Panel

The Corridor section is used for grid settings that are independent of the camera. Changes in the settings are reflected in the map.

Setting	Description
Width	Set the width of the scan around the polyline that defines the path.
Turnaround distance	Additional distance added to the outside the survey area for aircraft turn around.
Options	Images in turnarounds: Take images when turning/outside of grid. Relative altitude: Check to specify relative altitude (relative to home location). This is only supported for manual grids that are not using terrain following.
Rotate entry point	Button toggles (swaps) the entry and exit points of the scan.

Terrain Panel

Terrain Following makes the aircraft maintain a constant height relative to the ground throughout the survey. This is recommended when the terrain height varies a lot within the survey area.

By default, the aircraft will follow the survey path at a fixed altitude

Terrain following uses terrain heights queried from the AirMap servers.

Setting	Description
Aircraft follows terrain	Check to enable terrain following (and display the following options).
Tolerance	The accepted deviation in altitude from the target altitude.
Max Climb Rate	Maximum climb rate when following terrain.
Max Descent Rate	Maximum descent rate when following terrain.

Statistics Panel

The Statistics section shows the calculated survey area, photo count, interval, and resolution.