5. Defining flight lines

This section describes how to use the basic features required for creating a simple flight plan.

Hint

To set general flight line settings, go to the Navigation bar Settings option and click Flight lines.

5.1. Selecting the sensor

MISSIONPLANNER uses the sensor parameters to calculate flight lines and trigger points.

Important

If you added multiple sensors to the project, select one from the secondary sidebar. The Basic metrics are updated accordingly.

5.2. Configuring flight line basic metrics

Important

Any parameters that you modify under Basic metrics are also modified in the Sensor settings.

In the secondary sidebar, under Basic metrics, configure the following parameters:

Parameter	Description
GSD	Ground Sample Distance - the distance on the ground that each pixel in an image represents (the physical size of one pixel in the real world). This option does not appear for LiDAR systems. Modifying the GSD adjusts the HAGL accordingly.
HAGL	Height Above Ground Level - the difference between the flight altitude and the terrain height. Modifying the HAGL adjusts the GSD accordingly.
Forward [min]	The minimal forward overlap between one image and the next along the flight line. Use this value to ensure the image sequence time is met, i.e. the camera has enough time (depending on the distance/flying speed) to capture each image in regard to its hardware capabilities. Hint The first parameter is the minimal forward overlap as a percentage. The second parameter is the minimal distance in meters between 2 image locations. In mountainous regions, you will need a low minimal distance to ensure that large variations in terrain over a small distance are captured.
Sidelap [mean/min]	The mean overlap between two flight lines. Hint The first parameter is the mean sidelap as a percentage. The second parameter is the minimal sidelap as a percentage. Modifying the Sidelap adjusts the Distance between flight lines accordingly.
Distance between flight lines	Use a specified portion of the stereoscopic area to calculate the distance to the next flight line. Modifying the Distance between flight lines adjusts the Sidelap accordingly.

5.3. Calculating altitude settings

In the secondary sidebar, under Calculate altitude from, configure the following parameters for the flying altitude and the rounding of the altitude.

5.3.1. Flying altitude options

Choose one of four distinct methods for the calculation of flying altitude.

Min. terrain Lowest terrain elevation
Max. terrain Highest terrain elevation
Mean terrain elevation Recommended in most scenarios
Terrain following mode Constant height above ground
Fixed altitude Enter value in [m] or [ft].

Altitude settings can also be adjusted in the general settings. There, it is possible to enable line stepping. However, that setting must be used with caution as it interferes with the min. HAGL!

5.3.2. Altitude rounding

At the bottom of the menu Calculate altitude from check the box Rounding and define in which unit ([m] or [ft]) and how flying height altitudes will be rounded:

up	round up applies the limits [0.5 , 1[
down	round down applies the limits [0.5 , 1[
next	rounds to next integer

5.4. Drawing a flight line

Important

Flight lines can only be drawn in areas for which elevation data has been downloaded. In the layers panel, make sure the layer containing elevation data encompasses your area of interest. If it doesn’t, navigate to and update the DTM data.

To draw a single flight line:

1. Before drawing a line, in the secondary sidebar under Calculate altitude from, select and/or check the following constraints:

   • Min. terrain

   • Max. terrain

   • Mean. terrain

   • Terrain following

   • Fixed altitude

   • Rounding

   Hint

   In areas with significant terrain variations it can be useful to have multiple flight line segments, each with a different elevation. Go to , select Flight lines and check the box Allow line stepping. Specify above which difference in height MISSIONPLANNER may apply line stepping automatically.

   

2. Click .

3. In the workspace, click the location where the flight line will begin.

4. Move the mouse to the location where the flight line will end and click again.

5. To continue drawing a new segment of the flight line, move the mouse as described in the above steps. Otherwise, perform a right-click.

   Hint

   If a buffer was added to the AOI, the flight line will extend to the buffer perimeters.

Flight line identification is based on two integer numbers (example: 35-2). The first represents the flight line and the second the segment (or part) of the flight line. It is possible to modify the IDs of flight line(s).

For wide area planning, all lines with a common first number are on a straight line.

Important

For various flight line modifications described in the following chapters, you can opt to alter either the entire line (comprising all segments) or a single segment.

Example

Copy line:	Copy segment:

5.5. Editing flight line(s)

To edit a flight line:

1. Click .

2. Select the required option from Select options.

   • Edit vertices of a single line and Move line parallel enable the modifications Fix azimuth and Fix height options under Modify options.

   • Single segment, Multiple segments and All segments enable all options but Fix azimuth and Fix height.

3. Select the Type by choosing Line or Segment.

4. Choose the desired unit m or ft.

5. Adjust the Modify options as required.

6. Apply the options that you modified as follows:

   • Edit vertices of a single line: left-click the line you want to edit.

   • Move line parallel: left-click the line and drag it parallel, then left-click again to finalize its placement.

   • Single line: left-click the line you want to edit.

   • Multiple lines

   default	SHIFT-pressed
   Left-click and drag the mouse across the lines you want to select for modification.	Left-click and drag the mouse to open a rectangle for the selection of lines.

   • All lines: click the workspace and in the message that appears, confirm that you want to continue.

5.6. Deleting flight lines

To delete flight lines:

1. Click .

2. Select the required option from Select options.

   • Single line: left-click the line you want to delete.

   • Multiple lines: left-click and drag the mouse across the lines you want to edit. Use the shift-pressed option to employ the rectangle tool. When you release the mouse button, the lines are deleted.

   • All lines: click the workspace and in the message that appears, confirm that you want to continue.

5.7. Setting a buffer around an AOI

It is recommended to add a good buffer around the AOI (minimally the surrounding flight altitude length), especially when planning an oblique mission.

To set a buffer around the AOI:

1. Click .

2. Enter the required buffer in meters.

3. Click the AOI that will be buffered.

   A new border (default color: yellow) appears around the AOI.

Important

While the AOI is selected

• it is not possible to draw lines outside the perimeter.

• every new flight line inside the AOI is extended to the border of the AOI.

5.7.1. Extending flight lines beyond the AOI

When adding flight lines, you can specify if and by how much the added flight lines will extend beyond the AOI. The chosen option will apply both to parallel added flight lines as well as flight lines manually drawn by the user. Be sure to select the AOI before adding new lines!

To extend added flight lines beyond the AOI:

1. In the menu select the Extend lines beyond AOI checkbox.

2. Select the required extension options:

   • In line direction - enter the maximum distance beyond the AOI in which the added line can extend in the same direction as the copied line.

   • Parallel to lines - enter the maximum distance beyond the AOI in which the added line can extend in parallel to the copied line.

   • Sensor Footprint based on HAGL - lines that you add will extend beyound the AOI according to the sensor footprint. This option also selects the above two checkboxes.

5.8. Adding flight lines automatically

Important

At least one flight line must be present before you can add additional lines automatically.

5.8.1. Copying a flight line

Important

You can specify if and by how much the added parallel flight lines will extend beyond the selected AOI.

To copy a flight line:

1. Click .

2. Choose Type Line or Segment.

3. Click Copy flight line.

4. Click Parallel copy.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new line (copy).

6. Click the flight line you want to copy (original).

7. Move the mouse up or down to the target location of the copied line and click the map to create the new line (copy).

To copy a flight line to a fixed distance from the original line:

1. Click .

2. Choose Type Line or Segment.

3. Click Copy flight line.

4. Click Parallel copy (2nd option) and enter the distance in meters that the new line will be from the existing line.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new line (copy).

6. Click the flight line you want to copy (original).

7. Move the mouse up or down to the target location (fixed distance) and click the map to create the new line (copy).

To copy a flight line in line with the original line:

1. Click .

2. Choose Type Line or Segment.

3. Click Copy flight line.

4. Click In line copy.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new line (copy).

6. Click the flight line you want to copy (original).

7. Move the mouse right or left to the target location and click the map to create the new line (copy).

5.8.2. Filling a shape with parallel lines

Important

You can specify if and by how much the added parallel flight lines will extend beyond the selected AOI.

To fill all of a selected shape with parallel lines:

1. Select the shape you want to fill.

   Hint

   At least one flight line must be present in the selected shape.

2. Click .

3. Click Parallel lines.

4. Click Fill whole selected shape.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new lines (copies).

6. Click the flight line you want to copy (original). The selected shape is filled with lines that are parallel to the line you selected.

To fill the selected shape to the left or right of an existing flight line:

1. Select the shape you want to fill.

   Hint

   At least one flight line must be present in the selected shape.

2. Click .

3. Click Parallel lines.

4. Click either Fill selected shape left of the line or Fill selected shape right of the line.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new lines (copies).

6. Click the flight line you want to copy (original). The “left” or “right” side of the selected shape is filled with lines that are parallel to the line you selected.

To add a fixed number of flight lines in the selected shape to the left or right of an existing flight line:

1. Select the shape you want to fill.

   Hint

   At least one flight line must be present in the selected shape.

2. Click .

3. Click Parallel lines.

4. Click Add lines and enter the number of lines you want to add in the Left and/or Right boxes.

5. Check the box use altitude from the reference flight line at the bottom of the sidebar to apply the flight altitude (not HAGL!) of the line you want to copy (original) to the new lines (copies).

6. Click the flight line you want to copy (original). The “left” or “right” side of the selected shape is filled with the number of lines you specified up till the AOI perimeter.

5.9. Breaking a flight line

Flight lines can be broken when it is necessary to change the image scale due to terrain. After a line is broken, each section is recomputed and gets its own flight height.

To break a flight line into two sections:

1. Click .

2. Set the required overlapping constraints (distance or images).

3. Click the flight line at the location where you want it to be slit into two lines.

5.10. Modifying the altitude of flight line(s)

To modify the altitude of flight lines:

1. Click .

2. Select the required option from Select options.

   • Single line - left-click the line you want to modify.

   • Multiple lines - left-click and drag the mouse across the lines you want to modify. Use the shift-pressed option to employ the rectangle tool. When you release the mouse button, the lines are modified.

   • All lines - click the workspace and in the message that appears, confirm that you want to continue.

3. Select the altitude units display to m or ft.

4. Select the update method:

   • Fixed altitude - sets the altitude to the value you enter.

   • Round altitude - rounds the current altitude to the nearest value you enter.

5.11. Modifying the direction of flight line(s)

To modify the direction of flight lines:

1. Click .

2. Select the required option from Select options.

   • Single line - left-click the line you want to modify.

   • Multiple lines - left-click and drag the mouse across the lines you want to edit. Use the shift-pressed option to employ the rectangle tool. When you release the mouse button, the lines direction are modified.

   • All lines - click the workspace and in the message that appears, confirm that you want to continue.

5.12. Setting the IDs of flight line(s)

To set the IDs of flight lines:

1. Click .

2. Select the required option from Select options.

   • Single line - enter the value of the new ID and left-click the required line.

   • Multiple lines - enter the values for the first new line ID and the increment by which to increase the ID of the other lines, then left-click and drag the mouse across the lines you want to renumber. Use the shift-pressed option to employ the rectangle tool. When you release the mouse button, the lines are renumbered.

5.13. Recalculating flight line(s)

The recalculation methods use the current Basic metrics displayed in the upper section of the secondary sidebar.

To recalculate flight lines:

1. Click .

2. Select the required recalculation method:

   • Recalculate whole flight line - only start and end points from the existing flight line are used to freshly calculate the flight line based on the current settings for:

     • Sensor

     • HAGL/GSD

     • Forward overlap

   • Recalculate image positions - flight line geometry remains the same. Only image positions are recalculated based on the current settings for:

     • Forward overlap

   • Recalculate footprints - only footprints between flight lines get newly calculated.

3. Select the recalculation method:

   • Single line - left-click the line you want to recalculate.

   • Multiple lines - left-click and drag the mouse across the lines you want to recalculate. Use the shift-pressed option to employ the rectangle tool. When you release the mouse button, the lines are recalculated.

   • All lines - click the workspace and in the message that appears, confirm that you want to continue.

Hint

This function can be a powerful tool if you want to make partial changes to the flight plan.

Example for adjusting the forward overlap of a single line:

1. Create all flight lines using parallel copy and the standard configuration.

2. In the Basic metrics section of the secondary sidebar, enter a new forward overlap value.

3. Recalculate image positions for one or more lines as described in the box above.