UgCS is a professional LiDAR flight planning software built by SPH Engineering. It includes dedicated LiDAR Area and LiDAR Corridor tools (available in UgCS EXPERT and ENTERPRISE licenses) that handle these variables for DJI, ArduPilot, and PX4 platforms. UgCS works with all major LiDAR sensors: DJI Zenmuse L1, L2, and L3, as well as third-party systems from Rock Robotic, YellowScan, Velodyne, RIEGL, and other sensors.
This guide covers how to plan LiDAR missions in UgCS from start to finish, including DEM setup, LiDAR drone settings, sensor-specific calibration workflows, and advanced parameters for terrain following and flight optimization.
The video walkthrough below shows the complete LiDAR mission planning workflow in UgCS.
Why DEM Data Is Critical for LiDAR Missions
LiDAR surveys depend on consistent altitude above ground. If the drone flies at a fixed altitude above sea level over rolling terrain, the distance between the sensor and the ground changes constantly. That means your point density varies across the dataset, your swath width changes, and you get uneven coverage. For terrain-following LiDAR missions, UgCS needs accurate digital elevation model (DEM) data to calculate waypoint altitudes.
Built-in vs. Custom DEMs in UgCS
UgCS ships with built-in elevation datasets, accessible through the Map Layers panel under the Elevation tab:
SRTM 1 arc-second (approximately 30 m resolution). This is the global default. SRTM (Shuttle Radar Topography Mission) data was collected by NASA in 2000 and covers most of the Earth's land surface between 60°N and 56°S. It is adequate for general terrain following over areas where the ground hasn't changed significantly since collection.
USGS 1/3 arc-second (approximately 10 m resolution). Available for the United States. This is three times more detailed than SRTM and is updated more frequently. If you are flying in the US, switch to this dataset for better terrain-following accuracy in digital elevation model drone mapping.
Custom DEM import. For sites where the default data is too coarse or outdated, you can load your own DEM in GeoTIFF format. Open the Map Layers panel, go to the Elevation tab, click the "+" button, and upload your file. UgCS will use your custom elevation data for all route calculations within that area.
Custom DEMs matter most in mining (where terrain changes between surveys), construction sites (active cut-and-fill operations), and forestry (where you may want a DSM that includes canopy height rather than bare-earth terrain). Accurate DEM data is the foundation of terrain-following LiDAR missions. The UgCS DEM system accepts any GeoTIFF, so you can use elevation data from a previous drone survey, national LiDAR datasets, or photogrammetry-derived surface models.
Creating a New LiDAR Mission in UgCS
UgCS supports drones from DJI, Freefly, and any platform running ArduPilot or PX4 autopilots. Here is the step-by-step LiDAR drone survey setup in UgCS.
Step 1: Create a new route. Click "Create new route" on the left panel. Choose "Create from scratch" or import boundaries from a KML or CSV file. KML/CSV import is useful when a client or GIS team provides the exact survey boundaries.
Step 2: Select your drone. Click "Next" and choose the drone platform. For this example, we select the DJI M350, but the workflow applies to any supported model.
Step 3: Choose the LiDAR route type. Click "Next," select "LiDAR," and then choose "LiDAR Area." UgCS also offers a LiDAR Corridor tool for linear features like powerlines, pipelines, and roads, but Area is the correct choice for surveying bounded zones.
Step 4: Draw the survey area. Hold Shift, click on the map to place polygon vertices, and press Enter to close the shape. UgCS immediately calculates the initial mission with flight lines, waypoints, and turn geometry.
Key LiDAR Flight Parameters Explained
LiDAR mission planning parameters differ from photogrammetry in several important ways. The overlap refers to the sensor swath rather than camera frames, IMU behavior affects turn design, and sensor-specific settings like field of view vary between models. Here are the best settings for LiDAR drone survey missions and what happens when each parameter is misconfigured.
Field of View (FoV)
The FoV angle must match your LiDAR sensor's specification. For DJI Zenmuse LiDARs (L1, L2, L3), the default is 70°. If you are using a third-party sensor, check the manufacturer's data sheet and enter the correct value.
What goes wrong if this is set incorrectly: If the FoV is set too wide, UgCS calculates wider line spacing than the sensor actually covers, which creates gaps between passes. If it is set too narrow, you get excessive overlap and waste flight time.
Flight Height and Speed
Set the flight height based on your required point density and the sensor's range specification. Most DJI LiDAR surveys fly between 50 and 100 m AGL. Lower altitude means higher point density but more flight lines and longer total mission time.
Flight speed defaults to 5 m/s. You can increase this to 8 m/s or higher for faster coverage, but check your sensor's maximum scan rate. Flying too fast at low altitude can result in gaps between scan lines within each pass. For DJI sensors at standard mapping altitudes, 8 m/s is typically fine.
Overlap and Line Spacing
You can set the overlap as a percentage or as an exact side distance in meters. A 20% overlap is a common starting point for LiDAR area surveys.
Important: This overlap value refers to the LiDAR sensor swath, not to the camera. The swath width is calculated from the FoV and flight height. If you confuse LiDAR overlap with camera overlap settings (which are typically 70-80% for photogrammetry), you will end up with far too many passes and unnecessarily long flight times.
Camera and Sensor Selection
This parameter depends entirely on which LiDAR system you are using in LiDAR drone setup:
DJI LiDARs (L1, L2, L3): Select the exact LiDAR model from the camera dropdown. This is required because UgCS uses the camera profile to configure recording actions and trigger parameters. If you leave this empty or select the wrong model, the LiDAR recording actions will not work correctly on DJI platforms.
Non-DJI LiDARs (Rock Robotic, YellowScan, Velodyne, RIEGL, etc.): Leave the camera field empty. These sensors record independently and do not need UgCS to trigger them. The LiDAR drone settings for recording are handled by the sensor's own controller.
Forward Overlap and Turns
Forward overlap controls how often the camera captures images (for colorized point clouds on DJI systems). The standard value is 80%.
The corner radius parameter is specific to LiDAR surveys. It controls the radius of turns at the end of each flight line. The default is 6 m, but increasing this to 15-20 m produces smoother, more rounded turns. Smooth turns matter for LiDAR because sharp direction changes cause accelerations that increase IMU drift errors.
For the turn type, set this to "Adaptive bank turn" for DJI drones. This keeps the drone moving continuously through turns instead of stopping and rotating at each line endpoint, which reduces IMU error accumulation and shaking of the LiDAR sensor.
Altitude Modes and IMU Calibration
AGL (Above Ground Level): The standard mode for terrain-following LiDAR surveys. UgCS adds waypoints where the terrain changes to keep the drone at the specified height.
Smart AGL: Recommended for steep terrain. Smart AGL considers the terrain ahead of the drone, not just directly below it. If your survey area includes cliff edges, quarry walls, or steep slopes, Smart AGL prevents the drone from getting dangerously close to terrain features it is approaching.
IMU Calibration checkbox: For DJI LiDARs (L1, L2, L3), keep this enabled. When checked, UgCS automatically adds IMU calibration segments to the route. These appear as blue-highlighted segments at the start and end of the mission, where the drone flies a 30 m straight line multiple times to calibrate the LiDAR IMU. For the L1, UgCS adds additional calibration segments every 100 seconds of flight. For the L2 and L3, calibration is added every 200 seconds. Every turn exceeding 10° resets the calibration timer.
On longer missions, UgCS also inserts calibration segments mid-route as needed. This automated calibration is one of the key advantages of dedicated LiDAR flight planning software over general-purpose flight apps, where pilots must execute calibration patterns manually (and inconsistently).
Required Actions for DJI LiDAR Missions
Open the Actions tab after creating your LiDAR route. UgCS adds one default action:
Set camera attitude: 90° downward. This points the LiDAR sensor straight down, which is the standard orientation for area surveys.
For DJI LiDARs, you need to add one more action manually:
Set camera by distance. This triggers the onboard camera at fixed intervals to capture photos for colorized point clouds. Without this action, you will get a point cloud with intensity values only (no RGB color), which is fine for some applications but limits your ability to visually interpret the data.
With both actions configured, the DJI LiDAR mission is ready to fly.
Planning LiDAR Missions with Non-DJI Sensors
LiDAR drone survey planning varies depending on the sensor manufacturer. If you are flying with Rock Robotic, YellowScan, Velodyne, or other third-party LiDARs, the setup differs from DJI in three main ways:
No camera selection needed. Leave the camera field empty. Non-DJI LiDARs record independently through their own controller.
No "Set camera by distance" action needed. Since the LiDAR handles its own recording, you do not need UgCS to trigger image capture.
Manual IMU calibration patterns. Non-DJI sensors do not use UgCS's built-in IMU calibration checkbox. Instead, you add calibration flight patterns to the beginning and end of your route using UgCS's dedicated calibration tools.
Calibration Pattern by Sensor
To add a calibration pattern:
- Select the calibration tool (figure-8 or U-shape) from the flight planning toolbar.
- Shift-click on the map to place the pattern at the start of your route, near the takeoff location.
- Repeat at the end of the route to add a closing calibration pattern.
UgCS positions the pattern as a distinct route segment. Make sure it is placed before the first survey line (for the opening calibration) and after the last survey line (for the closing calibration). Consistent calibration at both ends of the mission reduces IMU drift errors in the final point cloud.
Advanced LiDAR Mission Parameters
The Advanced tab contains parameters that refine data coverage and flight efficiency. These settings are especially important for large-area surveys and sites with complex boundaries.
Overshoot
Overshoot extends each survey line beyond the boundary of the LiDAR area. By default, this is set to zero, meaning the drone starts and stops recording exactly at the polygon edge.
Setting overshoot to 50 m, for example, means the drone flies 50 m past the survey boundary on each line before turning. This ensures you capture clean, usable data right up to the boundary edge, because the drone has already stabilized into straight flight before entering the survey area and hasn't started its turn yet.
You can also set a separate overshoot speed. Reducing overshoot speed to 2-3 m/s gives the drone more time to execute smooth turns, which further reduces IMU error at the line endpoints.
Area Buffer
Area buffer extends the survey coverage in all directions by a specified number of meters. Unlike overshoot (which only extends the individual flight lines), area buffer expands the entire polygon boundary.
Set the area buffer to 50 m if you need guaranteed coverage of the full site with some safety margin. This is useful when the exact survey boundary isn't precisely positioned, or when you need data slightly beyond the polygon edge for processing overlap with adjacent survey blocks.
The key difference: Overshoot extends the lines past the boundary. Area buffer moves the boundary itself outward. For most LiDAR survey drone planning, overshoot alone is sufficient. Use area buffer when you need data coverage beyond the original polygon in all directions, not just along the flight lines.
Elevation Profile and Terrain Following
The elevation profile is your primary tool for validating a terrain-following LiDAR mission before flight. Click "Elevation Profile" in the top tab to see the planned flight path overlaid on the terrain. Move your cursor along the profile and a red dot on the map shows the corresponding position on the route.
AGL Tolerance
AGL tolerance controls how closely the drone follows the terrain. A smaller value means more waypoints and tighter terrain tracking. A larger value means fewer waypoints and smoother flight, but the drone may deviate further from the target altitude over undulating ground.
For most LiDAR work, start with 3-5 m AGL tolerance. Decrease to 1 m if you need very tight terrain following (for example, forestry canopy mapping where consistent distance from the canopy is critical). Be aware that very low tolerance values generate many waypoints, which can reach platform limits on some autopilots.
Smart AGL for Steep Terrain
If the elevation profile shows the flight path getting dangerously close to the terrain at any point, switch from standard AGL to Smart AGL. Standard AGL only considers the ground directly below the drone. Smart AGL also considers the terrain ahead of the drone's flight path, which prevents the drone from flying into a cliff face or steep slope that rises sharply between waypoints.
Smart AGL is available in UgCS EXPERT and ENTERPRISE licenses. Use it whenever your survey area includes significant elevation changes relative to the flight line spacing.
Trajectory Smoothing
Trajectory smoothing eliminates unnecessary altitude changes caused by small terrain features. It has two sub-parameters:
Max slope (%). Limits how steeply the drone can climb or descend between waypoints. Setting this to 10% means the drone will glide over small dips and bumps rather than following every terrain variation. This reduces waypoint count, minimizes altitude adjustments, and saves battery.
Minimal gap (m). Tells UgCS to skip terrain gaps smaller than the specified size. If you set this to 100 m, the drone will fly straight over narrow valleys, ravines, or other terrain depressions shorter than 100 m rather than dipping down into them.
Both settings are especially useful for large-area surveys over terrain with many small features. Without trajectory smoothing, the drone constantly adjusts altitude, which wastes battery, increases flight time, and adds mechanical stress. With it, the flight path is smoother and the drone covers more area per battery.
LiDAR Mission Planning Best Practices
- Always verify your DEM before flying. Load the elevation profile and visually check that the terrain data matches the actual site. Outdated SRTM data can show terrain that no longer exists (or miss terrain that was added).
- Match FoV to your exact sensor model. A wrong FoV value cascades into incorrect line spacing and coverage gaps.
- Use overshoot of at least 20-50 m. This ensures the drone is in stable, straight flight when it enters the survey area and that line-edge data is usable.
- Enable IMU calibration for DJI sensors. There is no reason to skip this. Uncalibrated IMU data produces misaligned point clouds that are difficult or impossible to fix in post-processing.
- Add calibration patterns for non-DJI sensors. Place figure-8 or U-shape patterns at both the start and end of the route. Consistent calibration reduces drift errors.
- Check the elevation profile for terrain conflicts. Look for points where the flight path comes close to the ground. Switch to Smart AGL if needed.
- Consider flight speed vs. point density. Faster speed means lower point density per pass. If your project specification requires a minimum point density, calculate the maximum safe speed before setting this parameter.
- Plan for battery swaps on long missions. UgCS supports pause and resume from any waypoint. Identify natural break points (typically between survey lines) where you can land, swap batteries, and continue without coverage gaps.
Common Mistakes to Avoid
- Using photogrammetry overlap values for LiDAR. LiDAR swath overlap of 20% is typical. Setting 70-80% (as in photogrammetry) will double or triple your flight time for no benefit.
- Forgetting to select the DJI LiDAR camera model. Without the correct camera selected, DJI recording actions will not execute. You fly the mission, land, and discover no data was recorded.
- Flying without terrain following over uneven ground. AMSL mode at a fixed altitude over hilly terrain means your point density varies wildly. Always use AGL or Smart AGL for LiDAR.
- Skipping IMU calibration to save time. A 30-second calibration pattern at each end of the mission prevents hours of point cloud alignment work later. This is not optional for survey-grade results.
- Setting AGL tolerance too high. Values over 10 m mean the drone deviates significantly from the target altitude over terrain with moderate undulation. Start at 3-5 m and decrease if the elevation profile shows unacceptable deviation.
- Using a figure-8 pattern for YellowScan (or U-shape for Rock Robotic). Each manufacturer specifies the calibration pattern their sensor requires. Using the wrong one can produce poor calibration results. Check the table above.
Conclusion
Planning accurate LiDAR surveys takes more than drawing a box on a map and pressing fly. The quality of your point cloud data depends on decisions made during LiDAR mission planning: which DEM you use, how tightly the drone follows terrain, how IMU calibration is handled, and whether your LiDAR-specific parameters (FoV, line overlap, corner radius) match the sensor on your drone.
UgCS gives you direct control over all of these variables from a desktop interface, with dedicated LiDAR tools that automate the calculations and calibration workflows most flight apps leave to the pilot. The result is more consistent data, fewer re-flights, and less time spent fixing alignment errors in post-processing.
For photogrammetry-specific mission planning, see our companion guide on photogrammetry mission planning in UgCS. For more on UgCS LiDAR capabilities and supported sensors, visit the UgCS LiDAR software page.
Download UgCS to try the LiDAR tools.