How to Plan Photogrammetry Missions in UgCS (Complete Guide)

UgCS is a professional drone flight planning and control application built by SPH Engineering. It supports DJI, ArduPilot, and PX4 platforms and includes a dedicated Photogrammetry tool that calculates flight lines, camera trigger intervals, and terrain-following waypoints based on your camera specs and desired ground sample distance (GSD). The Photogrammetry tool is available in UgCS PRO, EXPERT, and ENTERPRISE licenses.

This UgCS photogrammetry tutorial walks through every step of drone photogrammetry mission planning, from creating your first route to configuring advanced settings for stockpile measurement and 3D reconstruction. Each section covers both the how and the why, so the guide is useful for operators setting up their first drone mapping workflow and for experienced pilots fine-tuning repeat surveys. If you prefer video, the full walkthrough is embedded below.

Creating a New Photogrammetry Mission in UgCS

Setting up a photogrammetry mission in UgCS takes about two minutes once you know where everything is. Here is the step-by-step drone mapping route planning process in UgCS.

Step 1: Start a new route. Click "Create new route" on the left panel. You will see two options: create from scratch or import from a file. UgCS supports KML and CSV imports, which is useful if your survey boundaries come from a GIS team or a client's shapefile export. For this tutorial, select "Create from scratch."

Step 2: Select your drone. Click "Next" and choose your drone platform. UgCS includes profiles for DJI Matrice 350, M300, M600, M400, and many others, plus ArduPilot and PX4 autopilots. For this example, we select the DJI M350.

Step 3: Choose the route type. Click "Next" and select "Photogrammetry" as the route type, then choose "Area" on the following screen. UgCS also offers a Photogrammetry Corridor tool for linear features like roads, pipelines, and riverbanks, but Area is the right choice for surveying defined zones.

Step 4: Draw your survey area. UgCS prompts you to define the area on the map. Click to place polygon vertices, then press Enter to close the shape. The polygon does not need to be a rectangle. Irregular boundaries work fine, and UgCS will calculate flight lines to cover the full area.

Step 5: Select your camera. Open the camera dropdown and choose the payload you are using. In this example, we select the DJI Zenmuse H20. The camera selection matters because UgCS uses the sensor dimensions, focal length, and resolution to calculate GSD, frame size, overlap spacing, and trigger intervals. If your camera is not listed, you can add it manually (covered in the Drone Profiles section below).

Once you select the camera, UgCS calculates the route automatically: flight lines, waypoints, speed, trigger distance, and estimated flight time.

Step 6: Refine the area shape. After route calculation, you can still adjust the polygon. Drag any vertex to reshape the boundary. You can also drag the midpoints between vertices to add new points, which lets you trace complex site outlines without recalculating from scratch. The shape of your area directly affects coverage efficiency. A long, narrow polygon aligned with the flight direction will have fewer turns and shorter total flight time than the same area drawn as a wide shape with many short passes.

Reviewing Route Information and Flight Data

Before flying, check the two places where UgCS summarizes your drone mapping mission data: the Elevation Profile and the Route Log. Both help you catch problems before the drone is in the air.

Elevation Profile

Click "Elevation Profile" in the top tab. This window displays the drone's planned flight path as a line graph overlaid on the terrain below it. You can read the altitude at every waypoint, confirm that terrain-following is behaving as expected, and spot any points where the drone's altitude relative to the ground changes sharply.

The elevation profile also shows:

• Estimated flight time for the complete route
• Estimated flight distance across all passes
• Waypoint count (in our example route, 48 waypoints)

If the terrain varies significantly across your survey area and you are using AGL mode, the elevation profile is where you verify that the drone's altitude adjusts correctly. A flat line above uneven terrain means the drone is not terrain-following. You will want to switch altitude modes or check your DEM data.

Route Log

Open the route log by clicking the green checkbox on the route card. The route log provides a more detailed breakdown:

• Area and footprint of the survey zone
• Number of passes (survey lines)
• Number of waypoints
• Camera triggering by distance value and total shot count

The shot count is especially useful for estimating storage requirements and processing time in photogrammetry processing software. If a route calls for 1,200 images at 20 MP each, you know you need roughly 25 GB of card space and can estimate your processing workload in Agisoft Metashape, Pix4Dmapper, or whatever you use downstream.

Key Photogrammetry Mission Planning Parameters Explained

UgCS gives you control over six core parameters that determine data quality, flight efficiency, and compatibility with your processing workflow. Here is what each one does and how to set it for your UgCS photogrammetry mission setup.

Camera Selection

For drones carrying multiple payloads (like the DJI M350, which can mount two gimbals), you need to select the specific camera being used for photogrammetry. This is almost always the wide-angle camera. The camera profile tells UgCS the focal length, sensor width and height, and sensor resolution. UgCS uses these values to calculate everything else: GSD, frame dimensions, line spacing, and trigger intervals.

If the camera profile has incorrect sensor specs, every downstream calculation will be wrong. Before your first flight with a new payload, verify that the focal length, sensor dimensions, and pixel count match the manufacturer's data sheet.

Altitude: Flight Height vs. GSD

UgCS offers two ways to set altitude:

• Flight height (meters): You specify the exact altitude, for example, 50 m AGL. UgCS then calculates the resulting GSD based on your camera specs.
• GSD (cm/px): You specify the ground resolution you need, and UgCS calculates the required flight altitude automatically.

GSD mode is usually the better choice for photogrammetry mission planning because it ties your flight plan directly to the output resolution. If a client requires 2 cm/px orthomosaics for high-accuracy drone mapping, you set GSD to 2 and let UgCS handle the math. The relationship is straightforward: flying higher means larger GSD (lower resolution) but faster coverage; flying lower means smaller GSD (higher resolution) but more passes and longer flight time.

For reference, UgCS calculates altitude using the formula: height AGL = (focal length × GSD × sensor pixel count) / sensor dimension. It selects the minimum of the width and height calculations to ensure the specified GSD is met in both directions.

Flight Speed

Default flight speed for drone mapping missions is 5 m/s. You can increase it (for example, to 8 m/s) to reduce total mission time, or decrease it for higher image sharpness in low-light conditions. Higher speed means the camera trigger interval needs to be shorter to maintain forward overlap, so confirm that your camera's minimum trigger interval can keep up. Most modern DJI cameras handle 8 m/s without issue at standard mapping altitudes, but at very low altitudes with high overlap, you may hit the trigger rate limit.

Overlap Settings

Overlap determines how much each image shares with its neighbors in photogrammetry mapping. Two values matter:

• Forward overlap (along the flight line): The standard for photogrammetry is 80%. This means each consecutive photo shares 80% of its frame area with the previous image. High forward overlap gives your processing software more tie points to work with.
• Side overlap (between adjacent flight lines): The standard is 70%. This ensures neighboring passes share enough common features for the stitching algorithm to align them.

These 80/70 defaults work well for most mapping projects. You might increase overlap for complex terrain with dense vegetation (where feature matching is harder) or decrease it for flat, featureless surfaces like agricultural fields where processing is straightforward and you want to reduce flight time.

Turn Type

Set the turn type to "Adaptive bank turn" for DJI drones. This setting allows the drone to fly continuous curved turns between passes instead of stopping, rotating, and accelerating at each line end. The result is shorter total mission time and smoother flight behavior, which reduces the chance of motion blur during turns.

Altitude Modes

UgCS supports four altitude modes. Choosing the right one depends on your terrain:

• AMSL (Above Mean Sea Level): The drone holds a constant altitude above sea level. No terrain following. Use this over flat terrain where the ground elevation is uniform.
• AGL (Above Ground Level): The drone follows the terrain, maintaining a constant height above the ground. This is the standard mode for photogrammetry drone mapping because it keeps GSD consistent across the survey area. UgCS adds waypoints where the terrain changes to keep the drone at the specified height.
• Smart AGL: Available in UgCS EXPERT and ENTERPRISE licenses. Designed for steep terrain, such as cliff faces, quarry walls, or hillside vineyards, where standard AGL may not react quickly enough to rapid elevation changes. Smart AGL generates more waypoints to track aggressive terrain profiles.
• Rangefinder: For drones equipped with a downward-facing rangefinder sensor. Enables very low altitude flights (under 10 m) with real-time altitude correction. Useful for high-resolution inspection missions.

For most photogrammetry work, AGL is the right choice. Switch to Smart AGL when your survey area includes elevation changes that are steep relative to the flight line spacing.

Required Actions for Photogrammetry Missions

When you create a photogrammetry route, UgCS automatically adds two actions to every mission. You will find these in the Actions tab.

Camera attitude: 90° downward (nadir). This tilts the camera straight down, which is the standard orientation for orthomosaic generation. Nadir imagery produces consistent scale across the image and minimizes perspective distortion, which is critical for accurate area and distance measurements in the final map.

Camera trigger by distance. Instead of triggering at fixed time intervals, UgCS triggers the camera at fixed distance intervals calculated from your overlap settings and camera specs. Distance-based triggering is more reliable than time-based triggering in drone photogrammetry missions because it maintains consistent image spacing regardless of wind conditions or speed variations during the flight. If the drone slows down in a headwind, it still captures images at the correct spacing.

Both actions are calculated automatically. UgCS determines the trigger distance from the frame size and forward overlap percentage. You do not need to configure them manually unless you want to override the defaults.

Advanced Photogrammetry Settings for Better Accuracy

The basic single-grid nadir mission covers most drone mapping needs. But for applications that require measurement accuracy, like stockpile volume calculations, construction progress monitoring, or high-fidelity 3D reconstruction, two advanced settings make a significant difference.

Double Grid

Enable the "Double grid" checkbox in the Advanced tab. UgCS will calculate a second set of flight lines perpendicular to the first, covering the same area in a crosshatch pattern.

A double grid captures each point on the ground from two perpendicular directions. This gives your processing software more geometry to work with when reconstructing 3D surfaces, which reduces doming effects (a common error in single-grid datasets where the model curves slightly across the survey area). The tradeoff is roughly double the flight time and image count.

Oblique Camera Angle

In the Actions tab, you can change the camera tilt from 90° (nadir) to an oblique angle, such as 70°. Combined with a double grid, this means the drone captures every object from multiple directions at an angle, not just from directly above.

Oblique imagery dramatically improves the quality of 3D models. Vertical surfaces like building facades, retaining walls, or stockpile sides are barely visible in nadir imagery but clearly captured in oblique passes. For stockpile volume measurement, oblique double-grid missions typically produce more accurate results than nadir-only flights because the processing software can reconstruct the side slopes rather than interpolating them.

For operators who need oblique imagery but want to minimize flight time, UgCS also offers a Circlegrammetry tool. Circlegrammetry flies circular patterns with the camera facing inward at an oblique angle. Research from Dalhousie University found that it reduces flight time by 64% and processing time by 83% compared to standard oblique double-grid missions while maintaining comparable accuracy (1.38-1.53 cm RMSE).

Optimizing Takeoff and Return with Waypoints

Once you are satisfied with your photogrammetry mission parameters, the route is technically ready to fly. But adding a first waypoint and a last waypoint improves operational efficiency and safety.

First Waypoint

Select "Add first waypoint" from the toolbar and place it on the map near your planned takeoff location. UgCS does two things when you add a first waypoint:

1. It creates a transit segment from that point to the start of the photogrammetry area.
2. It automatically recalculates the photogrammetry grid so the drone enters the survey area from the corner nearest to the first waypoint.

This second behavior saves time. Without a first waypoint, the drone might fly to the far corner of the survey area before starting its first pass, wasting battery on transit.

Last Waypoint (Return Point)

After the photogrammetry area, add a standard waypoint at or near the takeoff location. This ensures the drone flies back to you after completing the survey instead of hovering at the last waypoint of the grid.

With both waypoints in place, the full mission looks like this: takeoff, transit to survey area, run all passes, transit back to the operator. You can verify this in the elevation profile, which will now show the transit segments at both ends of the route.

Using Custom DEM for Terrain Accuracy

UgCS uses digital elevation model (DEM) data to calculate AGL altitudes and terrain-following waypoints. The default SRTM data (approximately 30 m resolution) works for most areas, but it has limitations. SRTM dates from the early 2000s, does not reflect recent construction or earthworks, and its 30 m resolution can miss small terrain features.

If you need higher accuracy, you can load your own DEM.

To load a custom DEM in UgCS:

1. Open the Map Layers panel.
2. Go to the Elevation tab.
3. Click the "+" button.
4. Upload your DEM file in GeoTIFF format (.tif).

UgCS will use your custom elevation data for route calculation within the DEM's coverage area. This is especially important for mining surveys (where terrain changes between visits), construction site monitoring (where cut-and-fill operations alter the ground surface), and any project where the terrain has changed since the SRTM dataset was collected.

A high-resolution DEM from a previous drone survey (at 5-10 cm resolution) will produce far more accurate terrain-following than the default 30 m SRTM data. Some operators run a quick low-resolution mapping flight first, generate a DEM, then load it into UgCS for the high-resolution production flight.

Drone Profiles and Custom Payloads

UgCS ships with profiles for DJI, ArduPilot, PX4, and other drone mapping platforms. Each profile includes the drone's performance parameters (max speed, max altitude, turn radius) and a list of compatible payloads with their sensor specifications.

If your drone or camera is not in the default list, you can create or modify profiles in the Profiles section (accessible from the main menu). This is common for operators using third-party cameras on DJI Matrice platforms, or custom-built ArduPilot drones with integrated survey cameras.

When adding a custom payload for photogrammetry, make sure to enter accurate values for:

• Focal length (the true focal length, not the 35mm equivalent)
• Sensor width and height (in millimeters)
• Sensor resolution (horizontal and vertical pixel count)

If any of these values are wrong, UgCS will miscalculate GSD, frame dimensions, and trigger intervals. Your images will still be captured, but the overlap may not match what you planned. Double-check against the camera manufacturer's spec sheet.

The ability to create custom profiles is one of the reasons UgCS works across such a wide range of hardware. You are not locked into a single manufacturer's hardware lineup. The same software plans missions for a DJI M350 with a Zenmuse P1 and an ArduPilot hexacopter with a Sony A7R and a custom gimbal.

Next Steps

You now have everything you need to plan and configure a photogrammetry mission in UgCS. To recap the essentials:

1. Select the correct camera profile so UgCS can calculate GSD, overlap, and trigger intervals accurately.
2. Choose between GSD and flight height to set your altitude. GSD mode ties the flight plan directly to your output resolution.
3. Use 80% forward and 70% side overlap as a starting point, then adjust based on terrain complexity.
4. Set AGL altitude mode for terrain following, or Smart AGL for steep terrain.
5. Add first and last waypoints to control where the drone enters and exits the survey area.
6. Load a custom DEM if the default elevation data does not reflect current ground conditions.
7. Enable double grid and oblique camera angles when you need accurate 3D models or volumetric measurements.

For oblique photogrammetry with reduced flight time, explore the UgCS Circlegrammetry tool. For LiDAR-specific missions, UgCS offers dedicated LiDAR Area and LiDAR Corridor tools with IMU calibration workflows.

Download UgCS to try the Photogrammetry tool for free within UgCS Open.