Aerial Mapping with Copterus App

Copterus App can be used to capture aerial images for further processing to get high-resolution 2D orthomosaic and 3D map models (surface, terrain, elevation models, point cloud, textured mesh etc). More details on what 3D mapping is and why you need it. The whole process can be divided into following steps:

  1. Plan a flight

  2. Fly

  3. Process imagery



Plan a flight

Create new mapping mission


Tap on main menu button and select + New mission

Create new mission

Move map to desired location or use search field to find one, then tap Create here button. Next, choose Survey grid and tap Create.

Create new mission

This will create a polygon template, which you can adjust to fit your area. When you are done with polygon, tap Done.

Edit survey polygon

Tune your mission


Now it's time to tune your mission. Look at the info panel at the top. Here you have GSD (Ground Sample Distance) in cm/pix (or inches/pix for imperial unit system), area of the polygon in hectares (or acres), flight route distance in kilometers (or miles), number of photos the selected (or connected) drone will take, estimate flight time and needed number of batteries to fly the mission. Each of these values depends on some mission parameters, camera and drone characteristics.

Mission values

GSD depends on flight altitude and camera sensor resolution. That is how many centimeters (or inches) on the real ground fit in one sensor pixel. The lower the GSD value the higher resolution you get on your imagery. Typical GSD for most cases is 5 cm/pix (2 in/pix). 1-2 cm/pix (0.4-1 in/pix) is considered hi-res map.

Lower altitude and/or use drone with higher resolution image sensor to lower GSD (and thus to increase image detalization).

But lowering altitude leads to narrowing width of the visible terrain, thus it needs more images to fully cover desired area.

This increases flight route length, flight time and number of photos to process.


Area is just calculated polygon area.


Route length depends on images side overlap and altitude


Number of photos and Flight time depends on route length, images front overlap and image format.

DJI cameras need more time (up to 10 sec) to process single RAW image compared to 1-2 sec for JPEG image.

Thus, if there is low altitude and high front overlap (photo position close to each other) a drone needs to fly slower to have time to process RAW images before it gets to the next photo position.


Number of batteries is an estimate calculation of mission flight time divided by average drone's flight time on a single battery.


Set desired altitude and tune other mission parameters:

Tune mission parameters

Select Grid if you are going to get 2D orthophoto results from your imagery data or Double Grid to process for 3D models. Double Grid option adds a 90-degree cross-route.


Set front and side overlaps according to your image processor software requirements. Typical values are 50-70% for front overlap and 70-75% for side overlap.

The greater overlap you set, the greater quality you'll have from image processing tool, but greater overlap leads to increased flight route length and number of images to take and process.

As described above, RAW file format option will force a drone to fly slower between points to have time to process and save an image shot. Selecting option in this menu is only used to set max flying speed and calculate estimate flight time and will not influence the camera settings. If you set JPEG option here and RAW option in camera settings, then you will probably get missing photos at some positions.

You can also set flight direction according to wind, sunlight, shadows or other reasons. For your convenience, the direction can be set by stepper or

by rotating the route with two fingers.

Set route direction

Choose drone and camera to fit best


If you have drone connected at this moment, the flight route will be calculated according to the detected camera model.

With drone disconnected, you can select one by tapping camera button at the bottom.

In My drones section you will find the drones previously connected to the app. DJI drones section contains all supported DJI drones.

For those copters with interchangeable cameras you can select a drone first and then a camera.

Choose drone
Note for zoom cameras: if you select a zoom camera, the route will be calculated assuming zoom is to be set at minimum (1x, widest field of view).

Start point


It's possible to reverse or/and mirror calculated route path.

  • Tap on Start point to mirror the route

  • Tap on end point to make it start point


Weather forecast


If you're planning your flight beforehand, you can check weather forecast and sunrise/sunset time at your mission's location.

Weather forecast

Fly the mission


Connect your mobile device to the remote controller, place your drone to desired takeoff position and turn everything on. Open your mission if you made it beforehand.


Preflight settings and checks


Once your drone is connected to your device and detected by Copterus app, you will see its position on the map. Now you can adjust the flight route by tapping on scissors button and move slider circles to skip N first or/and N last waypoints.

Cut route path
DJI flight controllers are limited to 99 waypoints in a single mission. If you have a large area with more than 99 waypoints (turning points), the app will force the flight route to be cut to 99 waypoints. You can use route cut function to set the start point of your current flight and execute a large mission part by part.

Do not forget to check avoidance and safety settings of your aircraft, as well as overall systems state.

Tap any widget at the top bar to open drone's state and settings menu.

DJI drone system settings

When you are happy with the settings and ready to fly, tap FLY button.

The last step before take off is to set what your drone should do after mission has been completed and in case of RC signal failure during mission execution.


Mission settings

Here is an explanation of the options:


After mission is finished action

  • Go Home - after the last waypoint is reached, an aircraft will turn into RTH (Return To Home) mode and start its way to home position. If RTH altitude (from safety settings) is larger than current one, a drone will first reach that altitude and then move towards home position.

  • Hover - an aircraft will hover at the last waypoint waiting for you to control it manually.

  • Land - an aircraft will land at the last waypoint position

Lost RC signal action

  • Go Home - an aircraft will stop mission execution and engage RTH mode to return to home position.

  • Continue mission - if your aircraft flies beyond RC signal radius, or you turn off your RC controller, it will continue mission execution fully autonomously and perform finish action (described above) at the end.


Take off


Slide to confirm your drone to take off.


Danger! Be careful!

Shortly after you confirm to take off, motors will start spinning, and the drone will take off to execute the mission.


During mission execution


An aircraft executes a mission fully automatically, you have no need to control it except for safety reasons.

The flight speed is set so that drone's camera has time to take and save photos in a certain distance, however you can control it with your RC controller's right stick.

Move up to increase the speed or down to decrease it to 0 (stop) or to negative (fly back).

Controls available during mission execution:

  • Tap Go Home to stop mission and to engage RTH mode.

  • Tap Land to stop mission and land drone at where it is at the moment.

  • Tap Stop to completely stop the mission, hover and engage normal RC control.

  • Tap Pause to just pause the execution. Resume execution with Resume button which will appear instead.

If your drone runs out of battery during mission execution, it will automatically engage RTH (Return to Home) mode .



You are done flying!


After mission has been fully flown, find your imagery data on the drone's SD card and continue with processing.



Process aerial images


While surveying with drones, images of the ground are taken from multiple vantage points. Through processing these images, a photogrammetry software can then create orthomosaics and 3D models, from which it can measure accurate distance, as well as surfaces and volumes of physical objects.


Which photogrammetry software to choose?


Some photogrammetry software are desktop-based, thus requiring robust hardware. Other software is cloud-based, employing powerful servers instead of your local computer to process the data and you need fast internet access to upload all your photos to remote server.


Here is the list of recommended desktop and cloud-based photogrammetry software to process your survey data:


Desktop

Pix4D Mapper

Agisoft Metashape

Autodesk ReCap Pro

SimActive Correlator 3D


Cloud

WebODM Lightning

Pix4D Cloud

DroneDeploy

Maps Made Easy


We would tilt in favor of desktop based software. Cloud based software like DroneDeploy and MapsMadeEasy have their uses. But desktop based software is the go to solution if you wish to process voluminous data.

An inability to add in manual tie points is another disadvantage of cloud based software. Remember that having manual tie points increases the accuracy of your drone model. Another advantage of using desktop based software like Pix4D is the ability to make camera movements. The smoothness of camera movement depends on your computer power. This is not possible in cloud based tools.


Learn about advanced linear waypoint missions with Copterus app and DJI drones.