Processing image data

Follow these steps to import data from the drone:

• Step 1 - Select a flight: If the flight was monitored from the computer you are using to import images then the flight is saved within the localdatabase. Select the date that the flight took place. A list of flights (including number of images taken) from that date will appear in the combo box, select the one you wish to import. The flight’s trajectory will appear in the Map Area.

• Step 2 - Create a directory: Choose a directory name that uniquely identifies your flight (e.g. the date, the name of the area, etc.).
51Quick start guide

• Step 3 - Prepare data for import: To import the Drone Flight Log, connect the supplied USB cable to the eBee’s autopilot, marked with a icon. Connect the battery to the drone if it is not already connected. The status LED will become white and a new storage drive will appear on your computer. To import images, remove the SD card from the camera, insert it into the SD card reader of your computer and select ‘Import from SD-card reader’. Alternatively, transfer the images from the camera by lifting it out of its compartment just enough to connect a USB cable to it and turn the camera on. Copy all the images into a temporary folder on your computer. Select ‘Import from a specific folder’ and choose the temporary folder.
• Step 4 - Import flight logs: Confirm that the Drone and eMotion Flight Logs found by the Flight Data Manager are correct. You may select logs manually if they are not correctly detected.
• Step 5 - Import images: Confirm that the images corresponding to your flight were found and matched to the Drone Flight Log correctly.

52Processing image data

• Step 6 - Select outputs: Choose the output actions to execute and files to create:

– Only uncheck the first checkbox if you are sure you do not need to geo-tag your images. Geotagging images is necessary to create geoinfo, KML and Postflight Terra 3D files.

– Check the checkbox and choose a file format if you wish to export a geoinfo file. This file contains latitude, longitude, altitude (AMSL and WGS 84), heading, pitch and roll values for each image captured.

– Only uncheck the checkbox if you do not want to create a Postflight Terra 3D project.

– Only uncheck the checkbox if you do not want to create a KML file containing the 3D flight trajectory.
• Step 7: You may now disconnect the drone. Eject the SD-card drive and the drone drive before removing the SD-card and the USB cable, respectively. Disconnect the battery and USB cable from the drone. Insert the SD-card back into the camera, put it back properly into its compartment and ensure that it is turned off. You can now open the KML file in Google Earth TM or the project in Postflight Terra 3D for further processing. 

### 3.2 In-field image quality check Postflight Terra 3D software15, available as a free download with the eBee package, can be used to rapidly create a Quality Report directly in the field. The Quality Report that is automatically generated as well as the orthomosaic provide immediate feedback on the quality of the images gathered during your mission. You can open a project for processing in Postflight Terra 3D directly from the Flight Data Manager after importing your data by clicking the ‘Open project in Terra’ button. You will now see the main Postflight Terra 3D window. The position of your images will appear as red dots in the Map Area of Postflight Terra 3D. 15 powered by Pix4D; see section ‘ Installing eMotion, Postflight Terra 3D, and the ground modem drivers’ on page 20 for installation instructions
53Quick start guide

To create a Quality Report while in the field bring up the local processing panel by selecting ‘Local processing’ from the ‘Process’ menu or by clicking the icon in the Toolbar. Select only the ‘Initial project processing’ checkbox and the ‘Rapid’ button. If you wish to create a low-resolution orthomosaic while generating the report, check the ‘Orthomosaic and DSM generation’ checkbox. Click ‘Start’ to begin rapid processing. Postflight Terra 3D will now process the data and produce a report that includes the overall completeness and georeference quality of the images taken duringyour last mission. You may use this information to decide whether further imaging flights are required while you are still in the field. The quality report will be displayed in a new window (click the icon in the Toolbar if it does not appear).
54Processing image data



### 3.3 Creating advanced mapping products Beyond Quality Reports and low-resolution orthomosaics, Postflight Terra 3D can generate geo-reference d high-resolution 2D orthomosaics, 3D point cloud s, triangle model s and DSM s or export to common third-party photogrammetry software such as Bingo, Orima or Inpho. Ground Control Points (GCP) can be added to increase the geo-reference accuracy. Postflight Terra 3D also includes a mosaic and a rayCloud editor, giving you more control on the quality of your final mapping products, as well as measurement tools. The resulting orthomosaic and DSM may then be imported as custom background map and elevation data layers in eMotion16 . This data can be used for advanced flight planning in complex or uneven terrain. Note: You need to either enable tile set generation OR choose Generate Google Maps Tiles and KML from the Process menu before you can push the tileset into eMotion by choosing Send Map to eMotion from the Process menu. Alternatively, this data can be imported into eMotion; choose Import custom map from eMotion ’s File menu. Note: The best way to learn how to use the various features of Postflight Terra 3D is to look at the comprehensive online Knowledge Base within my.senseFly17

16 see section ‘Toolbar’ on page 90 for more information on importing layers into eMotion
55

## Part II



# Advanced functionalitiesAdvanced functionalities 

## 4 Understanding aerial mapping with the eBee Goal of this section: Aerial mapping using the eBee is designed to be simple and fully automatic, requiring very little input from the user. Understanding the basics of aerial navigation, however, can help youmap more complex terrain and yield higher quality results. This section explains the basics ofwaypoint-based navigation and the control strategies used by the drone for flight. 

### 4.1 Waypoints and their properties The eBee uses a flight plan consisting of a list of waypoints to navigate. A waypoint essentially consists of a circle about a given position and information that defines how the drone should behave when reaching them. The entire list of waypoints is stored in the drone autopilot and can be remotely edited using eMotion .

In eMotion every waypoint is defined by the following parameters:
• ID: Every mission waypoint has a unique ID, beginning at 1. The eBee can store up to 50 mission waypoints. Setup phase waypoints (Start and Home) do not have an ID.
58Understanding aerial mapping with the eBee

• Active: Indicates whether the waypoint is active or not. Deactivating awaypoint by clicking the checkbox beside its ID will remove it from the current flight plan. Setup phase waypoints (Start and Home) cannot be deactivated.
• Current: A status that indicates if the waypoint is currently being circled or navigated toward (indicated by > < around the waypoint’s ID). Only one waypoint is marked Current at a time.
• Change altitude: This parameter defines the way the drone transitions to the altitude of the current waypoint.

– During transit: The drone will fly in the direction of the current waypointwhile simultaneously changing altitude by climbing or descending in a linear fashion. If the required climb or descent rate is beyond physical limits, the drone will reach the destination and keepclimbing/descending around the destination waypoint. This is typically used to achieve the best efficiency when the altitude between waypoints is not constrained.

– Before transit: The drone will first climb or descend at its current position until it reaches the altitude of the currentwaypoint, and then fly in the direction of the waypoint at its altitude. This is typically used for 3D mapping.

– Keep highest: The drone will first determine whether its current altitude or the current waypoint’s altitude is highest. If the drone’s current altitude is highest, it will first fly towards the waypoint and then descent to the waypoint’s altitude in a circular fashion. If the current waypoint’s altitude is highest, the drone will begin by climbing at its current position until it reaches the waypoint’s altitude and then flytowards the waypoint. This is typically useful to avoid hitting the terrain in mountainous landscapes and, in particular, for the Home waypoint when the mission altitude is below the take-off location.
• Altitude: The altitude of the waypoint above the altitude reference. The waypoint is considered ‘reached’ only when the drone starts circling about it at the waypoint’s altitude.
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• Altitude reference: The reference point of the Altitude value. When set to m/ATO, the Altitude value is an Above Take-off (ATO) altitude. When set to m/AMSL, the Altitude value is a Above Mean Sea Level(AMSL). The altitudes of Setup phase waypoints (Start and Home) are always set to m/ATO.
• Turn direction: The direction with which the drone circles around the waypoint (clockwise or counter-clockwise).
• Radius: The distance at which the drone circles around the waypoint. Note: The eBee has a limited turning radius. Setting this parameter lower than 20 m may cause the drone to significantly deviate from its desired flight path.

• Auto-next: Indicates whether the drone should remain on the waypointupon reaching it (until a new command is received) or automatically continue to the next active waypoint.
• Action: The action (if any) to be performed upon reaching the waypoint. Supported actions include starting and stopping Continuous photo mode18
. Setup phase parameters (Start and Home) do not have associated Actions.
• Position (coordinates): The precise latitude and longitude of the centre of the waypoint. Waypoints are represented in the Map Area as circles with their actual radius and an arrow to indicate their direction. The flight path of the drone around and in between waypoints is drawn as a line of varying opacity; the path ahead of the drone’s current position is dark, becoming lighter the further it is from the current position in the flight plan. The path already traversed is a uniform light colour. If a waypoint’s Auto-next parameter is disabled, the path directly after it will be dashed, indicating that a command must be sent for the flight to continue. Clicking a waypoint in the Map Area will display its characteristics (waypoint ID for mission waypoints or name for setup waypoints, altitude, radius and action) 18 see section ‘Camera tab’ on page 118 60Understanding aerial mapping with the eBee

and will select it for modification. It will also activate the Mission Waypoints tab and highlight the selected waypoint.

You can modify the waypoint’s parameters directly in the Map Area using your mouse using the following actions:
• Position: Change the position by left-clicking on the waypoint and dragging it around on the map. By default the waypoint snaps to a position inline with the current flight lines before and after the waypoint. Hold down the ‘Alt’ button while dragging to disable the snapping feature.
• Turn direction: Hold down the ‘Shift’ button while left-clicking on a waypoint to toggle its turn direction. • Radius: Modify the radius by left-clicking on the waypoint’s perimeter and dragging it. • Altitude: Hold down the ‘Ctrl’ button while left-clicking on the waypoint and moving the mouse up or down to increase or decrease the altitude of the waypoint, respectively.
61Advanced functionalities

• Create new waypoint: Right-click anywhere in the Map Area that does not contain a symbol to bring up the context menu, then select ‘Add waypoint here’ to add a new waypoint. • Context menu: Right-click on a waypoint to bring up the context menu. You can then select the following options:

– Go to: Select while the drone is in flight to make this the current destination waypoint.

– Auto-next: Toggle the Auto-next parameter of the waypoint.

– Reverse turn direction: Toggle the Turn direction parameter of the waypoint.

– Change altitude: Set the transition behaviour of the drone when flying towards the selected waypoint.

– Remove waypoint: Remove the selected waypoint. Any modification will be sent directly to the drone to update its onboard waypointlist. If the message is not acknowledged by the drone (for example due to a temporary loss of communication link), the waypoint will move back to its previous position on the map to accurately reflect the current waypoint list status within the drone’s autopilot. Note: Modification of flight plan parameters can cause the drone to react in unexpected ways. In particular, the drone may have trouble following its flight path when the radius is set very low or if there is high wind. We highly encourage you to test your entire flight plan using the simulator to get familiar with the drone’s behaviours before going out into the field. 

### 4.2 Advanced polygonal mission area The mission area defines the area of interest where the eBee will take photos. Itappears as a grey rectangle when you select the ‘Mission planning’ tab and to calculate the flight plan of the drone. For many cases the rectangular-shaped mission
62Understanding aerial mapping with the eBee

area provides the simplest way to quickly create a flight plan. It can be modified as described in section ‘The mission phase of a flight’ on page 24 . For more complex areas eMotion has the option of using polygonal-shaped missions areas. Begin by converting a rectangular area into a polygonal area by setting the ‘Mission area’ type to ‘Polygonal’ in the ‘Mission planning’ tab or by rightclicking on the area and selecting ‘Convert to polygon’. A polygonal mission area is set slightly differently than a rectangular mission area:

• The edges of the rectangle now become vertices of the polygon. Left-click on a vertex to drag and reposition the vertex.
• Left-click and drag anywhere on the edge of the polygon to create a new vertex and reposition it.
• Right-click on vertex and select ‘Remove vertex’ to remove a vertex. Alternatively, hold down the ‘Ctrl’ button and left-click on a vertex to remove it.
• Left-click and drag on the dark-grey area within the polygon to reposition the entire polygon.
• Left-click and drag the circle on the corner of the light-grey rectangle surrounding the polygon to rotate the direction of the resulting flight lines. You may also set a polygonal mission area directly from a KML file containing a polygon, such as those created by Google Earth TM . Simply click on the icon in the ‘Mission planning’ tab, select ‘Load mission area from KML file’ and choose a KML file that contains the desired polygon. 

### 4.3 3D mission planning using elevation data eMotion has the ability to take into account elevation data to set the altitude of mission waypoints and the resulting flight lines of a mapping mission. This not only improves the resulting ground resolution but also increases mission safety
63Advanced functionalities

(particularly in uneven terrain) by keeping a more even height between the drone and the ground. You can display elevation data by clicking on the button in the Toolbar. eMotion ’s default Improved SRTM elevation data will be downloaded as tiles from senseFly’s servers and overlaid above the map as a colourmap19 . You can adjust the scale and opacity of the colourmap by using the associated buttons in the bottom-right corner of the Map Area.

Caution: eMotion ’s default Improved SRTM elevation data uses a 3 arc-second (approx. 90 m resolution) digital elevation model derived from the SRTM (Shuttle Radar Topography Mission) dataset version2.1 combined with other data sources (ASTER GDEM, SRTM30, cartographic data, etc.). This data covers nearly all emerged land except the territories below 56 ◦ S latitude and the territory of the Russian Federation above 60 ◦ N latitude. This data may contain inaccuracies of several meters, and does not contain data on obstacles such as buildings or trees. We highly recommend that you check your flight plan thoroughly in Google Earth TM and ensure sufficient clearance between the flight plan and the ground. SenseFly Ltd provides no guarantee regarding the accuracy of the elevation data and it is the operator’s sole responsibility to ensure a safe flight trajectory and altitude. Activate the 3D mission planning feature by selecting the ‘Use elevation data to set absolutewaypoint altitudes’ parameter in the ‘Mission Planning’ tab. Elevation data is used to adjust every mission waypoint altitude as follows: 1. The flight planner uses elevation data to find the maximal terrain elevation 19 eMotion must be connected to the internet. Once downloaded, elevation tiles are cached and can then be used off-line.
64Understanding aerial mapping with the eBee

under the current waypoint, the previous waypoint and the flight line that connects the two. 2. This maximum value is increased by the target altitude value, and the result is set as the altitude of the current waypoint. The altitude of every waypoint can always be manually adjusted in the Mission Waypoints tab. By default, the ‘Change altitude’ parameter for the first missionwaypoint is set to ‘Keep highest’. For all other mission waypoints the ‘Change altitude’ parameter is set to ‘Before transit’ so that the drone climbs or descends to the altitude of the next waypoint (and thus the next flight line) before transiting and taking pictures.It is important to understand that even if each flight line can have a different altitude, the altitude is constant along a given flight line. If the terrain altitude isuneven along a flight line, the resulting imagery will have varying ground resolution and overlap. When the mission planner computes the altitudes of flight linesit tries to ensure that the required amount of overlap is achieved, possibly leading to a lower ground resolution in some areas. During flight planning the range of ground resolution computed by the mission planner is displayed. For optimal results, it is best to set the orientation of the flight lines as parallel as possible to the terrain’s contour lines. One way to increase the resolution and accuracy of the elevation data is to fly a first mission at high altitude and then create a dataset using Postflight Terra 3D. You can then automatically import the data into eMotion by selecting ‘Send DSM to eMotion’ from the ‘Process’ menu within Postflight Terra 3D. The dataset can then be enabled using the menu in the Toolbar. eMotion will use this custom dataset (wherever it is available) to set waypoint altitudes instead of its default Improved SRTM elevation data. Note: It is recommended to visually compare imported elevation datasets with the default Improved SRTM elevation layer of eMotion in order to detect possible mismatches. This comparison should be done with a colourmap opacity value of 100%. More advanced controls of imported datasets are available in the ‘Elevation data’
65Advanced functionalities

panel of the Preferences pane of the menu. From this panel you can add, remove, activate/deactivate or reorder overlays. eMotion uses the top-most elevation data layer to calculate altitude for each waypoint and flight line, with eMotion ’s default Improved SRTM elevation dataset always considered the bottom layer.



### 4.4 Flight visualization in Google Earth TM eMotion includes an interface with Google Earth TM to help with flight plan verification and visualization, particularly in uneven terrain. Clicking on the button in the Toolbar will open Google Earth TM and zoom to the current position of thedrone. The current position of drone, its planned trajectory, the working area circle and all waypoints currently uploaded to the drone (including Take-Off, Start and Home) are displayed within Google Earth TM . Any changes to waypoints or flight parameters within eMotion are updated accordingly within Google Earth TM
. The interface with Google Earth TM is particularly useful to check the drone’s trajectory with respect to obstacles in the area20 . The flight plan is projected onto the
20 While checking flight plans in Google Earth TM is a good safety practice, senseFly Ltd provides no
66Understanding aerial mapping with the eBee

ground in a darker colour, giving you an idea of the distance between the flight path and the ground. If you connect to a simulated drone you can simulate the entire flight and follow the drone within Google Earth TM
. Note: To use this feature Google Earth TM has to be installed on the ground station PC, as described in section ‘ Installing eMotion, Postflight Terra 3D, and the ground modem drivers’ on page 20 . We recommend to use the latest version of the Google Earth TM software. Caution: A flight trajectory visualized in Google Earth TM represents the planned trajectory. The real flight trajectory can be different from the planned due to flight conditions such as strong wind. Caution: The terrain data within Google Earth TM , including hills and buildings, may contain significant errors. When planning flights over uneven terrain be sure to keep sufficient distance between the flight plan and the terrain.

guarantee regarding the accuracy and completeness of the Google Earth TM terrain model.
67Advanced functionalities



### 4.5 Autonomous controller and modes of flight

During a typical flight the autonomous controller on the eBee will switch between various modes depending on its flight plan and the commands that it receives from the Control Bar21 . The controller changes between modes during a typicalmission as shown in the figure above, and as described in more detail in the following list:
• After being switched on and running pre-flight checks the drone will enter Idle mode until it is ready to be launched. Shaking the drone back and forth 21 see section ‘Control Bar’ on page 95 for details on the Control Bar
68Understanding aerial mapping with the eBee

three times initiates the take-off procedure22 and changes to the Take-off mode.
• After take-off the drone climbs with level wings23, gaining altitude until it reaches the take-off transition altitude, by default 20 m 24 above the take-off location. At this point the drone heads for the Start waypoint and changes to Circle Start Waypoint mode.
• Once it reaches the Start waypoint, the drone circles the waypoint several times to estimate the strength of the wind. Once it calculates the estimated wind the drone either:

– heads towards the first mission waypoint, if ‘Start mission’ is selected in the ‘After take-off’ panel of the Setup Phase tab, and changes to Perform Mission mode.

– continues circling the Start waypoint until a command is received from the Control Bar (typically a ‘START MISSION’ command that is sent once a flight plan is finalized).
• While in Perform Mission mode the drone flies between all enabled mission waypoints, taking images of the ground below. Once it reaches the final mission waypoint the drone either:

– heads towards the Home waypoint, if ‘Land’ or ‘Go to Home waypoint’ is selected in the ‘After mission’ panel of the Setup Phase tab, and changes to Circle Home Waypoint mode.

– heads towards the Start waypoint, if ‘Go to Start waypoint’ is selected in the ‘After mission’ panel of the Setup Phase tab, and changes to Circle Start Waypoint mode.

– heads towards the first mission waypoint, if ‘Restart mission’ is selected in the ‘After mission’ panel of the Setup Phase tab, and remains in Perform Mission mode. 22 as described in section ‘Take-off ’ on page 43 23 or in a given direction when using the Directional take-off feature described in section ‘Setup Phase tab’ on page 102 24 see section ‘ Flight Parameters tab ’ on page 123 for details on changing this altitude
69Advanced functionalities

• Once it reaches the Home waypoint (if in Circle Home Waypoint mode) the drone will either:

– begin a Linear landing procedure(as described in section ‘ Linear landing ’ on page 72 ) and change to Linear Landing mode, if ‘Land’ is selected in the ‘After mission’ list and ‘Linear landing’ is selected in the Landing type list of the Setup Phase tab.

– begin a Circular landing procedure and change to Circular Landingmode, if ‘Land’ is selected in the ‘After mission’ list and ‘Circular landing’ is selected in the Landing type list of the Setup Phase tab.

– circles the Homewaypoint and remains in Circle HomeWaypoint mode until a command is sent.
• After completing a landing procedure and detecting that it has successfully landed, the drone changes to Idle mode.

• Turning on the remote control will cause the drone to enter either AssistedManual or Full Manual mode, depending on the setting in the Flight Parameters tab25 . Turning off the remote control will return the drone to its previous mode.
• Clicking the ‘HOLD POSITION’ button in the Control Bar at any time will cause the drone to start circling its current position and change to HoldPosition mode until it receives a new command from the Control Bar. Alternatively, right-clicking in the Map Area and selecting ‘Hold here’ will directthe drone towards the selected position and then circle around that position in Hold Position mode. This mode is also enabled automatically after certain In-flight warning or Critical failure conditions26
. • Clicking the ‘LAND NOW’ button in the Control Bar three times in quick succession will cause the drone to initiate a Circular landing procedure at its
25 see section ‘ Manual control of the eBee’ on page 127 for information on the various manual control modes 26 see section ‘Troubleshooting ’ on page 145 for a full list of In-flight warning and Critical failure conditions and the subsequent reactions of the drone
70Understanding aerial mapping with the eBee

current location with its motor disabled and change to Emergency Landing mode.

71Advanced functionalities



### 4.6 Linear landing A typical Linear landing follows these steps: 1. The eBee flies towards the Home waypoint (defined by the user within eMotion; default altitude is 75 m above the landing altitude). The altitude change behaviour between the current location and the Home waypoint depends on the ‘Altitude change’ parameter of the Home waypoint. By default, it isdefined as ‘Keep highest’, which means that the drone will fly at the highest altitude between its current altitude and the Home waypoint’s altitude, climbing in a spiral first if needed. 2. Once the Home waypoint is reached the drone circles the waypoint and descends to a fixed altitude of 75 m above the landing altitude. 3. The drone circles to estimate thewind speed and direction. An approach direction is then calculated as close to the upwind direction as possiblewithin the allowable approach sectors (defined by the user within eMotion ). 4. The drone flies downwind against the approach direction. After flying fora sufficient distance it turns around to align itself with the approach direction. 5. The drone glides down in the approach direction at a controlled speed and descent angle of approximately 20 ◦ , braking by spinning its propeller in reverse if necessary. 6. When the drone detects a height of around 20 m to the ground it begins to level out its descent. 7. When the drone detects a height of around 3 m to the ground it performs a final brake to reduce its speed and lifts its nose. 8. The drone then glides for the final few metres in a deep stall until it lands.

72Understanding aerial mapping with the eBee

73Advanced functionalities

The Linear landing process uses an optical-based sensor to detect the proximity of the ground. A number of conditions on the environment and the positions of the Home waypoint and approach sectors must be met in order for the ground sensor to function correctly and ensure the accuracy of the Linear landing:

• If the Linear landing location is not at the same altitude as the Take-off location you must adjust the Landing altitude parameter in the ‘Setup Phase’tab, as the drone uses this altitude to level out and slow down before landing (Steps 6-8). Enable the ‘Land at a different altitude than take-off’ checkbox and set the altitude as an absolute value in AMSL. Note: When ‘Land at a different altitude than take-off’ is enabled the Home waypoint’s altitude will be converted to AMSL instead of ATO (by default 75m above the landing location). Caution: Incorrectly setting the altitude of the Linear landing location will decrease the accuracy of the Linear landing and may result in damage to the eBee.

• A Linear landing can only be performed over flat terrain. Ensure that the ground is flat and at the same altitude as the Linear landing location for a distance of at least 100 m from the Linear landing location within every approach sector. It is also recommended to have flat terrain in the opposite direction of every approach sector in case a Linear landing is aborted in its final stages. Caution: Attempting a Linear landing on sloped terrain, the top of a roof or the edge of a cliff or any other terrain that is not flat will likely result in false detection of the height above the ground during the approach and may result in damage to the eBee. In particular, landing downhill may cause a large overshoot and should always be avoided.

74Understanding aerial mapping with the eBee

• Ensure that there are no obstacles within 60 m of the Linear landing location within all approach sectors and within a radius of 10 m around the Linear landing location. If there are some obstacles in the distance, ensure that the top of the obstacles is at no more than a 15 ◦ angle from the point 60 m from the Linear landing location, as indicated in the figure on page 73 . It is also recommended to not have any obstacles in the opposite directionof all approach sectors, in case the Linear landing is aborted before completion. Caution: It is not recommended to perform Linear landings between tall obstacles, as they may disturb the GPS signals your eBee needs to be able to navigate.

• In order to limit the ground speed when landing and to achieve the best landing accuracy, the eBee should only perform a Linear landing against the direction of the wind. Approach sectors should be as large as possible and in as many directions as possible to allow the drone to select the optimal approach direction based on its estimate of the wind. If all of the available approach sectors are in the direction of the wind an In-flight warning 27 will appear in eMotion when the drone calculates its trajectory (Step 3). Caution: If the drone performs a Linear landing in the direction of the wind during strong wind conditions or with certain In-flight warningsor Critical failures it may not be able to slow enough during its descent. It will likely overshoot the Home waypoint location and land at a high speed, potentially resulting in damage.

• The ground sensor must have sufficient light and texture to accurately detect the height above the ground. Ensure that the ground sensor lens isclear of dirt or other obstructions. Only attempt Linear landings in full daylight conditions. Ensure that there is high-contrast surfaces in all the ap-
27 see section ‘ In-flight warnings’ on page 151
75Advanced functionalities

proach sectors. Do not define approach sectors over low-texture surfaces such as large bodies of water, snow or sand.
• During a Linear landing the drone requires sufficient energy to slow downits descent and perform its final brake (Steps 5-7). If the Linear landing option is active and the battery descends below 20% an In-flight warning will appear28 in eMotion .To enable Linear landing select ‘Linear landing’ from the ‘Setup Phase’ tab. A single approach sector appears around the Home waypoint. Rotate and resize theapproach sector to define the directions around the Home waypoint that are completely clear of obstacles. You can add additional approach sectors from within the ‘Setup Phase’ tab. These approach sectors will be used by the drone to plan its landing path while taking into account the wind. Defining multiple possibleapproach sectors can increase the chance that the drone selects afavourable landing against the direction of the wind. Be sure that there are also no obstacles in a 10 m radius circle around the Home waypoint, as the Linear landing process may be effected by wind or positioning imprecision of the on-board GPS.

28 see section ‘ In-flight warnings’ on page 151 76Understanding aerial mapping with the eBee

Note: The eBee’s ground sensor can typically begin detecting groundproximity at a distance of 40 m. If the drone reaches an estimate altitude of 20 m/ATO (as estimated using the on-board GPS and pressure sensor) without a signal on its ground sensor it assumes thereis a malfunction with the ground sensor. This may be due to insufficient light or contrast in the environment, dirt on the sensor’s lens assembly or a Linear landing location at a different altitude than the Take-off Location. In this case the drone performs the braking and stall manoeuvre at an altitude of 20 m instead of 3 m. This increased time while stalled can greatly reduce the accuracy of the final landing position and damage to the drone.If the Linear landing process is aborted (by clicking on the ‘ABORT LANDING’ button in the Control Bar) before completion the drone will turn on its motor in fullthrust and gain altitude while continuing in a straight line in its approach direction. Once the altitude of 40 m/ATO is reached the drone will turn towards the Home waypoint and continue climbing until it reaches an altitude of 75 m/ATO. It then continues circling until it receives a further command. Caution: Do not abort a Linear landing if there are obstacles in theapproach direction behind the Home location, as the drone will continue flying in a straight line after an abort sequence while it gains altitude and may collide with those obstacles. Caution: It is not recommended to abort a Linear landing when the battery is low, as the drone may not have enough power to attempt a second landing.


### 4.7 Flying multiple drones at the same time Operating multiple drones at the same time enables the coverage of larger areas in a shorter amount of time. This can be useful when the mission time must bekept short, for example because of varying lighting conditions. To enable multi77Advanced functionalities

drone operation eMotion provides the following:

• When more than one drone is connected at a time, a dedicated interface called the Multi-drone panel is displayed to monitor each drone and switch between them.

• A number of settings are offered to keep relevant flight configurations(such as the Start and Homewaypoint) synchronised between all connected drones.

• Missions that require more than one flight can be automatically split and uploaded individually among all connected drones.

• A new Control Bar appears at the bottom of the Map Area. Commands sent using the buttons in this Control Bar, such as ‘START MISSION’ or ‘GO LAND,’ are sent to all the drones currently connected to your computer.

• Collision avoidance is provided by eMotion29 . This is done by automaticallychanging the altitude of the Start and Homewaypointsfor each drone in order to separate them. Also, the drones are automatically put on hold when there is a collision risk during the mission.When connecting to more than one drone at a time (real or simulated), a dedicated Multi-drone Panel is displayed next to the Sidebar. Each drone is displayed with its name, battery level and status and can be selected. The rest of the Sidebar and its various tabs are associated to the currently selected drone, as indicated by the colour of the frame. The multi-drone interface also displays the relative altitude of all drones with respect to the selected drone. Since this is a relative altitude, a value close to 0 m means that a drone is at the same altitude as the currently selected drone. Right-clicking on a drone’s tab in the Multi-drone Panel allows you to disconnect the drone or change its colour.

29 if the option is selected in the Multi-drones preference pane
78Understanding aerial mapping with the eBee

One advantage of flying multiple drone drones at once is to cover more area in less time. eMotion can automatically upload a multi-flight mission to all connected drones in a single click. To achieve this, follow this procedure: 1. Go to the Mission Planning tab and prepare the required mission area (this can be done with any of the connected drone selected). Make sure that the number of flights required matches the number of connected drones. If needed, the ‘Max flight time’ option can be lowered to force the mission planner to split the mission in several flights (see section ‘ Mission Planning tab’ on page 107). 2. Select ‘Upload to all’ from the drop-down list of the ‘Upload button’. Note: You can only split a mission between drones of the same model and that are using the same camera.
79Advanced functionalities

Clicking on the icon in the Multi-drone panel allows you to either connect a new drone or to bring up the Multi-drones preferences pane.

eMotion provides Multi-drone coordination options to synchronise various waypoints and parameters among connected drones:

• Take-off: Synchronising the take-off applies specifically to Directional takeoff heading and transition altitude.
• Start waypoint: When the Start waypoint is synchronised, eMotion will use the same location and altitudefor the Startwaypoint of each connecteddrone. Every modification to the Start waypoint of one drone is thus transferred to all other drones. To prevent collisions between drones, eMotion will automatically create a stack by incrementing the altitude of each drone that is currently circling the Start waypoints to ensure a 15 m separation. The base altitude of the Start waypoint, which is the altitude of the lowest drone in the stack, can be set in the Multi-drone Panel.
• Home waypoint and landing: Similarly to the Start waypoint, when the Home waypoint is synchronised eMotion will us the same Home waypoint
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for all connected drones. A stack will also be created to avoid collisions between multiple drones circling the Home waypoint. Caution: As eMotion defines the Start and Home waypoints in ATO. It is therefore critical for all drones to take off from the exact same location to achieve altitude separation and collision avoidance over these two waypoints.

• Flight parameters: This option will synchronise all the parameters in the ‘Flight parameters’ tab across all drones. This includes the Working area radius and ceiling, take-off transition altitude, Security action parameters, etc.
• Mission planning: This option will share the same Mission Area among all connected drones.
• Simulator: When checked, repositioning a simulated drone on the map will reposition all simulated drones at the same time. In addition to the altitude separation on the Start and Home waypoints described above, eMotion provides two traffic control mechanisms to help avoid collision between drones in flight:

• Proximity warning: When enabled, a visual and audible warning will be emitted if two drones are on a trajectory potentially leading to a collision in less than 7 seconds.
• Collision avoidance: When enabled, eMotion will constantly monitor the trajectory of the connected drones and automatically put one drone in atemporary hold pattern (similar to the HOLD POSITION function, see section ‘Control Bar’ on page 95 ) until it is safe to resume the flight. Priority isgiven to drones with the lowest battery level, engaged in a landing procedure or with an active error or warning.
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Caution: All collision avoidance mechanisms are implemented by eMotion on the ground computer. The drones’ autopilot do not communicate between themselves and do not have knowledge of each other’s positions. It is therefore critical to keep all drones connected to eMotion at all times and remain well inside communication range . Note: While eMotion strives to avoid all collisions, the operator is ultimately responsible to ensure flight safety. In particular, situations involving more that two drones in converging trajectories may notalways be handled automatically in a fully safe manner. It is recommended to use slightly different altitudes for each drone when flying more than two drones at a time to limit the risk of collision.In more advanced scenarios you may wish to share the position and even the control of a drone across a local area network. eMotion provides the following Network sharing options:
• Allow other computers to see my drones: All computers that are running eMotion and are connected to the same network will be able to display the position, status and other parameters of the drones connected to your computer. • Allow other computers to control my drones: All drones currently connected to your computer are not only displayed, but can be fully controlled by other computers running eMotion on the same network. • See all drones on my local network: Check this box to display the position and other parameters of drones connect to other computers on the same network. • Apply multi-drone coordination to local network: Check this box to synchronise all the selected parameters in the Multi-drone coordinationpreferences across all drones that are connected to the same network (provided that they have checked the ‘Allow other computers to control my drones’ option).
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• Share simulators on my local network: If this box is checked, all Network sharing options apply to both real and simulated drones connected to your computer. In unchecked, they only apply to real drones. 

### 4.8 Individual photo targets and oblique imagery In some cases it may be interesting to take oblique photographs of objects, for example to provide a nice image for documentation or to increase the quality of 3D models that contain vertical facades and surfaces. eMotion includes a tool for defining photo targets with a specific distance, heading and pitch angle. Thedrone can then orient itself and capture the image using a patent-pending pitchdown manoeuvre. Capturing an oblique image can be done easily by following these steps: 1. Add a new photo target by clicking on the button in the Camera tab. Use the cross-hairs to place the photo target on the location of interest in the Map Area. You may also right-click anywhere in the Map Area and select ‘Add photo target here’ from the contextual menu. The photo target will appear as a circle in the Map Area with an estimated image footprint, a manoeuvre zone and a status panel with estimated altitudes before and after the image is taken.

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2. Select the desired heading and pitch angles of the image by rotating theimage footprint and moving the photo target arrow, respectively. The estimated image footprint can help you choose the required angles. You can also set the angles manually in the ‘Photo targets’ section of the Camera tab. 3. Define the desired ground resolution at the photo target within the Camera tab. You can also adjust the ground resolution by resizing the photo footprint in the Map Area. Caution: Be sure to define a ground resolution that is high enough to allow the drone to recover from its pitch manoeuvre by paying closeattention to the ‘Minimum altitude after photo’ parameter. We recommend that you do not define parameters that result in an ‘Minimum altitude after photo’ of less than 30 m, in particular when selecting a high pitch angle. 4. Define the altitude of the photo target, if it is not the same as the take-off altitude. You may use elevation data to define this altitude by enabling the ‘Use elevation data to set absolute photo target altitudes’ checkbox. Repeat the above steps to define multiple photo targets. After launching yourdrone, click on the ‘Begin sequence’ button in the Camera tab at any time to begin taking the images. The eBee will fly to the location of the first photo location,measure the wind above the location, and perform a dive (pitching down) manoeuvre to take the oblique photo. It will perform this for all photo targets until it has completed the entire sequence. Taking a series of oblique images of the same photo target at regular heading and pitch intervals allows you to create a higher quality 3D model of a photo target. You can use the ‘New photo target increment’ to define a desired increment angle. Clicking on the button will then add a new photo target at the same location as the previous target but with an incremented pitch and heading value.A more detailed description of all the available options for taking images of individual photo targets can be found in section ‘Camera tab’ on page 118 . 84Understanding aerial mapping with the eBee



### 4.9 Emergency Manoeuvres Despite careful planning, unexpected situations might place people, property, animals or your drone in danger, for example:
• Unexpected intrusions into your eBee’s airspace by low-flying aircraft or other UAVs. • Flight planning errors. • Unexpected intrusions into the landing zone. • Birds approaching or attacking your drone. • Unexpected changes in wind conditions. As a precautionary measure to be used only when absolutely necessary, the eBee has been programmed with a series of emergency manoeuvres:
• Land now The drone immediately initiates a circular landing around a 30 m radius waypoint at its current location. • Abort landing The drone aborts its landing, climbs up to a safe altitude and circles waiting for a command. See section ‘ Linear landing ’ on page 72 for more details. • RollThe drone performs a roll along a linear flight path, then resumes its mission. • Fast climbThe drone suddenly climbs with full thrust approximately 40 m then gradually descends (at approximately -4 m/s) back to its initial altitude. • Fast descent The drone enters a spinning dive. It then pulls out if the dive, resulting in between 15 and 30 m of lost altitude, and climbs gradually back up to its initial altitude.
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Activating Emergency Manoeuvres The land now and abort landing buttons are always available on the control bar. To activate the roll, fast climb and descent features: 1. Choose Preferences from the File menu. 2. Choose the User interface pane.

3. In the Advanced buttons panel, check the manoeuvres you want to activate and click OK. Buttons that trigger the manoeuvres are added to the Control Bar:

Note: To trigger the ’land now’ manoeuvre, click the land now button 3 times in quick succession (within half a second). A landing can only be aborted in the absence of critical failure.

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When to use the Emergency Manoeuvres You might need to use an emergency manoeuvre in these situations: Presence of birds Birds approach your drone out of curiosity, or they consider it a threat and attack it.

• To try and escape an isolated incident, consider using the fast climb or descent manoeuvres.
• To try and startle the birds and dissuade themfrom approaching your drone, consider using the roll manoeuvre.
• In the even of a sustained attack, or a situation that may put the birds at risk, land your drone. Note: Consult with your local authority or wildlife conservation association before flying in sensitive areas. Avoid flying near known nesting sites, especially when young are present in spring or early summer. Rather than disturb the birds, consider flying at a different time of year or adapting your flight plan to minimise your impact on wildlife. Flight planning oversightsYou have moved the home waypoint on uneven terrain, but you have not corrected the landing altitude to compensate for the change in ground level under the new home waypoint. You think there is a risk of a hard landing for some other reason. Unexpected wind or a flight planning oversight means that your drone will land on water or in some other unsuitable place. Consider aborting the landing, correcting the error, and landing again.
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Unexpected intrusions into airspace Your drone is about to collide with another aircraft or UAV. Consider a fast climb or descent. Unexpected intrusions into landing zoneA person or vehicle moves into your landing zone during landing approach. Consider aborting the landing. Caution: You cannot trigger an emergency manoeuvre if it will:
• cause your drone to leave the working area. • make your drone fly below 30 m and cause a ground proximity warning. • interrupt an emergency landing that was caused by a critical failure.
Caution: To avoid a collision, do not carry out a fast climb or fast descent if this would risk flying close to trees or other obstacles. Caution: Some of these manoeuvres will cause a loss in altitude. Toavoid crashing your drone, do not carry out several emergency manoeuvres in quick succession. Allow your drone to stabilise its flight and altitude after each manoeuvre. Caution: While your drone is carrying out an emergency manoeuvre it cannot capture high-quality images and some images may be missing at the end of the mission. In addition, these manoeuvres useup battery power, shortening the available flight time. If, after activating a manoeuvre 3 times, the issue has not be resolved, considerlanding and waiting (for example, until birds have left the area) before restarting or resuming your mission.

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## 5 eMotion in-depth guide
Goal of this section: eMotion is a powerful tool designed specificallyto work with your senseFly mini-drones. This section includes a comprehensive guide to all thefunctionalities in eMotion to help you plan, simulate and monitor your next mapping flight.

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The main eMotion interface is composed of a Map Area, a Toolbar and a Sidebar30
. The Map Area displays the current location of the eBee, a Status Panel with important information on the drone’s current status, and a Control Bar used to send commands to the drone (section ‘Control Bar’ on page 95 ). The Toolbar above the Map Area includes the File menu, controls for selecting the source of map data, the display of picture footprints and various other controls (section ‘Toolbar’ ). The Sidebar is separated into six individual tabs that are used during different phases of planning and monitoring a flight. The Sidebar tabs can be hidden at any time by clicking on the left-hand edge of the Sidebar. Each tab is describedin detail in the following chapter. The Sidebar also contains controls for the Simulator (section ‘Simulator’ on page 93 ) 

### 5.1 Toolbar

You can access the File menu by clicking on the button in the Toolbar. From thismenu you can connect to or disconnect from a drone, access the Flight Data Manager, change eMotion preferences or import custom maps. Clicking the icon will launch Google Earth TM and display the current flight trajectories of drones connected to eMotion, as described in detail in section ‘ Flight visualization in Google Earth TM ’ on page 66 . 30 for an overview of the eMotion interface see section ‘The eMotion interface’ on page 21 90eMotion in-depth guide

You can select the background map source from the drop-down list in the Toolbar, and adjust its zoom level using the and buttons. eMotion can use many sources of commercially available and custom mapping information. Tiles from map sources with the icon are downloaded by eMotion from the Internet as required and locally cached on the hard drive. Due to regulatory restrictions, map sources with the icon cannot be saved locally and are not recommended for use in the field. If you anticipate the use of eMotion in conditions where connecting to Internet is impossible, you can preload the map data by selecting ‘Download maps...’ from the File menu. Follow the instructions in the dialog box to select the zone of interest, map tile source and start downloading. eMotion can also import and display custom layers which may include KML files, custom map tiles and elevation data. To import a KML file, select ‘Import KML...’ from the File menu and select your KML file. The resulting layer will now be available in the Toolbar by clicking on the icon, and can be clicked to display or hide it. eMotion can display lines, polygons, paths and points saved in KML format. Note: KML files, including associated icons or images included within them, are not copied to the eMotion directory and will no longer appear in eMotion if the original KML files are deleted. Custom map tiles can also be added as a layer in eMotion . These tile sets must be TMS-compatible sets of files. Select ‘Import custom map...’ from the File menu and select the folder that contains the tile set. The tile set will then appear in the list of layers in the Toolbar, accessible by clicking the button. Note: If you use Postflight Terra 3D (see section ‘ Processing image data ’ on page 50), you can generate TMS-compatible, eMotion
compatible tile sets for each project. In this way, you can create your own map background using the eBee. Generate the tile set by selecting ‘Generate Google Maps tiles and KML’ from the ‘Process’ menu within Postflight Terra 3D. Whenever the eBee takes a picture, eMotion records the location and orientation of the drone and computes the approximate span of the photo on the ground (or
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‘footprint’). All the footprints taken by a drone are added to a shaded polygon outlined with the drone’s colour and displayed in the Map Area. This polygon represents an estimate of the area that has been photographed by the drone.

The footprints can be shown or hidden using the button. When hidden, thefootprints are kept in memory and new photos continue to be recorded, but nothing is displayed in the Map Area. Footprints for all drones remain in the memory of eMotion, even when a drone is disconnected or eMotion is shut down. Clicking on the button removes all footprint polygons from the Map Area the memory of eMotion . New picture footprints will be created for subsequent pictures that are taken. Note: Clearing or hiding the footprints has no influence on what is logged by eMotion and on-board the drone during the flight, such as the information required to geotag the images after the flight. Note: The footprints displayed on the map are only an approximateestimation of the actual ground coverage of the corresponding image. Cross-wind may introduce errors in the orientation of the displayed footprint compared to the actual coverage, whereas inaccurate elevation data may result inaccurate footprint size.The Toolbar also contains buttons for centering the Map Area on the current position of the drone ( button), on a searchable location or coordinate ( button) or to continually follow the position of the drone while it is in flight ( button). Finally you can view eMotion in full-screen mode by clicking the button.
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### 5.2 Simulator Familiarising yourself with your eBee and its features will allow you to more efficiently plan and execute mapping flights, saving you time and improve your imaging results. The Simulator in eMotion is designed to help you test the variousfeatures of the drone and to better prepare a mapping mission before performing it in the field. Several simulated drones can be connected at the same time, allowing you to test multi-drone functionalities.

The Simulator bar appears at the bottom of the Sidebar of eMotion when you connect to a simulated drone. The simulated drone will go through the same preflight checks as a real eBee, after which it will update the Home to its current position (typically the last position that was used within the simulator) and the Start waypoint to 80 m West of the Home waypoint. The various buttons available in the Simulator bar are described in table 1 on the following page. Feel free to modify the wind speed, waypoint positions and other parameters in the Toolbar and the various tabs of the Sidebar in eMotion to see their effect on the eBee while it is in flight. Also be sure to explore the effects of the various buttons in the Control Bar on the behaviour of your drone. Don’t be afraid to push the boundaries! Aborting a flight or causing an emergency landing in the simulator will better prepare you for unexpected circumstances while in the field.

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Table 1: Simulator bar buttons

Button Description Pause Clicking the pause button will pause the simulation

and thus stop the drone while in flight. This can beuseful when you wish to change parameters or waypoints while the drone is already in flight. Note: this is a simulated action that is not possible with the real eBee. Instead of pausing while in flight we recommend that you use the ‘HOLD POSITION’ function to better simulate real flight conditions. Play Clicking the play button returns the simulation to actual speed from the pause or fast-forward conditions. Fast forward Clicking this button increases the speed of the simulation to 4x actual speed. This allows you to shorten the time required to simulate a complete mission. Re-position take-off location Clicking this button and then clicking on a location

in the Map Area simulates the action of connecting the battery to the drone in a new location. The drone is returned to the ground at the new locationand runs through its pre-flight checks before entering Idle mode. Initiate take-off Clicking this button simulates a take-off procedure,

including the motor power-up sequence and the hand launch 31
.

31 see section ‘Take-off

’ on page 43 for a description of the take-off procedure
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Instant recharge of battery Clicking this button will instantly recharge the battery of the drone. Note: This is a simulated action that is not possible with the real eBee while it is in flight. Wind speed and direction These fields are used to input a simulated wind speed

and direction. A random wind speed and direction is set when eMotion connects to a simulated drone.



### 5.3 Control Bar

The Control Bar includes buttons for sending commands to the drone and for acknowledging warnings while it is in flight. Certain buttons can only be used during specific flight modes32
. The Command buttons allows the operator to directly control the drone while it is in flight. The various buttons are described in table 2 on the next page.

32 see section ‘Autonomous controller and modes of flight’ on page 68 for more information on flight modes
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Table 2: Control Bar Buttons

Button Available Action WARNING33 Active

warning For yellow In-flight warnings, button text

changes to ‘ACK WARNING’ and clicking will acknowledge the current warning. For redCritical failures, button text changes to ‘CRITICAL FAILURE’ and cannot be clicked. START MISSION No active

Security action Fly towards the first active waypoint in the

waypoint list and start the mission from the beginning. RESUME MISSION Not in Perform

Mission mode Return to the last position reached during

the mission and continue the flight plan. GO TO START WPT No active

Security action Fly towards the Start waypoint, circle and

wait for next command. GO TO HOME WPT Anytime Fly towards the Home waypoint, circle and wait for next command. GO LAND Anytime Fly towards the Home waypoint and initiate landing procedure. HOLD POSITION No active

Security action Create a virtual waypoint at the current location and altitude, circle around this point and wait for next command.

33 see section ‘Troubleshooting ’ on page 145 for a full description of In-flight warnings and Critical failures that may occur
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LAND NOW Click 3x Anytime Initiate a Circular landing around a 30 m radius waypoint at the current location. Must be clicked 3 times in quick succession to be engaged. ABORT LANDING During Circular Landing, Linear Landing, or Emergency Landing mode (if no active Critical failure) Circular or Linear landing: abort current

landing procedure, return to the altitude ofthe Home waypoint, circle the Home waypoint and wait for next command. Emergency landing: (only available if there is no active Critical failure) abort current landing procedure, return to the location where the Emergency landing was triggered, circle and wait for next command.

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### 5.4 Flight Monitoring tab

The Flight Monitoring tab can be used to monitor the eBee during a mapping mission and is the default tab that is displayed when you click anywhere on the map area that does not have a symbol. The tab is split into the following sections:

• Drone Status: The status of the plane keeps you informed on what the drone is currently doing. This can include mission actions such as ‘Taking photo’ or ‘Going to waypoint’ as well as warning or failure messages such
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as ‘Out of working area’ or ‘High wind’34
. Note: The most important status and warning messages are reproduced in the Status Panel in the Map Area, and thus remain visible even when the Sidebar is hidden.

• Autonomy: The battery level displays the current charge and voltage of the battery. As the battery’s charge level decreases, the voltage decreasesas well. A fully charged battery has a voltage of 12.6 V and is fully discharged when it reaches about 9 V35
. This section also displays the total time in flight, the straight-line distance to the Home waypoint, the estimated time required to return to the Home waypoint (based on estimated wind strength) and the quality of the radio data link between the ground modem and the drone. The strength and direction of the wind estimated by the drone is displayed with an arrow. Caution: Lithium polymer batteries are chemical devices whose performance depends on a number of parameters, including temperature, lifetime, number of cycles, mechanical integrity, etc. Estimatingthe remaining capacity of a battery can thus be tricky and the displayed value may occasionally be inaccurate. It is the operator’s responsibility to monitor battery voltage and flight time in addition tothe battery level to make sure that endurance is sufficient to complete the mission.

• Flight data: This section includes additional information that may be useful during the flight, including ground speed and height, altitude AboveMean Sea Level (AMSL) and the absolute position detected by the GPS onboard the eBee. 34 see section ‘Troubleshooting ’ on page 145 35 see section ‘ Proper battery care’ on page 142 99Advanced functionalities

Note: The ground sensor height indicates the height above theground detected by the ground sensor. The sensor can typically detect distances below 60 m, depending on available light and surface contrast.

• Instruments: This display mimics the classical primary flight display used in manned aircraft. The column on the left displays the current air speed of the eBee as well as the desired air speed, in metres per second. The column on the right displays the drone’s current altitude over take-off location, as well as the desired altitude over the take-off location, in metres. The bar at the top displays the current heading of the drone36 . North is indicated as 0 ◦ , East as 90 ◦ , South as 180 ◦ and West as 270 ◦ . • Identification: This displays the serial number of your eBee and the number of the Drone Flight log for the current flight. This number can be used as a reference when importing flight data after a flight37
. • Payload information: This section displays the payload currently selected and the number of photos that has been taken since take-off 38
. 36 this feature is only accurate when in flight 37 see section ‘ Importing images and flight data ’ on page 50 38 see section ‘Camera tab’ on page 118 for instructions on changing the payload type
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