Operations

Flight Modes

  • Loiter - Loiter Mode automatically attempts to maintain the current location, heading and altitude. The user will manually control these aspects of flight with the joysticks, but when the sticks are released, the vehicle will slow to a stop and hold position. The drone should ALWAYS be flown in loiter mode if flying manually. This is mapped to the A button on Wispr controllers.

    • Wispr Ground Control automatically sets the flight mode to loiter when booted.

  • Altitude Hold - When Altitude Hold mode is selected, the throttle automatically controls the current altitude. The drone will remain steady at its current altitude using the barometer, but will drift in potentially any direction, as it is not reading from the GPS in this mode. The joysticks on the controller should be used to maintain position to the best of your ability. Altitude hold should ONLY be used in an emergency situation such as a failed GPS, or if the drone is losing stability in flight. This is mapped to the B button on Wispr controllers.

  • Land - Automatically attempts to descend the drone directly below its current position, land, and disarm. To prevent crashes, it is strongly urged that the user does not adjust position of the drone when attempting to land. This is mapped to the C button on Wispr controllers.

  • Return To Launch (RTL) - The drone will ascend to the designated altitude before orienting itself toward home, and when positioned above the launch location will lower itself to the ground before disarming upon touchdown. This is mapped to the D button on Wispr controllers.

  • Auto Flight Mode - This mode is exactly what it sounds like- automatic. This mode comes into play when conducting missions, and directs the drone to carry out the instructions written in the mission that has been planned. The drone will fully complete the sequence and return to launch unless interrupted.

  • Guided Flight Mode - Guided flight mode is a lesser used mode that is only applicable for a few functions of flight. This mode functions similarly to Auto flight mode, but applies to smaller sequences that might be performed one or more times in a flight, as well as before conducting a mission. This mode is active when performing a LiDAR calibration, a bridge scan, or a go-to sequence.

What mode should be used to land the drone?

  • Land mode should be used. The land command (the C button on the controller packaged with Wispr drones) should be issued 6-15 ft from the ground. The user should always use the land command to land the drone, unless it is not an option due to circumstances such as a safety issue or a crash hazard.

    • If a hazard becomes present during landing that makes land mode unsuitable, the drone may be landed using the joysticks and disarmed by holding the left joystick down and to the left. This is for emergency cases only. Manual landing is reserved for emergency situations such as to avoid injury or destruction of property.

  • Alternatively, the user can always issue an RTL (Return To Launch) command.

    • Note that when an RTL takes place, the drone may possibly land a few feet away from the initial takeoff position. As such, users may need to reposition to land in a level spot or avoid an object on the ground. We never recommend adjusting the position of the drone when it is in an RTL or Land sequence. If you feel you need to reposition for landing, shift to loiter beforehand, and land using land mode when you are happy with your positioning.

If my drone is not flying smoothly, what should I do?

  • Check that the payload, propellers, screws in the drone, screws holding propellers and landing gear are all secure.

  • Verify that no errors are being triggered in Wispr Ground Control.

  • If the compass (GPS) has been bumped or has been damaged in some way, this can also cause the drone to not fly smoothly. In a worst case scenario, a crash could occur if the GPS is not reading correctly.

  • It may be necessary to recalibrate the GPS if the flight characteristics observed appear quite unstable.

Note: if you are flying on a windy day, you will observe some movements that are a result of the drone trying to counteract the wind it is in the path of. The more you fly, the better you will be able to discern if the flight behavior you’re seeing is abnormal, or a result of the drone holding its position.

Obstacle Avoidance

Obstacle Avoidance is a feature that can be used when a Proximity Sensor is installed in a drone, allowing the drone to detect nearby objects it might hit during flight, and attempt to prevent collision.

Usage:

The obstacle avoidance sensors have two settings in WisprGroundControl that can be adjusted based on the users needs.

  • Proximity Sensor Distance (m):

    • This adjusts how far way (in meters) that the detected object must be from the proximity sensor for the obstacle avoidance to activate.

  • Avoidance Activation Height:

    • This adjusts how high (in meters) from the ground that the drone must be for the obstacle avoidance to activate. For example, at the default of 3m, no objects below 9ft should trigger the avoidance behavior. This is useful if you need to take off in a congested area.

Behavioral Notes:

  • When the OA triggers, the drone will brake and hold position. Sometimes the braking action can cause the drone to float back ~1-3ft as it settles into an idle.

    • When the drone has higher speed, the drone may bank to the left or right to disperse the momentum it’s accumulated.

  • The OA will trigger when detecting the ground if the drone is low enough, as the tilt from flying forward causes the sensor to angle downward somewhat.

    • If resuming the mission from a higher altitude that the leg was being flown at, the drone will descend as it progresses toward its waypoint simultaneously. Returning to target alt before resuming is recommended.

  • If the OA detects an object, sometimes the drone will prevent horizontal movement if the drone is particularly close to it, This may require the user to rotate the drone or increase Alt so that the sensors can’t see the obstacle.

  • If the OA detects an object and the user gives forward throttle, the drone will attempt to execute the manual command but almost immediately stop itself. If the user forces it enough there have been observations of the drone either:

    • Refusing to do more than inch forward when given input, but also refusing to move backward (believe this is related to the lateral movement restriction).

    • Lead to a situation where the sensor seems to give up trying to avoid/registers the surface as not an obstacle. This has only been observed when stress testing the avoidances, shouldn’t be the case in normal context.

  • If taking off while in detection radius of an obstacle, the avoidance will not try to avoid that obstacle until exiting detection radius and then detecting it again.

Ground Control Points


What is a Ground Control Point (GCP)?

  • Ground control points are points on the ground with known coordinates.

What is a Survey Check Point (SCP)?

  • Survey checkpoints are points with known coordinates that are used to validate the accuracy of the survey.

What spacing is recommended for ground control points for your system?

  • Under 1000ft spacing is best practice when setting Ground Control Points (GCP).

How many ground control points are needed?

  • In a 500 Square Kilometer area the best practice is to have at least 20 Ground Control Points on non-vegetated surfaces easy to see from the sky and 5 ground control points on vegetated surfaces visible from the sky per ASPRS 2014, p.A19.

What is the best use of targets for Ground Control Points (GCP)?

  • 1.5ft x 1.5ft square target is best with a visible center point.

Where do ground control points need to be placed?

  • Place ground control points within 100 ft of the edge of the survey area and throughout the center of the survey area as well.

RTK

What is RTK and when should I use it?

  • RTK is a navigation system that offers very precise position accuracy of your drone. The RTK system is always in use on the drone’s GPS, but can be enhanced with a better signal by using a ground station that communicates with satellites and provides real-time location during the flight.

  • RTK can be used when you are in an area where your GPS is picking up a low amount of satellites or you have no GPS at all.

  • RTK can be used with mapping and LiDAR, as it will ensure your drone remains steady horizontally and vertically. This is key in getting accurate results and enhanced positional data down to a centimeter resolution while mapping.

  • RTK is also used with the Camera Controller. The Camera Controller supports writing of GPS/RTK and gimbal angles from your flight controller directly to the EXIF of photos in the camera SD card. RTK will ensure accuracy when pictures are being taken and data is later processed.

How do I set up my RTK system to work with a Wispr drone?

  • To connect your RTK system to your drone, you will need to first make sure you have the Portable Wi-Fi hotspot enabled (on the smart controller) which you can find in the Wireless & Networks section.

    • Turn the option on using the toggle switch in settings. To do this you can swipe down from the top of the screen and select the icon on the far right to activate tethering.

Tap the Icon in the Top Right
The Option Outlined in Red Will Appear
  • Set up your Wi-Fi hotspot with a network name and password then select save. Now you can connect to your tethered Wi-Fi hotspot under your Wi-Fi list.

  • Open the General Settings tab in Wispr Ground Control and scroll to the bottom to the NTRIP section.

  • Enable the NTRIP server by ticking the box and enter your NTRIP information. Once done, reboot the drone and Wispr Ground Control.

    • You are connected to the RTK base if when clicking the satellite icon in the fly bar you see “3D RTK GPS Lock (Fixed)” informing you that you are now connected to your RTK Base.

For a walkthrough video, visit this link: RTK with WISPR Ground Control Quick Start Video

How do I connect my Here+ RTK to the Wispr Drone through Wispr Ground Control?

How much power is supplied from the front XT60 power output port?

  • 24 Volts. Although it is an unregulated 6S voltage, which is 21-26.1 volts.

How often should I get my Drone tuned up?


Troubleshooting

If one of the cooling fans under the bottom plate stops spinning, is it still ok to fly the drone?

  • No! If a fan stops working, please submit a ticket here: Report a Problem to get the fan replaced. The drone needs all 4 fans to help cool the inside of the drone to prevent overheating. DO NOT fly if you are aware a fan is not working. This could lead to overheating and the drone malfunctioning.

What should be done if “Open Drone ID: waiting on controller location” will not clear for takeoff?

Make sure your location services are enabled, which can be done by swiping down from the top of the screen and tapping the center icon, shown below:

More information for Remote ID can be found at this link.