Abstract: The present invention relates to a method for calibrating an altitude sensing stereo vision device (122) of an unmanned aerial vehicle (100), wherein the method includes: arranging the unmanned aerial vehicle to take off from ground (G) and ascend; deriving at least one first altitude value (10a-15a) from the stereo vision device and obtaining at least one corresponding second altitude value (10b-15b) from another device (123) of the unmanned aerial vehicle during the ascent (1) of the unmanned aerial vehicle; recording the derived at least one first altitude value and the obtained at least one corresponding second altitude value as calibration data; deriving an additional first altitude value from the stereo vision device while the unmanned aerial vehicle flies a route; and adjusting the derived additional first altitude value based on the recorded calibration data.

Abstract: The present invention relates to a computer-implemented method for improving the interpretation of the surroundings of a vehicle (100), wherein the method comprises: receiving a source image (14) of a surrounding environment (118) of the vehicle, which source image is captured by a sensor unit (12a) of the vehicle; receiving or computing a depth data image (20) comprising depth data based on the source image and at least one more source image; detecting a repetitive pattern (30) in the received source image; and based on the detection of the repetitive pattern, determining that an area (32) of the depth data image, which area (32) corresponds to an area (34) of the detected repetitive pattern in the received source image, contains unreliable depth data.

Abstract: A method for improving the interpretation of the surroundings of a UAV, and to a UAV system is presented herein. The method comprises the steps of acquiring an image comprising depth data, and determining a boundary between a first image portion and a second image portion. The second image portion surrounds the first image portion, and the boundary is defined by an interface between first periphery sub-portions and second periphery sub-portions. A difference in depth data between adjacent first periphery sub-portions and second periphery sub-portions is above a first predetermined threshold and/or second periphery sub-portions comprises undefined depth data. The method further comprises determining the area of the first image portion, and if the area of the first image portion is below a second predetermined threshold, determining that the first image portion contains incorrect depth data and deleting and/or adjusting the incorrect depth data contained by the first image portion.