The present invention provides methods and systems of tracking a target with an imaging device onboard an unmanned aerial vehicle. The method may comprise identifying one or more targets in a first image captured by the imaging device, receiving a user selection of a target to be tracked from the one or more targets in the one or more images, generating target information for the target to be tracked based on the user selection of the target, detecting a deviation of a detected position and/or a detected size of the target in a second image captured by the imaging device from the selected position and/or the selected size of the target in the first image and adjusting at least one of the UAV and the carrier, to reduce the determined deviation to maintain the target substantially within the field of view of the image device, based on the deviation.