Since 2007, I have spent some time looking for relatively tall trees that provide a good view out over the surrounding trees. The application is to use such trees to keep watch for a rare bird flying over the distant treetops. One of the approaches was to climb one tree and use it to spot other trees that might be useful as observation platforms. We used a precise compass and (when possible) a laser range finder to estimate the coordinates of trees. This approach is effective for trees that aren't too far off, but it can be difficult to locate distant trees, which are often difficult to see and/or recognize from the ground.
I recently experimented with a simple approach for locating trees with a P3 Pro. I set up missions in Litchi with the coordinates of waypoints chosen precisely. First do a north-south track with the camera aimed due west. Then do an east-west track with the camera aimed due north. In order to account for the fact that the drone doesn't instantaneously get up to cruising speed, I obtained images from reference points a short distance inside the end points and used those points as the actual end points. With this approach, it is possible to get a pretty good estimate of the coordinates of an object based on the timing of when it crosses the center of the picture. It allows one to obtain information on the locations of several trees with just two flights (which could be combined into one flight).
I recently experimented with a simple approach for locating trees with a P3 Pro. I set up missions in Litchi with the coordinates of waypoints chosen precisely. First do a north-south track with the camera aimed due west. Then do an east-west track with the camera aimed due north. In order to account for the fact that the drone doesn't instantaneously get up to cruising speed, I obtained images from reference points a short distance inside the end points and used those points as the actual end points. With this approach, it is possible to get a pretty good estimate of the coordinates of an object based on the timing of when it crosses the center of the picture. It allows one to obtain information on the locations of several trees with just two flights (which could be combined into one flight).
