Unmanned aerial vehicles (UAV) are currently a very rapidly developing type of aviation. The problem of support during the take-off with the use of, i.e. take-off launchers arose along with their development, especially for UAVs with weights and dimensions preventing manual take-off. One of the major issues associated with UAV take-off launchers is for its UAV accelerating element to obtain its initial speed. The article presents three methods of determining launcher take-off speeds for unmanned aerial vehicles, i.e. the concentrated very oblique projection method, the high-speed camera methods, and the acceleration recorder method. The take-off launcher carriage speed in the oblique projection method is determined from a formula. This method involves “ejections” of concentrated masses from the UAV mass range and measuring the component values resulting from the used formula, which contains the range of the oblique projection, the elevation of the projection and its angle. The method using the high-speed camera involves recording the course of ejections of the concentrated mass from the launcher. The average take-off speed is determined on the basis of a take-off run length (section of the launcher race, where the unit accelerates) and defining the start and end frame of the carriage movement. The third method for the determination of the take-off speed utilizes an acceleration recorder. The method with the recorder involves registering a change in the accelerations when the take-off carriage is being accelerated by a system fixed on the carriage or the accelerated object. The article presents the methodology of dynamic tests of object acceleration on a launcher, necessary for the determination of speed with the mentioned methods. Selected results from actual tests with the use of the 01/WS/2015 launcher, which is an element of the ZOCP JET2 set, were presented. The test results are presented in a tabular form. The methods for the determination of the take-off speed were compared on the basis of performed tests. Based on the obtained results, the factors impacting the accuracy of each of the methods were identified.