Research On Air-Ground UAV Transient Electromagnetic Data Acquisition Technology

The semi airline UAV transient electromagnetic method has become a new geophysical exploration method because of it has advantages both the ground transient electromagnetic method and air transient electromagnetic method. This method laid a large fixed source loop or long wire source on the ground, UAV as a probe platform in the air carrying receiving probe and other auxiliary information measuring devices, finishing fast high resolution measurement when arrives at the designated place low altitude voluntarily using GPS navigation. After the completion of the data acquisition task, it will automatically return to the takeoff point for the late data processing.This paper is supported by the project air-ground UAV transient electromagnetic detection system development. The author does some research on data acquisition technology basing on the existed theory of transient electromagnetic detection and the relevant design experience, it is the key technology in this system. According to the requirements of research work, firstly, this paper build the air-ground UAV transient electromagnetic data acquisition system, In order to ensure the safety of equipment and reduce the signal noise, propose a new data collect way, data acquisition was carried out by hovering in the air. Then, the author does some research on key theory of data collection, based on these theorys, a scheme of transient electromagnetic synchronous technology is developed, synchronous acquisition technology of transient electromagnetic is realized through the development of wireless data transmission module and program. The noise reduction effect of linear superposition algorithm and bipolar synchronous superposition algorithm is analyzed, and the method of peak detection is used to ensure that the positive and negative stacking times are the same. In order to generate the apparent resistivity profile, an equal interval recursive sampling method is proposed, which is compared with the fitting curve of the equal logarithm interval. At the same time, the author finishes the design of data acquisition program, this program contains setting serial port, flight point analysis, control of transmitter, stack time setting, control of NI acquisition card, signal conditioning, data processing and display and storage program, and human-computer interaction interface design. In the end, the functions of each part of the design process are verified by laboratory and outdoor test, the test results basically meet the requirements of the project.