Small unmanned aircraft electromagnetic interference (EMI) initial assessment

As part of NASA's Unmanned Aircraft System Traffic Management Project, flight experiments are planned to characterize the radio frequency environment at altitudes up to 400 ft. to better understand how small unmanned aircraft system command and control links can be expected to perform in the low altitude environment. The flight experiments will use a radio frequency channel sensing payload attached to a small unmanned aircraft. In terms of the payload being capable of measuring relatively low-level signals at altitude, electromagnetic interference emanating from the vehicle itself could potentially complicate the measurement process. For this reason, NASA recognized the importance of identifying and measuring the electromagnetic interference performance of the unmanned aircraft planned for these flight experiments, a Dà-Jiãng Innovations Science and Technology Co., Ltd S1000+ Spreading Wing. This vehicle was measured in a controlled electromagnetic interference test chamber at the NASA Ames Research Center. The S1000 is a carbon fiber based platform with eight rotors. As such, the electromagnetic interference test results represent potential performance of a number of similar small unmanned aircraft types. Unmanned aircraft platforms significantly different from the S1000 may also require electromagnetic interference testing, and the method employed for NASA's S1000 electromagnetic interference tests can be applied to other platforms. In this paper, we describe the Unmanned Aircraft System Traffic Management project, the radio frequency channel sensing payload, the electromagnetic interference testing method and test results for the S1000, and discuss the implications of these results.