Achieving the Desired Performance from a Radar Cross Section Pylon Rotator
Authors: Mark Hudgens, Tim Schwartz, John Ward
The desire to acquire Radar Cross Section (RCS) data on full scale models poses a number of challenges to the users of pylon / rotator systems. Typically, these full scale models have significant mass but have a relatively small foot print on which it is acceptable to mount the model to the rotational flange. The challenges to be addressed in this paper include designing a rotator that will have sufficient strength to support the weight of the model and the stress generated by the overturning moment. This rotator must have a sufficiently low profile and small volume so that it will conveniently fit within the model volume but still achieve a sufficient elevation travel to meet test objectives. This rotator must still properly close out the pylon at all elevation angles to prevent unwanted reflections. Additional design considerations include the test conditions and the test environment. A rigorous test requirement can demand special engineering features to mitigate the demands of relatively high scan speeds and extended run times. Environmental concerns including wind loads, temperature, humidity, and contaminants, must be factored into the design of modern RCS rotators.
This paper presents the system design approach to address the requirements of a full scale model rotator. The paper examines consequences of selected potential design solutions and demonstrates the importance of performing trade studies.