Signal processing hardware and software applied to the development of a real-time infrared mission simulation test capability

The Arnold Engineering Development Center (AEDC) Scene Generation Test Capability (SCTC) program has completed the development of a laser based Direct Write Scene Generation (DWSG) facility that provides dynamic mission simulation testing for infrared (IR) Focal Plane Arrays (FPAs) and their associated signal processing electronics. The AEDC DWSG Focal Plane Array Test Capability (FPATC) includes lasers operating at 0.514, 1.06, 5.4, or 10.6 /spl mu/m, and Acousto-Optic Deflectors (AODs) which modulate the laser beam position and amplitude. Complex Radio Frequency (RF) electronics control each AOD by providing multi-frequency inputs. These inputs produce a highly accurate and independent multi-beam deflection, or "rake", that is swept across the FPA sensor under test. Each RF amplitude input to an AOD translates into an accurate and independent beam intensity in the rake. Issues such as scene fidelity, sensor frame rates, scenario length, and real-time laser beam position adjustments require RF control electronics that employ the use of advanced analog and digital signal processing techniques and designs. By implementing flexible system architectures in the electronics, the overall capability of the DWSG to adapt to emerging test requirements is greatly enhanced. Presented in this paper is an overview of the signal processing methodology and designs required to handle the DWSG requirement. Further, electronic design techniques that enabled the system to be implemented within program cost constraints will also be presented. These electronic designs include a broad range of disciplines including digital signal processing hardware and software, programmable logic implementations, and advanced techniques for high fidelity RF synthesis, switching, and amplitude control. Techniques for validating electronic performance will also be presented along with data acquired using those techniques.