TLC is a computer program that determines corrections for radiotelescopepointing errors associated with tilts and elastic deformations. These errors occur because for rotation in azimuth, a radiotelescope is mounted on wheels that move on a circular track that deviates from perfect flatness. TLC processes radiotelescope field data through smoothing, filtering, segment-fitting, trend-removal, Fourier-transform, and high-passfiltering algorithms to generate a lookup table that contains the pointing corrections. The field data in question are readouts from four inclinometers, the relative positions of the inclinometers, and readouts from an azimuth-angle encoder. Written in the Matlab software system, TLC is a user-friendly program that provides a graphical user interface that enables even an unfamiliar user to proceed, step by step, to the final result.
This work was done by Wodek Gawronski and Erin Maneri of Caltech for NASA’s Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Software category.
This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393-3425. Refer to NPO-21135.
This Brief includes a Technical Support Package (TSP).
Program Computes Pointing Corrections for a Radiotelescope
(reference NPO-21135) is currently available for download from the TSP library.
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Overview
The document presents a technical support package from NASA detailing two significant software programs developed for enhancing the performance of radiotelescopes and antennas. The first program, TLC (Telescope Control), is designed to compute pointing corrections for radiotelescopes. It addresses errors associated with tilts and elastic deformations that occur due to the mounting of radiotelescopes on wheels that move along a circular track, which may not be perfectly flat. TLC processes field data from inclinometers and azimuth-angle encoders using various algorithms, including smoothing, filtering, and Fourier-transform techniques. The output is a lookup table containing the necessary pointing corrections. Written in Matlab, TLC features a user-friendly graphical interface that guides users through the correction process step by step, making it accessible even to those with limited technical expertise. The software is available for commercial licensing through the California Institute of Technology.
The second program discussed is a GUI (Graphical User Interface) tool for developing LQG (Linear Quadratic Gaussian) controllers specifically for microwave antennas, radiotelescopes, and radar systems. The document highlights the importance of high precision tracking for antennas operating at high radio frequencies, which surpasses the capabilities of existing control algorithms. The LQG algorithm has been demonstrated to significantly improve tracking precision, as evidenced by its application at NASA's Jet Propulsion Laboratory (JPL) antennas. The GUI facilitates the design of LQG controllers, allowing users to manipulate sliders and buttons to observe antenna performance and fine-tune designs through a constrained optimization algorithm. This tool is particularly beneficial for individuals with limited control engineering backgrounds, as it simplifies the design process.
The document also includes references to previous works that support the development and application of these technologies, emphasizing the collaborative efforts of researchers such as Wodek Gawronski and Erin Maneri. Overall, the technical support package showcases NASA's commitment to advancing radiotelescope technology and improving the accuracy of antenna tracking systems, ultimately enhancing the capabilities of space exploration and research.
