This follow-on project from a client had S&ST looking in greater detail at a Cross Ambiguity Function (CAF). This 3-dimensional Time/Frequency surface is defined only as a grid of points. Determining the actual CAF peak requires precision interpolation techniques.
A variety of scenarios were tested to determine the best interpolation method for each scenario. This was done by building a software simulation of 30 different interpolation methods and then comparing the statistical results. This allowed the client to use this versatile software tool only once for each scenario. Some of the specific items addressed included:
1st and 2nd derivative interpolation
Anti-aliasing filters
Continuous Function analyses
Cubic and Bi-Cubic Spline fits
ejwt Time Domain Shift/Hunt
Polynomial/Parabolic direct fits
Precision Data Smoothing
Real and Complex 2-D FFT methods
Short-Time Fourier Transforms (STFT)
Sinc Squared
Stein's Method
System Simulation and Modeling
Wavelets
Windowing
Along with ongoing faxes of significant findings, a final report was provided along with magnetic media for easy inclusion of graphics or text in client reports. By using this cost and time effective tool, some clear choices quickly emerged for the various scenarios.
Company representatives have expressed appreciation for this effort and the client later awarded us follow-on contracts. This client can be contacted, with prior approval, regarding satisfaction with the services of Space & Signals Technologies.
