The Interactive Coverage Analysis Tool (iCAT) is an interactive desktopcomputer program serving to (1) support planning of coverage, and management of usage of frequencies, of current and proposed radio communication systems on and near the International Space Station (ISS) and (2) enable definition of requirements for development of future such systems. The iCAT can also be used in design trade studies for other (both outerspace and terrestrial) communication systems.

This is the type of Statistical Analysis that can be made from the output of iCAT.
A user can enter the parameters of a communication-system link budget in a table in a worksheet. The nominal (onaxis) link values for the bit-to-noise-energy ratio, received isotropic power (RIP), carrier-to-noise ratio (C/N), power flux density (PFD), and link margin (see figure) of the system are calculated and displayed in the table. Plots of field gradients for the RIP, C/N, PFD, and link margin are constructed in an ISS coordinate system, at a specified link range, for both the forward and return link parameters, and are displayed in worksheets. The forward and reverse link antenna gain patterns are also constructed and displayed. Line-of-sight (LOS) obstructions can be both incorporated into the gradient plots and displayed on separate plots.

This program was written by Steven M. Bolen and Catherine C. Sham of Johnson Space Center.

NASA Tech Briefs Magazine

This article first appeared in the September, 2007 issue of NASA Tech Briefs Magazine.

Read more articles from the archives here.