ALBERT

Description: The Optical Communication Link Analysis Program, OPTI, analyzes optical and near-infrared communication links that use pulse position modulation (PPM) and direct detection. The program prompts for inputs of system component parameters, modulation format and other operational parameters, background noise sources, and the desired link bit error rate. From these inputs, link margin is determined and a link design control table (DCT) is generated. The program also allows the user to save sets of input parameters defining a given link and read them back into the program at a later time. Further, the program has the capability of altering automatically any of the input parameters to achieve a desired link margin. The program provides a table of extended background sources, e.g. planets, the moon, and the sun. To compute background noise, only the distance from the receiver to the noise source(s) must be entered. This determines whether or not the whole object is in the field-of-view. The program assumes that each object is a blackbody (at 5900K) with an overall visible magnitude scaled to match the tabulated data. Also provided is a table of 19 bright stars. If the noise source is one or several of these, then only the name(s) of the star(s) are required. Noise sources that are not among those contained in the program can be entered as "additional noise sources". In this case required information includes whether or not the source is a point or extended source, its radiance (for extended sources) or irradiance, and receiver to source distance in A.U. (for point sources). The OPTI program is written in FORTRAN-77 and was designed to be used on the IBM PC and PC/AT personal computers. (Note: The 8087/80287 math coprocessor option is highly recommended for use with this program.) The program will also compile under UNIX 4.3 BSD FORTRAN-77 with minor changes. OPTI was developed in 1987.