"Creating computer software is always a demanding and painstaking process -- an excercise in logic, clear expression, and almost fanatical attention to detail. It requires intelligence, dedication, and an enormous amount of hard work. However, a certain amount of unpredictable and often unrepeatable inspiration is what usually makes the difference between adequacy and excellence." (From the Unix "fortune" program.)
While most of the software I create is done as a personal hobby, some is of enough general interest to warrant release to the public.
My first commercial software application was The UoSAT Data Capture And Display Program, a telemetry and data capture program written for AMSAT North America in 1991. This program was designed in the late 1980s as part of a low-cost satellite ground station designed around a Commodore 64 home computer to decode and analyze the "living conditions" on-board the University of Surrey's OSCAR-9 and OSCAR-11 satellites. The program was written entirely in hand assembled machine language (6510 processor), and even decoded DCE (Digital Communication Experiment) information frames transmitted by OSCAR-11. (OSCAR-11's DCE was the precursor to today's "Pacsat" store-and-forward communications protocol.)
The following is a small sample of data captured from the UoSAT-2/OSCAR-11 spacecraft using this software:
* UOSAT-2 OBC STATUS INFORMATION * DIARY OPERATING SYSTEM V3.1 SMH MLJM MSH Today's date is 5 /5 /90 (Saturday) Time is 1 :47 :17 UTC Auto Mode is selected Spin Period is - 274 Z Mag firings = 0 + SPIN firings = 3 - SPIN firings = 1 SEU count = 6 RAM WASH pointer at E20D WOD commenced 5 /5 /90 at 0 :0 :9 with channels 10 ,11 ,19 ,29 , Last cmnd was 109 to 0 , 0 Attitude control initiated, mode 1 Data collection in progress Digitalker active
Archives of satellite telemetry and digital news broadcasts received from OSCAR-9 and OSCAR-11 satellites through the use of this software is available toward the bottom of the OSCAR-11 News Archive Page authored by Clive Wallis, G3CWV.
The funds received from the sale of this and other AMSAT-NA software is applied directly toward the construction of amateur radio communication satellites, and benefits the advancement of the amateur space program.
PREDICT is a very popular satellite tracking/orbital prediction program developed for the Linux operating system. PREDICT permits users to track satellites in real-time, or make orbital predictions in advance of their arrival. A unique voice mode allows azimuth and elevation bearings of a satellite to be articulated via a soundcard to aid a ground-based observer in locating and identifying satellites through visual means. PREDICT also provides live bearings of the Sun and Moon, as well as solar illumination conditions onboard satellites. Doppler shift, squint angle, and path loss information is also provided for characterizing radio communication paths between satellites and earth-based ground stations. PREDICT supports the PIC/TRACK and FODTrack automatic antenna tracking systems, and includes a UDP socket-based interface that allows real-time tracking data to be exported to any number of client applications running locally or remotely via a network connection. Several socket-based graphical satellite tracking display applications are included in the latest release of PREDICT.
PREDICT is currently used for satellite tracking applications at such places as the NASA/Goddard Spaceflight Center, the U.S. Naval Research Laboratory, Stanford University, and the European Space Agency. The latest version may be downloaded via the Internet for either Linux or DOS-based operating systems. See the PREDICT Web Site for more information on PREDICT software.
PacsatTools is an excellent addition to the PB/PG Pacsat communication suite by Bent Bagger, OZ6BL, and may be downloaded from ibiblio.org.
SPLAT! provides site engineering data such as the great circle distances and bearings between sites, antenna elevation angles (uptilt), depression angles (downtilt), antenna height above mean sea level, antenna height above average terrain, bearings and distances to known obstructions, path loss and received signal strength based on the Longley-Rice Irregular Terrain Model, and minimum antenna height requirements needed to establish line-of-sight communication paths absent of obstructions due to terrain.
SPLAT! produces reports, graphs, and highly detailed and carefully annotated topographic maps depicting line-of-sight paths, path loss, and expected coverage areas of transmitters and repeater systems. When performing line-of-sight analysis in situations where multiple transmitter or repeater sites are employed, SPLAT! determines individual and mutual areas of coverage within the network specified.
Applications of SPLAT! include site engineering, wireless network design, amateur radio communications, frequency coordination, communication system design, and terrestrial television and radio broadcasting.
SPLAT! has been useful in analyzing the service area of the Brookdale ATV Repeater System, the Pottstown, Pennsylvania ATV Repeater System, and the W2NJR Linked Repeater System. It has also been used to analyze the coverage of Ibiquity Digital Corporation's early digital radio broadcasts from WBJB-FM in recent years. Interest has also been expressed for use in the U.S. Army's Future Combat System. A slightly modified version is in use by NASA for developing communications link and fade margin policies for future lunar surface operations and exploration. Please visit the SPLAT! Web Site for additional information.