D-STAR Position Reporting System (D-PRS) utilizes the low-speed data stream of the D-STAR digital voice mode to transmit GPS NMEA sentence formatters. The standard was published in 2001, the result of three years of research funded by the Japanese government and administered by the JARL to investigate digital technologies for amateur radio.
A D-STAR radio can transmit from one to three NMEA sentence formatters when connected to a GPS receiver. The transmission can occur simultaneously with a digital voice transmission and as a periodic beacon.
Interoperability with APRS
An adjunct to the javAPRSSrvr called DStarInterface converts received D-PRS data to the APRS format and sends it through the Internet to the APRS-IS. This software, written by Pete Loveall, AE5PL, can also send and receive APRS formatted data with APRS client software that has been interfaced with the DStarTNC2 program, also written by Loveall. This provides full interoperability with APRS when used in conjunction with an APRS I-Gate.
The DStarInterface can be setup to monitor a D-STAR repeater or used in a stand-alone application.
D-STAR users that wish to utilize the DStarInterface to view their position on findu.com or jfindu.net should add a check-sum to their TX Message field. This improves accuracy and is a requirement for conversion with DStarInterface or DStarTNC2. A check-sum calculator is available online at http://www.aprs-is.net/dprscalc.htm.