THE BASIC SYSTEM COMBINES DEAD RECKONING AND MAP MATCHING TECHNIQUES THAT DEVELOP ACCURATE VEHICLE LOCATION INFORMATION. VEHICLE HEADING AND DISTANCE DATA ARE FORMATTED WITH CODED MESSAGES IN THE VEHICLE DATA PROCESSOR AND TRANSMITTED IN DIGITAL FORM TO THE BASE EQUIPMENT DURING A TIME SLOT DESIGNATED FOR EACH VEHICLE. THE TIME SLOT IN WHICH EACH VEHICLE TRANSMITS IS REFERENCED TO A SYNC PULSE WHICH IS TRANSMITTED FROM THE RADIO FREQUENCY DATA TERMINAL (RFDT) AT THE BEGINNING OF EACH REPORT INTERVAL. DATA RECEIVED AT THE RFDT IS DECODED AND TRANSFERRED TO A DIGITAL MINICOMPUTER. NAVIGATIONAL COMPUTATIONS ARE MADE IN THE MINICOMPUTER AND THIS DATA, ALONG WITH MESSAGE INFORMATION AND CONTROL SIGNALS, ARE TRANSFERRED TO THE CONTROL CONSOLE-DISPLAY IN THE FORM OF COLORED SYMBOLS ON A MAP AND MESSAGE INFORMATION IN THE FORM OF NUMERICS. CONTROL DATA IS ALSO SENT FROM THE CONTROL CONSOLE TO THE COMPUTER IN ORDER TO SELECT INFORMATION TO BE DISPLAYED OR TO REQUEST THE COMPUTER TO PERFORM SPECIFIED FUNCTIONS. THE SYSTEM HAS A CAPACITY OF 200 POLICE VEHICLES PER UHF MOBILE FREQUENCY. THIS DOCUMENT DESCRIBES THE SYSTEM AND THE EQUIPMENT. (AUTHOR ABSTRACT)