A systems design for an operational demonstration of automatic vehicle monitoring using Loran-C

The goal of the program is to determine the benefits and disadvantages of the use of Loran-C in terrestrial AVM applications. This determination will be accomplished through on-site experiments. The specific experiments include police dispatching, EMS dispatching, highway inventory, and traffic records. These experiments will be conducted as part of normal operations in each of the application areas. There are two basic questions that must be answered in each experiment. First, does the technology work in the particular application environment? Second, what are the benefits and disadvantages of implementation? With regard to a Loran-C AVM system, the answer to the first question depends on two factors: location accuracy and system reliability. To answer the second question, changes in service efficiency and effectiveness which occur as a result of the introduction of a Loran-C AVM system will be evaluated by the demonstration. Monroe County, New York, containing the city of Rochester, was selected for the program. An experimental design for each application is presented. This includes discussion of the evaluation methodology, the measures of effectiveness, sample size, experiment duration, and fleet and dispatcher conditions. The police/EMS dispatch applications are emphasized. Alternate fleet choices are assessed in terms of both experiment design and system design implications. The preferred alternative would equip 27 Monroe County Sheriff Patrol vehicles and 10-15 National Ambulance Corporation emergency medical vehicles. Each dispatched vehicle will be equipped with a Loran-C receiver and a transceiver which will transmit position upon begin polled approximately every four seconds. The equipment at the dispatch centers will utilize raster scan interactive graphics technology for integrated display of area maps, vehicle positions and incident locations. A random access videodisk player will be used for video storage of the maps to be displayed. The vehicle positions will be displayed after conversion from time differences to geographic coordinates following smoothing of the data. The incident location, usually given as a street address, will be automatically converted using the county GBF/ DIME file (street address directory) to provide the geographic coor- dinates of the incident for display. The entire system is controlled and coordinated by a mid-range minicomputer with standard peripherals including disk and tape drives. The highway inventory and traffic records experiments are specified. Results from a Loran-C accuracy study in Monroe County are given and the anticipated results of the demonstration are discussed.