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Vehicle Location / APRS. What is AVL / APRS? Automatic Vehicle Location Automatic Position Reporting System Commercial AVL – CES APRS – Amateur Radio. Vehicle Location / APRS. Vehicles Equipped with GPS Receiver Mobile Sends GPS Location Data over RF Path
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Vehicle Location / APRS • What is AVL / APRS? • Automatic Vehicle Location • Automatic Position Reporting System • Commercial AVL – CES • APRS – Amateur Radio
Vehicle Location / APRS • Vehicles Equipped with GPS Receiver • Mobile Sends GPS Location Data over RF Path • Fixed End Receives Location Data and Displays on Computer
How does GPS work? http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html http://electronics.howstuffworks.com/gps.htm
GPS Receivers • Handheld • Garmin • Magellan • Dedicated • Oncore • Receiver / Antenna Combos • Tripmate (Delorme) • Pharos • Tripnav
GPS Receiver Output • Typical output is NMEA Standard (National Marine Electronics Association) • Various NMEA Messages containing: • Location • Speed • Altitude • Direction of Travel • Time • Validity of fix • DOP (accuracy of fix) • # Satellites tracked • Which Satellites are Being Tracked
RMC Message • RMC - Recommended minimum specific GPS/Transit data • RMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68 • 225446 Time of fix 22:54:46 UTC • A Navigation receiver warning A = OK, V = warning • 4916.45,N Latitude 49 deg. 16.45 min North • 12311.12,W Longitude 123 deg. 11.12 min West • 000.5 Speed over ground, Knots • 054.7 Course Made Good, True • 191194 Date of fix 19 November 1994 • 020.3,E Magnetic variation 20.3 deg East • *68 mandatory checksum
Commercial AVL Uses • Police • Taxis / Limos • Ready-mix Trucks • Delivery Trucks • Construction Equipment • Ambulances
APRS – Basic TNC
APRS Mobile Equipment • GPS Receiver • Anything that outputs NMEA data • APRS Capable TNC • KPC3, KPC3+ • Tiny Tracker • Mobile Radio • Any VHF Mobile
APRS Base Equipment • Any TNC • Mobile Radio • Any VHF Mobile • Mapping Software • APRS + SA • WinAPRS • UIVIEW • DOS APRS
APRS Digipeaters Digipeater – Store & Forward Data Repeater RELAY – Typical home station. Lower ant height – smaller coverage area. Most home stations are set up as RELAY station. WIDE – Wide area coverage. Typically 100’ or higher tower Most WIDEs are set up as WIDE and RELAY. GATE – Digipeats from one band to another. Typically VHF to HF IGATE – Gateway from VHF to the internet.
APRS Digipeat Paths Typical mobile path : RELAY,WIDE,WIDE Do NOT use RELAY,RELAY! Typical Packet: K9SA-9>GPSMV V RELAY,WIDE,WIDE:$GPRMC, . . . . Typical fixed path: WIDE,WIDE Do NOT use RELAY,WIDE, WIDE (unless you are out of range of any WIDES) WideN-N 1st hop WIDE3-3 2nd hop WIDE3-2 3rd hop WIDE3-1 etc. Typical Packet: K9SA-9>GPSMV V WIDE3-3:$GPRMC, . . . .
Wide Area APRS (Worldwide) • Mobiles digipeat from VHF to IGATE • IGATE passes location data to internet APRS server • Server stores locations of ALL received APRS packets • Anyone worldwide can access this information • In some cases IGATES can digipeat from server to VHF
Worldwide APRS • All APRS Programs can download from server to the • computer for display on a map. • Findu http://map.findu.com/k9mot • javAPRS http://www.aprs.net
APRS Uses • Public Service / Parades • Special Events • Balloon / Rocket Launches • Bike Rides • Round the World Flights • Shuttle / Satellite Tracking • Weather Tracking • Wife / Kid Tracker