The main components of satellite GPS tracking devices are a transmitter, a communication modem and an antennae. This unit, installed to the asset, communicates with the satellite at set intervals to identify the GPS coordinates, and transmits this information, either using the same satellite or through GSM network to a modem installed in a computer anywhere in the world. The control device holding the modem reveals the GPS coordinates at the click of the mouse. Users may program the GPS device to direct the GPS coordinates and other information to the management software provided by most vendors, or any other customized application.
Mobile and Satellite Tracking
Ordinary GPS systems allow route planning, but do not incorporate a communication modem to transmit location information, and as such do not allow real-time tracking to determine the movement of assets, or allow the assets to communicate in emergency. Cellular-based systems remove this handicap by using GPS satellites to acquire the vehicle’s position, and incorporating a communication modem to send real-time location information using either radio frequency or cellular networks. GPS tracking devices that rely solely on cellular networks however still turn incommunicado in remote locations where cellular networks do not penetrate. Satellite based GPS systems go a step ahead and offer uniform and reliable coverage anywhere in the globe - be it the North Pole or Sub Saharan Africa.
There are many satellite based GPS tracking providers, and all of them subscribe to different satellites such as Iridium, Inmarsat, Obrcomm, and others. The Iridium system is the largest fully meshed satellite network constellation in the world, consisting of 66 low-earth orbiting (LEO) cross-linked satellites. One popular device is Satworx RST430, commonly known as the IridiTrack, using the iridium satellite network This device contains 18’ (6m) of cable, lightweight or compact antennas, for marine, aero, vehicle or fixed depending on the need, and the Transmitter containing the modem, with an internal 16-channel GPS.
The latest dual-mode satellite/cellular systems combine the secure and uninterrupted satellite communication with the high bandwidth and cost effectiveness advantages of cellular data transmission. Such devices have intelligent message routing capabilities to switch between cellular and satellite networks seamlessly, operating on cellular networks whenever possible and switching over to satellites when cellular coverage goes off.
One good example of such a dual powered device is GlobalTrack’s DUO-900 integrated satellite-cellular terminal that uses the local GSM network when in a GSM/GPRS coverage area or Inmarsat IsatM2M global satellite service when GM network does not work. When in cellular range, the device sends frequent, cost-effective updates using GPRS, and when in satellite mode, it maintains a live reporting interval and limits to sending critical updates, storing high frequency messages for transmission when returning to GPS mode.
Application in Fleet Managment
One common application of satellite GPS asset tracking is in fleet management. GPS powered vehicle navigation systems use GPS satellites to acquire the vehicle’s position and display it on a digital map. Organizations using GPS tracking for their fleet of vehicles can:
- Track the exact position of the vehicles, allowing for better planning and estimation of delivery of pick-ups
- Set up geofences that issue alerts when vehicles move out of designated zones, or stray into prohibited areas
- Plan and track the most optimal route, saving considerably on fuel costs
- Group trucks according to specific criteria such as type and location
Real Life Case Study
One real life application of fleet tracking using satellite GPS is at Railways Africa (ARC). ARC faced difficulty tracking and monitoring the location and status of the fuel tank cars once they left the station, and while on route to the destination. Location information provided by local rail operators reached the control office twenty-four hours late, and became irrelevant by the time. Moreover, cellular lines did not cover the entire length of the track. GlobalTrack, a leading GSM technology provider offered its BAT-340 tracking device
The battery-powered BAT-340 device, installed on a mount atop each tank car using special brackets, calculates its position using information from GPS satellites and sends the information to GlobalTrack’s servers through Inmarsat satellites every six hours. GlobalTrack’s secure web-based application pinpoints the exact location, speed and direction of each individual tank car. The batteries may last up to three years without recharging or replacement
Satellite GPS tracking provides ARC with a host of other advantages:
- It pinpoints current location information of each tank car, allowing the company to inform each client exactly when their shipment will arrive. It also allows setting virtual perimeters and geofences, to inform customers when their shipment, for instance reaches within ten kilometers of the destination. Such reporting and alters service sets it apart from competition and increase customer satisfaction.
- It locates empty tank cars, to get them back on the line to transport products, improving asset utilization ratio remarkably, and by extension profitability.
- It allows setting up geofences to track the time spend at rail stations and at border crossings, to determine expected run-times, increasing scheduling greatly
- It allows viewing real information related to location, distance traveled, travel times, direction of speed, and more, and historic data related to such parameters, to generate reports tailored to specific needs. Such analytic data allow for better planning and efficiency in operations.
- The on-board GPS accelerometer notifies owners could whenever their wagon starts and stops, alerting to any unusual or unscheduled stops.
The ability to move trains faster alone allowed ARC to recover its initial investment within four months. The increased customer satisfaction and value came as extra bonus.
- “iridiTrak - RST430 GPS Satellite Asset Tracking.” http://www.satworx.com/iriditrak-rst430.php. Retrieved August 20, 2011.
- “Why choose dual-mode satellite/cellular service for mobile resource management applications.” http://www.globaltrack.com/resources/White%20Paper%20Satellite-Cellular%20Services.pdf. Retrieved August 20, 201.
- Image Creditr: flickr.com/publik15 under CC 2.0 license
- “Satellite Tracking.” http://www.globaltrack.com/resources/Case%20Study%20-%20RailwaysAfricaNov2010_ARC.pdf. Retrieved August 20, 2011.
- “Vehicle Tracking & Asset Tracking: Satellite / GPS.” http://www.satwest.com/v/satellite_vehicle_tracking_gps.html. Retrieved August 20, 2011.