Live Tracking
Introduction
During any search a significant amount of time is "wasted" by management and team members in determining the location of each team, the conveying of these details to base and the tracking of this information at base.
Timely location information is critical to the effective management of a search especially in terms of ensuring the effective utilisation of resources.
The Live Tracking Goals
In my view the ideal live tracking system should deliver the following:
• GPS data for up to 40 teams at 10 second intervals
• Total team weight less than 500gms, including batteries, with minimum life of 40 hours
• Will have no impact on VHF radio channels used for voice
• Will work effectively with data repeaters co-sited with SAR VHF repeaters
• Will provide for storage of GPS data while radio coverage is lost and forward when in radio range again
• Each team set will provide a "digipeat" facility
• Will allow digital communications to/from teams via a PDA type device
• PDA may display locations of all teams on a map
• PDA to allow data transfer to/from base including briefing details, lost party updates, photographs etc
• Robust and waterproof
• Built from commercially available components
• Low cost
It is unlikely that any system will deliver on all of these goals in the foreseeable future. However, the UHF option we are now working on is showing the greatest promise.
Live Tracking with Icom Radios
In February 2006 I developed a live tracking system utilising the BIIS protocol in Icom F50 radios. This provides for the input of GPS data via a modified speaker/microphone. The resulting locations are displayed automatically on TUMONZ as received at base.
This system has many advantages:
• It is simple - a special microphone/GPS unit is attached to the radio. No further changes are needed for each team.
• The power is derived from the radio battery - very easy to monitor battery status
• It is robust - no extra cables or batteries
• Provided the teams have radio comms with base the data will always be sent through
• The performance is very good. GPS lock is seldom lost even in very dense bush
The disadvantages:
• The GPS data is audible on the radio channel. To reduce radio "noise" the frequency of automatic sending of the data needs to be relatively low eg 15 to 20 minutes
• The building of the GPS/microphones is labour intensive. The equivalent commercial units are expensive at around NZ$250 each
The Icom Live Tracking system has been used on every YSAR camp during the last 2 years. It has proven to be reliable and effective. It has also become an invaluable tool for managing the teams during their training exercises.
Update (Aug 2008) At last we can now click a button on the Live Tracking software and a silent message will be sent to the selected team in the field. Their radio will automatically respond with it's current GPS location. The same software can also send a txt message to the selected team's F50 radio.
Update (Sept 2008) YSAR and the Hn SAR Group have acquired base stations - Icom F5063. These are amazing radios. As well as the extra power they allow for the Live Tracking and the base radio operator to be on the same device. It provides all of the functions of the F50, plus a heap of extras.
Update (May 2010) No further changes have been made to the system as it works so well. The change we would most like to have is the facility to display the data on TUMONZ 5. Unfortunately the TUMONZ people are not in a hurry to add that facility to T5 for us.
Update (March 2012) We are slowly switching to a smaller GPS Speaker/Mic from CRS. At $280 They are much cheaper than the equivalent Icom GPS mics at around $380. They are also smaller (the Icom mics are huge) AND they have better sensitivity. They do not have as high a waterproof rating as the Icom mics but we are keen to give them a hammering for a year or two to see how they perform. Plus we need all the sensitivity we can get.
Live Tracking 2
Update (May 2010)
Andrew Smith, has produced a system using miniature UHF data radios, a microprocessor controller and a miniature GPS module. The system includes four portable repeaters, however each field team unit also acts as a repeater.
The system has been tested over several years, during most YSAR camps, SAREX’s and SAR-Ops. In our latest tests we have been able to equip 7 teams with the Live Tracking 2 Radios. The results are impressive.
Positional data is received from each team every 5 Meters or 60 seconds (whichever comes first) for around 80% of the time. The teams usually traverse a course of at least 6 km through very dense bush during each of the tests. One of the navigation exercises even includes a traverse of the full length of the Karangahake Gorge.
The UHF radios are inexpensive and robust with a high data rate of typically 57600 bps. This high data rate means that in theory we will be able to incorporate a PDA into the system to share photos, text data and team locations.
With a miniature GPS module, the whole unit, with batteries, will be around the size of a handheld VHF Radio.
The testing is continuing, and as funds become available, we will extend the scope of the tests to allow more field teams to carry the units.
The field units, (although not in there finished form yet) currently fulfil the following criteria.
• GPS data for up to 7 teams at 5M or 60 second intervals. (whichever comes first)
• Total team weight (excluding aerial) less than 300gms, including batteries, with battery life of more than 24 hours.
• Has no impact on VHF radio channels used for voice.
• Works effectively with data repeaters co-sited with SAR VHF repeaters.
• Provides storage of GPS data while radio coverage is lost, and forward’s when in radio range again.
• Each field unit provides a "mesh networking" facility.
• Built from commercially available components.
• Low cost.
We expect the system in the near future, to provide some or all, of the following.
• Will allow digital communications to/from teams via a PDA type device.
• PDA may display locations of all teams on a map
• PDA to allow data transfer to/from base including briefing details, lost party updates, photographs etc.
• Robust and waterproof
Update March 2012 The development process has been halted for the time being. Turns out that the Digi radios that we have been using operate outside the legal band in NZ. Digi have tried but cannot make these radios conform to the tight band requiremnts of NZ. Why does NZ not align its spectrum allocations with international convention?
We are awaiting some sample radios from Digi which should operate inside that band.