Back in 2011 I wrote the following in response to a question from Ralph Rogers and Bob Wilde as we sat in the Amarillo airport waiting for the prop hopper to Kearney. Most of it still seems valid to me.
July 7, 2011
GPS Telemetry for Falconry
Conclusion: GPS falcon tracking will come. Not next year. 5 to 10 is my guess.
Basic rule: Data transmissions have 1/3 the range of a “beep” for a given output power.
- Falconer’s obsession with “range” means future tags will have a GPS and a “beep”.
Executive summary: The crux of GPS falconry telemetry is the power consumption, and thus the battery weight. My estimate is a 4:1 combined improvement in current drain/ energy density is needed to make a 10 gram GPS tag possible. The weight of added electronics is minimal (1 gram). The cell phone industry is pushing reduced energy per fix. Various folks are claiming (hyping) improved (breakthrough) battery energy density. Think the transition from NiCad to Lithium Ion batteries in the last 20 years. The “next generation battery” is mighty fuzzy in the crystal ball.
(still fuzzy, 2018)
The ideal tag has zero weight, zero size and gives 24/7 real time world wide position to sub-meter accuracy forever. How soon “GPS” will be available depends on the compromises you accept (ideal=never) (25 grams, 10 miles max range, 1 fix per hour, 6 days=now, maybe).
Think how you are going to use GPS. Is it a tool for faster recovery when she has taken a tour of the county (five minute updates) or a way to check that she is in position for the flush (ten second updates). Updates burn battery. Remember, if she has cleared the county and is touring the state it’s back to beep, beep, beep (you hope). The beeper has one failure mode; the signal fails to get to the receiver. GPS has two failure modes; the tag fails to acquire satellite data, and/or the radio link fails to get a solid signal to the receiver. Note: The altimeter feature can take some of the fun out of lying to your buddies about her pitch.
The questions to ask as the technology progresses toward some version of “acceptable” GPS tag are:
- What is the maximum acceptable weight?
- What is the minimum acceptable battery life?
- What is the minimum range I can live with? (assume a beeper for long range back up)
- How long am I willing to wait between fixes?
- How much am I willing to pay? (needs a beep receiver and a data receiver, or one that does both)
- Does it have to do moving map, or will a precise direction and distance do?
GPS wildlife tags of 10 grams using solar cell power are industry standard. They record GPS positions and download via satellite or cell phone daily or weekly. Not a viable falconry (or dog) solution.
Summary: Not soon and far from perfect. Think about the compromises you consider acceptable. Pass your personal “minimum to make it worth the cost and effort” along to the various transmitter makers. Expect no miracles.
Marshall has made an internally consistent set of choices to answer these questions. First they have chosen a Direct Radio Link (DRL) rather than a cell phone based link. This brings almost real time update rates within the bounds of acceptable battery drain. The real time Video Game (VG) mode has been well received by the falconry community. Add the variable duty cycle on GPS, a back up beeper, an "absolutely" on moving map, plus a weight/form factor that allows leg mount and you have a unified plan.
High update rates via cell phone eat the battery in a big hurry. The European GPS systems (most of which have faded into the mist) tended to be cell phone based, making them strong in long distance recovery but poor in the VG mode.
Regards,
Thomas the Predictor
Originally Posted by Captain Gizmo
Back in 2011 I wrote the following in response to a question from Ralph Rogers and Bob Wilde as we sat in the Amarillo airport waiting for the prop hopper to Kearney. Most of it still seems valid to me.
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