New Product Announcement: GPS

[Tony James]

Hey Jim it is well past my budget for what I can afford to spend. So it will be RT and scout transmitters for me.

Hi Ken,

as you know, I'm not the type to get excited by gadgets and new technology, but I can hardly contain myself with this.
I think the interesting possibilities, as well as the practical ones, are endless.
And the fact that this is available in a standard transmitter sized package is quite amazing.

Best wishes,

Tony.

[sakerjack]

Hi Ken,

as you know, I'm not the type to get excited by gadgets and new technology, but I can hardly contain myself with this.
I think the interesting possibilities, as well as the practical ones, are endless.
And the fact that this is available in a standard transmitter sized package is quite amazing.

Best wishes,

Tony.

Friggin agreed!!!

[rrcoati]

Can you use two at once?

[Captain Gizmo]

The Global Positioning System (GPS) is a location and navigation utility using a transmit only satellite constellation. This means that the user handset is a receive only device. The receiver listens to a set of 24 satellites (plus 12 "spares") in 55 deg. inclined orbits with 12 hour orbit times. Using the Time Difference Of Arrival (TDOA) of the signals from two satellites you can compute a line on the surface of the earth that meets that TDOA geometry. From a third satellite you compute another line. Where the two lines cross is where your receiver is located. From a fourth satellite you can compute altitude. The system is reliable as long as your receiver, in this case the locator tag on the hawk (Tag) has a clear view of the sky and can see a sufficient number of satellites. Inside a building, under a heavy forest canopy, and the old "she caught a rabbit inside a culvert" trick all block reception.

GPS is originally intended as a system to aid in killing people. It is robust and redundant. Military gear must be reliable. The military reserves the authority to scramble or "degrade" the signal. That authority has not been exercised to date.

Given a clear view of the sky acquiring the GPS position and altitude at the Tag is essentially trivial. The tough part is relaying that information from the Tag to the user. The two currently available methods are Cell Phone (GSM) and Direct Radio Link (DRL) to a dedicated user handset.

Uplink to a satellite is not available with current technology. The Argos satellite uplink used for wildlife studies (Island Girl) has a delay time of days to weeks and energy demands that make more than one report a day impractical. Argos air time is very expensive.

The advantage of GSM is location anywhere on the planet IF both the Tag and the user's cell phone have coverage. GSM is a TDMA phone protocol, which in North America means AT&T or T-Mobil. The state of Montana has zero TDMA phone service. The information goes via SMS or Text Message to your cell phone with the associated delay time for exchanging a pair of SMS packets. Requesting frequent updates burns the battery in a hurry.

DRL is best at real time (delay in seconds rather than minutes) and can support streaming data on a viable energy budget. For a given transmitter power data can travel 1/2 to 1/3 as far as a beep. DRL is better suited to the "convenience" mode but needs a Beep to back it up for longer range recovery mode. DRL has the same problems with dropping behind a hill as a Beep and the same solutions(get the receive antenna up high, use a Yagi). MRT is quoting 3 miles range down and dirty and 15 miles range line of sight.

So GSM is better at long range recovery (cell phone coverage allowing) and DRL is better at the convenience mode (radio propagation path allowing).
Use a back up Beep in both cases.

The Marshall and Martin systems are DRL, and require a dedicated receiver. In the case of the Marshal the receiver (Pocketlink) talks to your smart phone to give display function. The Martin appears to be an all in one receiver/display.
The ByMap and Ledesma systems are GSM and can use any TDMA smart phone as the user receiver/display.
The Microsensory Tag is both DRL and GSM. It requires a dedicated receiver/display in DRL mode.

[Captain Gizmo]

The Martin Systems says "up to 16 falcons at once".

Any GPS Tag system that is cell phone based is unlimited, each Tag has it's own phone number. Sending an SMS and Receiving an SMS from multiple phone numbers may take a bit of time.

For a Direct Radio Link (DRL) system (Marshall, Martin, and Microsensory) it is just a matter of software. The dedicated receiver could use either separate frequencies for each Tag or the Tags could each have a digital identifier on their data packets.

As to doing real time graphic displays with multiple tracks on screen, again it is all software.

[rkumetz]

Any GPS Tag system that is cell phone based is unlimited, each Tag has it's own phone number. Sending an SMS and Receiving an SMS from multiple phone numbers may take a bit of time.

For a Direct Radio Link (DRL) system (Marshall, Martin, and Microsensory)

Keep in mind that a GSM based system IS limited by your budget. The transmitter is essentially a cell phone so it needs to have a SIM card that is active whether it is prepaid or has a "plan". If you get a super cheap plan with a limit on messages then you may want to crank down the update rate a lot or you risk running out of messages on a prepaid SIM card before you get your bird back.

So that is another factor to ponder when deciding on a direct link vs GSM. There is no recurring cost on the direct link (other than batteries)

[BestBeagler]

all the other GPS transmitters I have seen are HUGE. I would never put one on any bird other than an eagle maybe. They just look UGLY.

I would choose a small battery and short life span over a huge transmitter and a longer life. I see this as a VERY useful tool (not just a retrieval device) that will revolutionize longwinging (if it works as good as they say). I would also never use it as a solo unit and have a back up transmitter (forces me to do the right thing ) If it works as good as advertised I see it as worth every penny.

[JRedig]

all the other GPS transmitters I have seen are HUGE. I would never put one on any bird other than an eagle maybe. They just look UGLY.

I would choose a small battery and short life span over a huge transmitter and a longer life. I see this as a VERY useful tool (not just a retrieval device) that will revolutionize longwinging (if it works as good as they say). I would also never use it as a solo unit and have a back up transmitter (forces me to do the right thing ) If it works as good as advertised I see it as worth every penny.

Which ones are huge? I've seen a few, size doesn't concern me, weight does.

[falcon56]

all the other GPS transmitters I have seen are HUGE. I would never put one on any bird other than an eagle maybe. They just look UGLY.

I would choose a small battery and short life span over a huge transmitter and a longer life. I see this as a VERY useful tool (not just a retrieval device) that will revolutionize longwinging (if it works as good as they say). I would also never use it as a solo unit and have a back up transmitter (forces me to do the right thing ) If it works as good as advertised I see it as worth every penny.

Issac,
Curious, how you perceive this unit is going to "revolutionize longwinging"? Granted one will be able to see a flight pattern on an I pad, I phone etc. know pretty precisely how fast, how high, where the bird went, but it will not at all change the manner in which a person flies a falcon or hawk, or how the bird flies. When you look at the meat and potatoes of flying any bird, one still does the same basic things, this GPS unit just adds information, won't make the way a bird flies any better or worse. If the argument is that one can better time a flush by looking on a screen to judge position, one will spend more time looking at the screen, than watching the bird fly, which personally is what gives me the enjoyment-watching the bird fly. This is a nice tool, but the only thing revolutionized will be how accurate the flight can be analyzed when the bird is back on the fist.

[jmnucci]

I think regardless of what GPS technology is available right now, or in Sept., now that Marshall has entered the market we will see all the advances we've been dreaming about come to fruition in the next few years. The competition got turned up a few notches.