Killing Rats with GPS

techmaven writes "When Channel Islands National Park officials needed an estimated about 300 rats exterminated on the east side of environmentally sensitive Anacapa Island, Aspen Ag Helicopters got the call. The kill was necessary because the rodents, descendants of rats that reached the island by way of a shipwreck a century or more ago, were decimating the populations of two rare seabirds. And GPS helped the helicopter company do the job."

A little overstated?

[thesupraman]

An interesting article, however some of it is a some of this is a little hard to swallow...

their statenments about delivering sprays and pellets by air with an accuracy of 'within a foot' would be quite a thing to see, especially when you watch what a helicopters downwash does to items dropped from below it, and allowing for the pilots abilities (remember, the computer is not flying the aircraft here) - I think there cuold be a bit of wishfull thinking involved here, but I'm sure it looks good on the enviromental reports.

I assume they are using DGPS, which is generally available, for example look at:
http://www.navman.co.nz/oem/products/gps/rece ivers /dgps/index.html
also for a basic discussion:
http://boats.com/content/default_deta il.jsp?conten tid=2109
but this will certainly not guarantee you the accuracies they are claiming, at least not unless they are dropping the loads on the fixed beacons DGPS relies on (most provided by the coast guard in the US, also at some airfields).

DGPS is a wonderful development on GPS, but is still not that good. Interesting the russian GLONAS system is a little better (if more expensive for receivers) than GPS.

Using a Trimble System :-)

[Byter]

A Trimflight 3 system [trimble.com]. I work next to the people who designed this system here in New Zealand. And they might have even been using the GPS receiver that I write firmware for, the Ag214 [trimble.com] (Also known as the MS750). But they were probably using the Ag132 [trimble.com] which only does DGPS instead of RTK.

I'm sure this URL will be circulating around the Ag division of Trimble tomorrow :-)

Re:Remote Control

[I have nutsack]

Perhaps you would be interested in a Nüsse(tm) transportation satchel with integrated GPS function?

With such a device, one would be able to locate one's "nut sack" globally, were it ever lost or stolen.

I am confident such a device would be popular amongst those who read Slashdot, as many users seem to be living without a nutsack. [hemos.net]

If interest were high enough, such a fuction could be easily incorporated at minimal end user cost, were initial production yields acceptable.

I can guarantee they didn't kill all the rats

[mancuskc]

Rats living in the wild 'elect' a food taster, who tastes any new food, while the rest of the pack watches. If he/she becmes ill, the rest of the rats don't touch the food.

Even when living in captivity alone, rats will taste a tiny bit of new food, and see if they become ill, finishing the food if not, so the posion they used would have to be increadibly strong to kill a single rat with a single bite, or very slow acting to kill a pack after the taster has sampled it and given it the OK.

Clever little critters. I've kept domesticated ones for many years, and they never cease to amaze me with things they do or learn. You can house train them, get them to come when called, and do simple tricks for treats, just like dogs.

It is reckoned that living in a big city, you are never more than 3 yards away from a wild rat. Nuff said!

Re:A little overstated?

[morcheeba]

Although I tried to find evidence on Aspen's site [aspenhelo.com], it wasn't much use (I think they just win an award for terseness - particularily their history [aspenhelo.com]). There was some more info [trimble.com] on Trimble's website. The AgGPS 132 [trimble.com] is the receiver used - it uses satellite-based private subscription differential correction services and the public WAAS.

My initial guess was that the system computer-controlled the sprayers, so that when the GPS system detected that the aircraft was over the correct field and over a not-already-sprayed area, it would trigger the sprayers. To compensate for overlap, some individual sprayer jets may not fire so as to not re-apply over the same area.

But that thinking was all wrong. The Trimflight 3 brochure pdf [trimble.com] describes the system very well - it's a precise guidance system aimed at cropdusters-- it includes measuring the field, determining a coverage pattern, guiding the pilot through that coverage pattern (with the help of a lightbar to indicate how far off-track they are), and then doing the recordkeeping to record what was sprayed where. It interfaces to a Crophawk flowmeter [skytractor.com], but doesn't look like it controls the flow. This brochure also shows a helicopter doing application - the spray looks like a normal fixed-wing spray; I'm not sure why the downwash isn't blowing it all over!