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3D RoboticsPermalink Reply by Chris Anderson on October 8, 2008 at 4:38pm

I love the iBlue 747. $69 and it's got Bluetooth, too:

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Permalink Reply by dincer hepguler on October 9, 2008 at 2:37am

there is also a very cheap and good working gps logger at Adafruit at $19.50 ...

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3D RoboticsPermalink Reply by Chris Anderson on October 9, 2008 at 3:00am

Just to be clear, the Adafruit one requires a GPS and a Decimila, so that's $100 easy.

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Permalink Reply by Julian on October 9, 2008 at 5:13am

Since the RVOSD has a GPS just like the one required by the GPS logger Dincer specified at Adafruit, could i make a sort of Y cable spliter to send the GPS positional data to the logger and the RVOSD at the same time?

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3D RoboticsPermalink Reply by Chris Anderson on October 9, 2008 at 12:40pm

No, I don't think so. That's a serial connection, and you can't just multiplex it with a y cable. There might be a way to turn the Adafruit GPS logger into a a GPS repeater and connect the OSD to that, but it's a lot of coding to save $65.

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Permalink Reply by dincer hepguler on October 10, 2008 at 12:11pm

sorry Chris, you are definitely right, it is a true dumb of me... :)

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Permalink Reply by Julian on October 9, 2008 at 3:25pm

Yeah, thats true, so the iBlue 747 it is

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Permalink Reply by Edan on October 12, 2008 at 7:26pm

This model looks pretty good too. Cheap.



http://www.buygpsnow.com/Canmore-GT-730F-USB-GPS-Dongle-with-A-GPS-...

Edan

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Permalink Reply by Jack Crossfire on October 12, 2008 at 8:31pm

Sadly my broken spare parts GPS logger no longer gets any use, despite having an easy fix. It was originally for measuring running speed during the "Hillary revolution" but since She lost, there's simply no application for it.

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Permalink Reply by Squalish on January 10, 2012 at 3:01pm

Another facet to this question: Drones specialize in low-altitude, high-resolution remote sensing.

Evaluating these remote sensing technologies requires not just the track of the vehicle, but very solidly constrained GPS points on the ground.  Ground Control Points attached to visual targets need to have their position mapped to the best accuracy affordable.  Currently, our lab uses an incredibly expensive mapping-grade GPS unit by Trimble that can pretty reliably give 1m accuracy in seconds, but getting every point down to 0.1m or so with postprocessing requires 10 minutes of waiting per point.  When there are significant obstructions, like trees, it's even more difficult.

I'm looking into whether it's plausible, instead of using a single expensive unit, to use dozens of very cheap loggers spread out over the area of interest, attached to visual targets.  It is basically inevitable that some of them get stolen, so cheap is highly beneficial.  The idea would be to leave them all attached to their targets for hours or perhaps even a day, and then average their position later to get high-precision results.

My concerns are price, and whether this would statistically bias the positions in some way.  When you get to this level of precision other effects start to pop up...  I'm currently struggling with the existential meaning of the WGS84 datum with/without WAAS correction, and whether orbital & physical changes in the Earth would allow generally repeatable measurements.

So what is state of the art, more than three years later, in ultra-cheap, long battery life, basic WAAS-corrected GPS loggers?

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Permalink Reply by Squalish on January 10, 2012 at 3:34pm

The default entry point is presently the $60 Holux M-241.

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