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So I just got a tracking suit and will start testing it from a plane. For quicker learning I wanted to use a GPS logger and donwload the data to a computer to analyze the jumps. Does anyone have any experience with this? Do they work well at 5-10Hz at high speeds? Can anyone reccomend a model?

I have found the SJ5282 for 25€/30$ with a Venus 6 chipset which allows up to 10Hz update rate. Seems like what I want for a good price but wandering if it will actually work well. I have also read that some are innacurate at high speeds.

Thanks for any input

http://flysight.ca/

the flysight is the best plug and play model. if $$ is a big factor, the wintec 201 is an option. you must set it up on a HP computer and no support at all. once it is set up, it works perfect. good luck.

The flysight is kinda expensive, but i really found the live feedback a neat feature..

thanks all.

Well price is kind of an issue. Flysight is out of the question for now.

Since I found this GPS logger for 40$ thought I would try it. But wanted to get a reference to see if they actually work well. I have been searching and think that it can meet by criteria with the Venus 6 chipset up to 10Hz recording. Will update when I buy and use it.

If anyone else has ideas or opinions they are welcome

Keep us updated!

I was wondering how the new Galaxy S4 smartphone would do. Anyone know if someone is working on an app? It has GPS and barometric sensors.

im curious because im an inexperienced idiot whos never tracked forward in a BASE environment...........

does this software really make a difference? or is it all about taking it high and slowly farmiliarizing yourself with lines in the BASE environment, regardless of what the gps chip tells you? im honestly curious.

BASEline Flight Computer does exactly this.

You should check with Michael (Flysight manufacturer) about the Venus chipset. IIRC, he did some early testing with Venus and abandoned it. I believe that at the time Venus' claimed 10 Hz was bunk, and that they were doing a lot of interpolating using a model that isn't really appropriate to flight. At any rate, I'm sure if you emailed you'd get an honest and helpful response.

Edit: Regarding apps, it's worth noting that the GPS in your phone (every phone) sucks. Like really, really sucks. Phone GPS usually uses cell tower signals to help it get a fix at all, and takes a while to refine that fix. It'd be my last choice for recording tracks in a BASE environment.

FlySight manufacturer here. Jason's right about my experiences with the Venus 6 chipset. They claim 10 Hz, but it felt to me like there was a lot of interpolation to get there.

In contrast, the u-blox 5/6 chipset seems to have almost no lag/interpolation.

A bit of a primer on GPS... When the signal reaches a GPS receiver, it's really weak--unbelievably weak. In fact, it's well below the level of thermal noise. GPS uses some really clever tricks to work around this. One of these tricks is that it has a "model" of the kind of motion it's expecting. If it sees a different kind of motion, it chalks it up to noise and discards the data.

The u-blox chipset offers a few models that are particularly relevant to us: 1 g, 2 g, and 4 g airborne models. These models allow the GPS to anticipate 3D motion. In contrast, the usual "pedestrian" and "automotive" models expect very little vertical movement, so they aren't really appropriate for our activities.

The Wintec WBT-202 uses the u-blox 5 chipset. It's not the most recent generation, but it would be better than the Venus 6 chipset, I'd say.


The main problem with cell phone GPS receivers is the size of their antenna. This is one of the biggest tools a GPS has in combating the noise I mentioned above. Ordinarily, cell phones get around this by augmenting the GPS signal with things like distance to cell towers. However, this often doesn't work in the BASE environment in particular, and what you're left with is really not a very good GPS.

Barometric sensors are, in my mind, somewhat overrated, except in a few special cases--namely, when what you really want to record is barometric altitude instead of GPS altitude. This issue mostly comes up in paragliding competitions and such--basically, altitude as measured by a GPS means something subtly different from altitude as measured by, e.g., an aircraft altimeter.

A decent GPS receiver should be able to nail down your vertical position quite accurately. Perhaps more importantly for us, it can use Doppler information from the incoming GPS signals to determine vertical speed directly--and much more accurately than it could be calculated from, e.g., barometric altitudes.

Hope this helps. I'll be on vacation for a couple of weeks starting tomorrow, so probably won't be able to get back to this thread right way, but I'll try to check in when I get back.

Michael