August 04, 2011

Buying the right GPS

It's been easily ten years since I bought my last GPS. The last time I bought a GPS, it was a handheld for route tracking, so I could overlay it on a topographic map and "see" where I'd been when I returned from wherever I was. At the time I didn't know much about the operation of a GPS, or what features I should be looking for. I do remember I was fleeced by the manufacturer by needing to buy proprietary cables and proprietary software to synchronize it to my computer, and remember vowing never to do that again.

This time my requirements are different. I'm going to assume that in my travels I have a laptop or other portable device to do the "heavy lifting", regarding holding the maps and showing the route or if I need to see an "overhead" view, so a handheld GPS with a screen wasn't needed. I opted for Bluetooth over USB for connectivity, to get rid of cord clutter in the car, as well as allow multiple devices to use the same GPS coordinates.

Those features alone didn't narrow down the list very much, so I started to look into the rest of the techno-babble the marketing teams were pumping out. The number of paralell channels kept coming up, and seemed rather amusing; there are ~31 GPS satellites orbiting the earth, so why would you need to track 66 of them, and use it as a selling feature? Well... according to the manufacturer, those 66 channels can always be coming "in" or "out" of sync with satellites as you move around, so while you'll never see more than (say) 10 birds overhead at the same time, it will always be acquiring the next one, and have spare channels to do it with.

That still didn't limit the number of GPSes I was choosing from, but I started to see trends regarding the number of channels, they seemed grouped into 12, 20, 32, 44 and 66 channel models. But why? Well, I discovered the "brains" of the GPS is a chipset, there are few companies in the world that make different chipsets, so the major brands all use the same handful of chips, repackaging them in their own branded fancy GPS units. You'll frequently see the SiRF and MediaTek (MTK) chipsets mentioned, but even those major vendors are always innovating and coming out with more recent chipsets with better features. So which one to choose? Guessing that the latest chipset would use the lowest power, have the most features, and after comparing specifications to make sure the latest chipset wasn't 'trimmed down', I picked the MTK MT3329 chipset. It was the most recently released chip, and seemed to have the best features (on paper.)

Going with that, I had a much smaller pool of GPS units to choose from, and the Holux M-1000C seemed to be the best price with the most features.

It should be here within a week, and after my next trip I'll need to post a proper review of how it actually performs on the road and in the bush.


No comments:

Post a Comment