Friday, November 23, 2007

Preliminary information about my GPS experience

While attending a conference in New York recently I took the opportunity to buy a GPS unit for my car. The unit I chose was the Garmin Streetpilot, c550, which has been on the market for some time and is therefore dropped in price. My impression is that Garmin is the heavy favorite in the GPS slugfest taking place now. I paid $324 at DigCity in New Jersey, which is a web store. Actually, Pricegrabber was showing a price of $284, but that may have been for a rturned unit that was no longer in stock. Over the years I have had good luck buying tech toys that have been returned. I think many people buy stuff that they simply cannot understand how to use. As long as the web store has a good rep and a good return policy you can save a bunch of money buying returned merchandise.

To go along with the Garmin unit, I purchased a downloadable "global map" of Mexico, surprisingly named "Global Map Mexico", which I think is a product of a Mexican company, but cannot pin that down. The other piece one needs is software to download and upload data to the GPS unit. That software is "MapSource" by Garmin and is free (not to be confused with the version intended for blue water navigation, which requires a payment).

I had the understanding that Global Map Mexico had detailed street information for Veracruz City, Villahermosa and Oaxaca, but if it is there, I cannot find it. The information for Xalapa is very sparse. State route 140 is shown with a few streets simply labeled "Calle de Xalapa", which confused me at first because I thought the map label meant Av. Xalapa. Silly me. Later on I looked at Veracruz City and could see many map lines labled Calle de Veracruz, obviously this is simply a conventional way of labeling streets when the detail is missing.

A thing that really surprised me was that my Garmin seems to have some basic map information for Mexico and indeed many more places. I hasten to add that there is no detail in this "basemap" until you hit the border of the US which has tons of detailed information. Just for the hell of it I asked my unit to route me to an address in San Diego, CA. Using a product feature that lets you simulate the trip, my Garmin promptly instructed me to drive to route (state road) 140. I was then led towards Perote and then into Puebla. I turned of the unit at that point because the simulation was running very slowly and my battery was getting low. I think the fool thing was going to take me through Mexico City, DF. No way, Garmin!

There does not appear to be a lot of map choices for Mexico that show "street level" detail. Nonetheless, I have discovered there is a way to use Google Earth information along with some public domain software to derive detailed maps of just about anyplace on earth. I will be reporting more on this in future posts as I climb the learning curve.