Went with my parents on Sunday to visit relatives in the unfamiliar territory of Sonoma.
Setting off from Palo Alto in my father's Prius - an earlyish (2004 or so) NHW20, with fancy built-in nav system - I was in the navigator's seat, on account of being the one most likely to be able to operate the car's nav system. And, of course, I had my Magic Elf Box to fall back on.
After some poking, I managed to get the address punched in. It promptly told us to head for 101; my father, meanwhile, was making for 280. I got tired of being told to turn around, and found the "suspend navigation" button.
A few blocks later, as we headed west down Oregon Expressway, I noticed that the nav display had us several miles south, in Mountain View, near Rengstorff Avenue.
By the time we reached 280, the nav system was firmly convinced that we were in Boulder Creek, going cross-country through the redwoods in the general vicinity of 9.
I couldn't find any button for "please reassess our location and report back when you have a clue."
Somewhere around Hillsborough it came to its senses. When I noticed that the map display now matched the surroundings, I re-enabled navigation, and it worked OK the rest of the trip.
Glad I wasn't relying on it.
I remember in the old days of standalone GPS it took quite some time for the system to acquire enough satellites to get a good fix.
Since I've been using smartphones for navigation, they almost always find the satellites much faster. I think it's due to using Assisted GPS, where the GPS system gets a table off the network to help it start looking in the right location instead of searching the entire sky.
Posted by: philip.ngai | Tuesday, 20 January 2015 at 12:14
I still have an old standalone Magic 8 Ball that I use in my car. Normally, it rides in the glove compartment, remembering having been put there in my driveway.
If I take it out in some other location and power it up, it continues to think it's in my driveway for the couple of minutes it takes to find some satellites and get a fix.
The Sunday adventure, though... the GPS woke up knowing exactly where it was, tracked our route correctly for a while, then after a couple of minutes decided it was somewhere else, and got increasingly wrong for the next ten minutes or so.
So, there must be something wacky with that particular nav system, or with Toyota's software. It may be old, but it's recent enough that it ought to work better than that.
(Yes, the location-enhancement tricks used by smartphones are a big help in getting a quick fix, and in keeping power consumption down - but there have also been big improvements in standalone GPS receivers the past several years. Look at the specs on some of the new economy-model modules, and compare to those of a few years ago: the progress is impressive.)
Posted by: Eric Wilner | Tuesday, 20 January 2015 at 13:10