GPS

AlanW

Maximum Pace
Jan 30, 2007
1,214
436
103
Tokyo
#2
GPS will be right but the maps will be wrong!

I'm going to look into datum calibration to see if there's anything that can be done. Most days GPS is not accurate to 2.4m anyway so may be a non-issue.
 

Yamabushi

Maximum Pace
Jun 1, 2010
2,335
188
1,083
Tokyo (Nezu)
fudoushin.com
#3
Funny, I was wondering the same thing. Technically, they should work just fine. If there were an issue it would be that the roads and landmarks are now offset from where your GPS maps show them. That being said, given the typical margin of error of consumer GPS units it likely won't be a significant factor.

FWIW, I rode yesterday and my Garmin Edge 800 functioned and tracked normally without issue.
 

Ludwig

Speeding Up
Oct 9, 2008
871
0
36
Setagaya-ku, Tokyo
#9
I have found that GPS and maps weren't perfectly calibrated even before the earthquake. It even depends on the map - Google and Garmin UUD never coincide perfectly. So entirely possible that the earthquake has made things better rather than worse...

BTW, Garmin has a function to keep the position on (routable) roads, in case anyone is irritated by seemingly riding off the road. But it also means that when you are really off the road, the device may not show it.
 

FarEast

Maximum Pace
May 25, 2009
5,528
538
193
Yokohama
#10
Unless you have a military GPS you are always going to have about 10m diviation on them. Car Navi which has a bit more computing power than its cousins on the bike and are able to calculate that you are on "Road" by tracking the position.
 

Ludwig

Speeding Up
Oct 9, 2008
871
0
36
Setagaya-ku, Tokyo
#11
Unless you have a military GPS you are always going to have about 10m diviation on them. Car Navi which has a bit more computing power than its cousins on the bike and are able to calculate that you are on "Road" by tracking the position.
The Edge 705 is able to do this too - you just need to enable the function. It works fine and doesn't drain the battery.

BTW, when I was visiting Washington DC I noticed that the GPS was far less precise (often hundreds of meters off). Assume this is deliberate to avoid terrorists or foreign powers targeting US government institutions...
 
#12
In case of Edge 800 - the "always on road" does drain the battery ! You can visually see the "jumps"* forced on the display every few seconds and that requires battery power.

* Especially when riding on the pedestrian stroke on a major kokudo, the 800 goes in overdrive :eek::eek:!!!

The Edge 705 is able to do this too - you just need to enable the function. It works fine and doesn't drain the battery.

BTW, when I was visiting Washington DC I noticed that the GPS was far less precise (often hundreds of meters off). Assume this is deliberate to avoid terrorists or foreign powers targeting US government institutions...