Google maps goes crazy near Google HQ

[rjf17]

I just got a car mount for my Bionic and have gotten in the habit of opening Google Maps to show the traffic during my commute. I drive down US-101 in the SF Bay Area and every day, just as I pass under another freeway near the Google Headquarters in Mountain View, Google Maps suddenly shows my car just off the freeway (near the Google offices), then switches back to my correct location after I get past the overpass, but the display is zoomed all the way in. This appears to be happening every time that I have Google Maps open when I'm passing by.

????

 

[breadnatty08]

I have this happen several times. It's especially common if the highway parallels another road. Sometimes it'll bounce back and forth, doubt the guys at Goog are messing with you.

 

[Lars]

All roads lead to google

 

[Thom]

I don't know much about GPS. I have been using it in MyTracks to map tail-trails and documenting them in the Google Maps database.

GPS is affected by location. In my simple application it was off by as much as 200' at times.

From the two preceding observations ...

The first ... near Google ... was possible caused by having the GPS signal blocks when in the underpass.

The second ... parallel road ... GPS isn't that accurate and it can be affected by location.

(Anyone know how GPS is able to measure altitude and how accurate it is?)

... Thom

 

[Lars]

Altitude is calculated if you have at least 4 satellites. 3 to triangulate a position vertically on earth. A fourth to figure a rough altitude (third dimension). It's not very accurate. The maps app can cheat and assume you are on the surface of the earth and use geo location data for altitude.

 

[amageus]

Its telling you to go visit Google HQ lol. GPS aren't exactly 100%. There is this certain freeway that I drive on and whenever I drive near this one road it would position me on that road rather than the freeway. And when the GPS signal is weak your gps radius can grow several feet or more which will throw you to the nearest road sometimes.

 

[Thom]

Altitude is calculated if you have at least 4 satellites. 3 to triangulate a position vertically on earth. A fourth to figure a rough altitude (third dimension). It's not very accurate. The maps app can cheat and assume you are on the surface of the earth and use geo location data for altitude.

Thanks.

There's an App (Altitude) that measures it both ways and reports both answers. That app shows a difference.

Do you have an idea on the range or the error from the direct measurement approach?

I know exactly where I am on the Google map when I am on a particular trail. I get to one specific area of that trail about 500' and the reported GPS location is off in the woods (by about 50'). Any ideas?

This seems similar to the parallel road observation earlier in this thread.

... Thom

 

[Yeltnerb]

Is that the 101/85 or the New Old Middlefield over crossing that causes the issue? Either way it is a GPS not being accurate issue (most likely the overpass is blocking out the signal).

If they wanted to mess with people randomly when driving past that point your directions would tell you to get off the freeway, go the the MSFT building right there and honk. Or they would tell you to go to the android building on Charleston (the one with the Android stuff on the lawn in front) and exit your car and yell "iPhones suck android rules" or something else.

 

[Frisco]

I just got a car mount for my Bionic and have gotten in the habit of opening Google Maps to show the traffic during my commute. I drive down US-101 in the SF Bay Area and every day, just as I pass under another freeway near the Google Headquarters in Mountain View, Google Maps suddenly shows my car just off the freeway (near the Google offices), then switches back to my correct location after I get past the overpass, but the display is zoomed all the way in. This appears to be happening every time that I have Google Maps open when I'm passing by.

????

They're trying to draw you closer and closer .. (cue Twilight Zone theme).