I had a similar problem with the GPS app on my smart phone. I was out on
a cycling run and suddenlyit said that I was 400 feet below ground level. It
pretty much stayed that way for about 25 minutes, then jumped up to the correct
altitude. All the time the UTM was correct, as shown on the route tracker.
It happened again a few days later. Then a couple of days ago I could
not get a 3D lock at all. Turned out the smart phone clock was way off as I
had not connected it to a wifi for more than a week. Once I did, everything
returned to normal. I obviously need to do that more often.
The clock oscillators in these things are not exactly space shuttle
quality, and the crystal oscillators used in formal GPS receivers are TCXOs
(temperature compensated crystal oscillators).
To make up for this deficiency, I instaled the ClockSync.apk application,
which synchronises the smart phone clock to an NIST or other comparable time
standard. I still have to connect it to a wifi, but I know that I'm getting
the best possible synchronisation outside of GPS.
My laptops and desk computer all have NetTime installed, which performs
the same function.
Something is not quite right here ?
Those map co-ordinates give a site almost due north of Rockport on the
North Cascades Highway ..... Highway 20...... and several kilometers
east of Concrete which in turn is a few kilometers south of Lake
Shannon. Some where I have photos of my wife and our then dog swimming
in Lake Shannon. Continue east on Highway 20 one reaches Omak and then
north on Highway 97 to cross the border at Osoyoos in BC and then north
up the Okanagan Valley to where we lived about an hour north of Osoyoos.
Chris
When the going gets weird, the weird turn pro
- Hunter S. Thompson