Joined: 18 Jun 2008
Location: Porto Alegre, RS, Brazil
|Posted: Fri Nov 25, 2011 7:51 am Post subject: Tracks and points displayed out of place
|Something weird happened today (all maps involved were downloaded from Google, calibrated by myself way back when my Palm T|X was alive, and toroughly verified by countless passages using the Palm T|X, a Nokia 6120 smartphone and my new friend Samsung P1000 tablet on the southward trip).
I started the trip back home enjoying PathAway high precision at a very detailed map (street level). Auto zoom was off, so as soon as I got over map edge, I touched zoom out button to bring next map. To my surprise the purple arrow appeared completely out of place, in the opposite margin of the wide Patos Lagoon. I was travelling on BR-116 and the arrow show up near BR-101, some 50km to the East! Since this map north border was pretty near, I waited to see if the next map would be ok, but when I called it the error was almost the same.
These two maps were the same scale when I printscreened them but ended up a little bit different when calibrated. The southern one shows 266km wide and the northern one 268km wide. I know there is an error in their calibration but this error is much less than 50km.
When I had to stop for an ongoing lane maintennance I decided to force displaying my position in some other maps using the Data>Maps menu instead of zoom buttons. To my relief, calling the very same map by this method corrected the error, and I finished the trip without further incidents.
At home I tried to reproduce the problem before ressetting that track (remember I am not able to find saved tracks) but everything seemed perfectly into its place, so you could call me a fool. But wait! How can the End point show up at the middle of the water?!? Can you see it in Foto0011? You can check by yourself, final odometer 200km, but the distance between Start and End is roughly 56km by the map scale as recorded by Google Map at the lower left corner. This was the only clue that something weird happened.
I don't know if it can be of any use because now the tracks are ok, but please find attached:
Foto0010.jpg - first map to show offset track (notice 266km width at lower right corner);
Foto0011.jpg - northern continuation of prior map (268km width);
Foto0012.jpg - wide area map for location purposes;
Foto0013.jpg - same as Foto0011 but with portrait orientation to show from Start to End.
Just a P.S. question: Should map width be the same 268km regardless of screen orientation (portrait x landscape) or should it be higher when landscaped than when portrayed?