db wrote on Sep 9
th, 2011 at 6:00pm:
So DD gives me a verbal description for a spot that I can understand. Close enough. Thanks BTW.
He also gives me GPS coordinates that I decided to try and look up.
Issues I encountered:
1- First I try Google Maps - it marks half way to Atikokan from where it should be.
2- The PCD yellow dot puts it too far north (I assume).
3- Memory Maps puts it even farther north. The curser doesn't show but the reading is from essentially the upper left corner.
So I grab my GPS and check things I've marked in previous years. The three I tried were all right on in Memory Map.
My question is, what an I missing or doing wrong for 1,2 or 3 above? I believe my topo is NAD83. That matter? If so how? I'll accept any clues anyone wants to provide.
It could be just a difference in format (although I use WGS 84 ... which might produce a very small difference in location). What I originally posted was in a "decimal minutes" format. Here is the same location expressed in degrees-minutes-seconds format:
N48 38 32.6 W91 39 05.4
as a UTM reference, it would be:
15 U 599336 5388582
I've checked on Google Maps and it does (eventually) provide the correct location. All I can surmise is that Google Maps is "city-centric." It gives the location of the nearest incorporated area.
So, try this (for google maps). Enter the original coordinates provided in the google tool bar (which was N48 38.544 W91 39.090). It will show an initial arrow head near Atikokan and a coordinate position of +48° 42' 31.85", -91° 39' 34.83". (Note: this is NOT the position initially provided.) Go ahead and click on the map segment provided ... it will indeed show a red pin head located in the presumed position with the letter "A" on it. Now, re-paste the original coordinates (as in, NO! I REALLY mean that spot). It will not relocate to the new location, but if you scroll down to McAlpine lake there will be a green arrow head at the correct spot.) You can also get the same result if you re-search once the map is on the screen.
This is not exactly good map making, IMHO!
I'll try the PCD and Memory Maps to see why you got your results, but when I created a wayppoint and edited the location (cut/paste) to show the spot, it was dead on in MM (so I suspect a format/conversion difference there).
dd