TrekBuddy

motty-V · Joined: 06 Feb 2009 Posts: 3

Hi,
I've made a map that has a UTM grid printed on it and successfully calibrated it with OziExplorer full version (more than 2 points used for more precision).

I used TB cutter to slice it which seemed to work fine. My problem is that when I used UTM coordinates in TB and I align the cross hair on the UTM grid of the map, there seems to be a 200 meters offset in vertical axis. The horizontal axis seems ok.

From the the info->technical menu TB seems to recognize the NAD Datum properly.

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

motty-V · Joined: 06 Feb 2009 Posts: 3

Here is a link to my map.
http://www.mediafire.com?sharekey=bbd91c22702d58f2d6baebe61b361f7ce04e75f6e8ebb871
Thanks.

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

Any chance you have Settings->Basic->Coordinates: UTM? Try Map Grid instead.

motty-V · Joined: 06 Feb 2009 Posts: 3

Yeah that's exactly it... I tired Map grid and it works fine.

I guess I misunderstood the coordinates setting. I tought one would use UTM coords for UTM maps.

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

Yes it is a bit misleading... it should really be called UTM / WGS-84.

MEH · Joined: 24 Aug 2008 Posts: 22 Location: Portland, OR USA

I'm sorry but I don't quite understand.
I have almost the identical MAP info as motty-V, that is, NAD 27 Conus.
But when I try to save that to TB configuration it won't stay.

Yes, I change the default datum option to NAD 27, click OK.
Then save the "basic" menu. TB says configuration updated.
If I go back and check the settings it will change to AGD 66.

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

@MEH What device are you using? It sounds weird that datum selection gets screwed.
Anyway, for NAD 27 / UTM map to work correctly you need proper calibration (Ozi format - contains both projection and datum info), and with such calibration these options in Basic are ignored.

MEH · Joined: 24 Aug 2008 Posts: 22 Location: Portland, OR USA

I'm using a Blackberry Bold 9000

Here is the map info from OZI:
OziExplorer Map Data File Version 2.2
KaneGulch_o37109e8
D:\USGS maps\Utah\NaturalBridgesNatlMnt\KaneGulch_o37109e8.tif
1 ,Map Code,
NAD27 CONUS,WGS 84, 0.0000, 0.0000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,(UTM) Universal Transverse Mercator,PolyCal,No,AutoCalOnly,No,BSBUseWPX,No
Point01,xy, 0, 0,in, deg, , ,, , ,, grid, 12,587480.06494634,4165371.9594923,N
Point02,xy, 5226, 6748,in, deg, , ,, , ,, grid, 12,600223.14334634,4148917.6362923,N

So, as long as I use TB cutter on the map and the tif file I should not have to fuss with the settings in Trekbuddy?

Also, I use 7zip to tar all the files together before loading into the TB map directory.

How would I check to see that TB is using the correct datum and projection for these files?

Thank you!

kruch · Site Admin Joined: 02 Jul 2006 Posts: 5097

The Datum option in Basic settings is in effect only when map calibration does not provide datum information (eg. MapCalibrator uses such format, .gmi).

So in your case, there is no point fussing with it.

Using TBcutter is (should be) safe - it does not modify calibration file.

To verify that TB interprets calibration properly, check Map info in Info->Technical.