Newbie thinks he's got it but needs to check with the pros

Questions and problems regarding map calibration and conversion.

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Joined: Thu Feb 08, 2007 11:04 pm

Newbie thinks he's got it but needs to check with the pros

Postby Nate » Fri Feb 16, 2007 2:09 am

I've spent the last month trying to figure out the best way to use my Treo 700 p as a navigation tool. I purchased TomTom Navigator 6 and a bluetooth GPS reciever. I love the TomTom...although it's not perfect.

Now I want to add the versitility of USGS maps for off-road use. I am using the Pathaway latest version for Palm. I have tried other softwares and found the Pathaway has more of the traditional Handheld GPS features than any of the others I tried. Only issue with Pathaway is getting the maps in it to use. After reviewing a couple different methods I've decided TTQV would be a good option, but even it is not perfect. So I am in the process of making my own maps.

I am using USAPhotoMaps on my laptop and have downloaded the entirte state of Nevada (I live in Nevada) USGS maps. I then use USAPhotoMaps to make a JPG of the current screen using the "Create BIG Jpg" option under the File menu. That JPG is stored on the local harddrive. I then import it into Pathaway Map Manager. I use the Calibrate tool and pick 5 points on the USAPhotoMap map and record the coordinates. I pick the same five spots in PMM and record those same coordinates. It took me an entire day to create the maps of an area I ATV in which is a ten mile by 12 mile area. Lots of small 5 mb files. I use 16 color, compressed setting and find it has decent detail. This area has consummed approximately 250 MB of the 1 gig SD card I use for the maps. It won't be long before I fill this card.

Three problems.
1. Size of maps. Other programs fit the entire US on one 1 gig SD cards. Am I doing something worng?
2. Time required to claibrate the maps. A whole day for such a small area. I want to get the entire northern half of Nevada done so I'm looking at completing this project sometime before I retire (I'm 42 now).
3. Accuracy. Most of my maps are off a little. Some are perfect. It's all related to human error. I mistype a cooridinate or I pick a spot on the map that looks similar to the spot I want...whatever the problem.,'s me making the errors.

I'm thinking about buying the entire US from Touratech. I downloaded the eval version and downloaded some ariel photos of the local area from Google Earth. Some retained the calibration perfectly while others did not. UIsing the exact same process...why did some work and others did not? I am hestitant to spend that kind of money on those maps and still have to check the calibration...since I'm not very good at calibrating.

My gut tells me to keep up with the USAPhotoMaps since I already own those maps and it seems to work...with some issues. What say you?


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Joined: Sun Mar 19, 2006 11:16 pm

Postby StuBee » Thu Apr 26, 2007 9:23 pm

Hello Nate,
This is kind of a late response..but since others read this too.

I also use USAPhotoMaps as a great way to export big images (ie greater than what is on the screen).
What I recently discovered, is that there is UTM coordinates listed in the filename.txt file of the export.

It contains just 4 lines of text corresponding to:
Top Left of Image: UTM E
Bottom Right of Image: UTM E
Top Left of Image: UTM N
Bottom Right of Image: UTM N

So instead of doing the difficult task of picking points on the can just use the above for calibration.
'course i wish Pathaway and USAPhotoMaps would get together in some venture, and just allow an export calibrated map feature.

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