Converting .shp (shape) files

[GeoBobC]

I have a .shp file that I'm trying to convert to something useful on my Garmin GPS. I imported it into GPSMapEdit, and the dimensions and shape are correct, but the latitude and longitude are off. I played around with the third screen ("3. Select source coordinate system") but nothing gets it entirely correct.

 

I also trying importing it into ExpertGPS, with similar results.

 

Someone told me that I also need the .dbf file, the .shx file, and the .prj file. I have all these, but I don't know how either GPSMapEdit or ExpertGPS would use them. I don't see any prompts; they both ask only for the .shp file.

 

Can anyone suggest steps I can take? Thanks.

[+mattalbr]

The software should read the ancillary files after you point it to the *.shp. Those 4-6 files together make the shapefile.

 

Open the *.prj file in notepad and check that the data's coordinate system/datums/units are what you expected.

 

Also, which state is the data representing? Some states officially use the international foot as their mapping unit (SC, MI, AZ, and a couple more I think). There's a slight difference between the two (2 feet in 1 million feet) but over large data sets it show itself if conversions weren't done correctly.

 

Matt

[GeoBobC]

The .prj file reads as follows. The state is Washington. My errors are in miles, not feet. THANKS.

 

PROJCS["WGS_1984_PDC_Mercator",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-150.0],PARAMETER["Standard_Parallel_1",0.0],UNIT["Meter",1.0]]

[+Timpat]

Bob, did you get your answer and get it to work? Not sure how GPSMapEdit works with reprojecting, if it does, but your file needs to be in feet vs its native meters as indicated in your prj file.

[Grasscatcher]

Bob,

Put all the files (XXX.dbf,.prj,sbn,.sbx,.shp,shx) into one folder, then point your import or conversion operation to that folder. Some operations ACT like they only see one file (.shp) but really they are using multiple. Some operations need more than others......I know....I know ...?????

 

Long story short, whenever working with shapefiles, just consider all the "same name" files with different extensions to be a "single" file. If I were to select a shapefile to send to you by attachment, depending on which software it was coming from, I might select a single file and when it was attached to an e-mail it might show up as 3(min, maybe up to 6) files. From other software , I might have to select all the different extensions and send as a group....and the software on your end may "see" the group but only display it as one file (the .shp)

 

I hope this helps instead of confusing the situation.

[GeoBobC]

I have yet to succeed. GPSMapEdit wants a specific .shp file, not a folder.

 

Is there a service I could send this (these) files to, to convert them for me? I could then see what I'm doing wrong. Thanks.

[Grasscatcher]

What do you want them converted to?

 

Send them to me or tell me where to find them and I'll see what I can do.

Can't promise I'll succeed but I'll try.

 

You still have my e-mail?

Edited March 12, 2009 by Grasscatcher

[Grasscatcher]

Bob,

Do this...

Create a folder, wherever, and name it XXXX

Put all your shape files with the "same name" (but different extensions) in that folder.

Now, open Mapedit and go to file,import.....and "path" to that new folder...

Mapedit will show only one file....choose "it" and you ought to be in business.

 

If you look at that folder with MS Explorer you can see all the different files with different extensions, but Mapedit recognizes that all of them create a "shapefile".

Edited March 12, 2009 by Grasscatcher

[GeoBobC]

email sent. THANKS.

[+MaliBooBoo]

GeoBobC,

 

If you still haven't got it to work, drop me a line and I can see what I can do.