Thoughts - Why Everyone Should Construct Their Own World Shoreline Vector Map
I am relaxing, listening to Boz Scaggs singing "Harbor Lights" and I am thinking about why it is so important that everybody should learn to construct their very own World Shoreline Vector Map (WSVM).
First, my regular visitors know that I use a "poor man's" mapping program called Marplot. It is free and it works for my purposes. If you follow the above link, you will wonder why someone would bother to put a world shoreline vector map into software that was designed for EPA useage. Again, it is free and it works. When you install the program you will find a Maryland county pre-loaded. I believe it is Prince William County. You will see a very busy image. As you zoom in you will begin to distinguish roads, building locations, and various other Tiger info. To build your WSVM, you must delete these layers of information. Once these layers are deleted you can begin to prep Marplot for importing of vectors to create your WSVM. I name my layers for the data I am importing into them. For example, when I created the NGA Prototype Global Shoreline (NGA PGS) layers, I named them NGA PGS ## (appropriate number associated with the file). I also create a layer group (NGA PGS Shorelines) that holds all of the associated layers.
So, lets create a NGA PGS World Shoreline. Go to NGA PGS site and download each of the 32 files onto your desktop, or other storage device. They will arrive as zipped shp files. Now for the "poor man's" data conversion secret - shptomie.exe. It is a small, efficient program that does one thing well - convert shp files into mie formats. The program downloads ready to go. You will be asked to identify, from a list of choices the name for each object. Pick one. You won't use it, but it is fun to do. Next, you select the Marplot layer. I would name them for each file. For example, file #1 would be layer NGA PGS 1 and so on. Next, and very important, name the map you will import into. My map is called World Shoreline. Each file fill be imported into this map - World Shoreline. Each file, all 32 of them, will occupy their own unique layer. Trust me, it makes for fast importing and flexibility when working with your map. Once all of the files have been converted and placed into your NGA PGS folder, located on your desktop, you can begin importing them into Marplot.
The importing process is simple and typically fast, depending on your computer. From within Marplot select from the menu - File, Import and then go into your folder and select the first mie file to import. Import it - it is a Marplot formated file! When it is completed, import the next file. Bring in all of the 32-files, one at a time, each into it's own unique layer. When they are all into Marplot , you get to define the layer.
Construct a group layer to place all of the NGA PGS layers into. Select the layer, ctl-i, select the group and enter. Do that with each layer until you have each of the layers into that group layer. Then select the group and determine an appropriate color for the lines, thickness, fill or no fill, and symbol. Then select Range and determine when to show the layer and when to hide it. Don't show names or icons. A practical range for the NGA PGS is 1-cm = 120-km. When you go out farther than that the load time is very slow.
My WSVM contains shorelines for 1:2000000 scale available from NOAA Coastlines. I downloaded by WSVM @ 1:2000000 in sections and in ARC/Info Ungenerate format, which drops straight into Marplot. But, this is another story.
PS - I realize pictures would have made this post much more practical, but - so it goes. If this post tickles your fancy and you would like to give this exercise a try and you require more info, drop me a line and I will talk you through it.
PPSS - And yes, I know that there are powerful mapping packages, some of them at little cost others quite costly, that will map rings around Marplot. Marplot works for me and I am sure it can work for others.
