I need info about the USGS Quad Maps, State Plane Coords, etc.

Factual Questions
1

At the beginning of this year, I got a new job. Before, I knew enough about quad maps, state plane coordinates, map projections, etc. With the new job, I need to know more. Much, much more.

So, could someone suggest something that I can read? I need to know about map projections mainly, and how to convert from one projection to another.

I am sure that the USGS website has some information that would be useful on these subjects, but after poking around the USGS website, I have not learned any more on the subject than I would learn by pouring over the quad maps themselves. So, unless someone has a link to an article on the USGS website, please do not tell me to “go to the USGS website.”

2

Forgot to say, “thanks in advance”

I do appreciate any information

Ficer67

3

For converting coordinates, the open source proj (http://proj.maptools.org/) is useful. Personally I compiled the library into my application rather than using the command line tool.

Somewhere in the proj library are the parameters for each state for example: wisconsin central (NAD 83):



# 4802: wisconsin central: nad83
<4802> proj=lcc  datum=NAD83
lon_0=-90 lat_1=45d30 lat_2=44d15 lat_0=43d50
x_0=600000 y_0=0
no_defs <>

Which means lambert conformal conic with
+lat_1=45deg 30min (Latitude of first standard parallel)
+lat_2=44deg 15min (Latitude of second standard parallel)
+lat_0=43deg 50m (Latitude of false origin)
+lon_0=90 degrees (Longitude of false origin)
+x_0=600000 (False Origin Easting)
+y_0=0 (False Origin Northing)

If you want to just know more about projections in general, there is:
http://www.remotesensing.org/geotiff/proj_list/
and ftp://ftp.remotesensing.org/proj/OF90-284.pdf (PDF)

Brian

4

Some of this may be stuff you already know, Ficer67, but it’s useful information for GQ. The entire U.S.A. is mapped in 15-minute quadrangles (1:63,360 scale), with all populated areas mapped in 7.5-minute quadrangles, the typical “USGS quadrangle,” at 1:24,000 scale. Such maps include details down to individual structures and fences in rural areas as of the time of mapping, and contour lines at 10-foot vertical intervals, hence making them “topographic” maps. The projection used is the Universal Transverse Mercator grid (technical information available at the link).

Since many uses to which USGS topo maps have been put do not require knowledge of altitude contours, many states also produce planimetric maps which duplicate in area the equivalent USGS quadrangle but omit the topographic contours and many of the details available on USGS maps. The Digital Raster Graphics program developed by USGS in partnership with the Land Information Technology Company, Ltd., of Aurora, Colorado has produced digital imaging of all USGS quads, and I’m forming the impression from the article that adaptation into other projections is quite possible, though I don’t know cartography well enough to be sure of this – but following up at the linked site should give you leads on where to look for further information.

5

Most mapping programs will convert between different coordinate systems, and will convert between major projections. I don’t think you’ll find much useful information about how to do it yourself, and even as a cartographer I’ve never done something like that by hand. Your best bet is to find a mapping book that talks about different types of projections and can help guide you to the best projection for the maps you want to make.

I did pick up one book a couple of weeks ago called Mapping Hacks. There was some good information in there, but I skimmed the projection chapter because I know them well enough. I would say look at Amazon for books under Cartography and there should be a good number.

I’ve just looked under Map Projection,on Amazon, as well and there seem to be a couple of different books. You might be able to find a book at a local university if you have one close.

6

I’ve needed to convert Lat/Lon (GPS, TIGER data) to whatever format the customer uses (usually UTM or State Plane)

Brian

7

I’m no geographer, but I do use GIS almost every day. My experience has been similar to the above, in that projections and projection theory are things you learn early on and then rarely apply other than by using some sort of projection converter, or conversion built into your GIS application. A couple more standalone converters are:

CORPSCON from the US Army Corps of Engineers

And Tatuk Conversion Calculator

8

ESRI, a software leader in GIS, has an extensive bibliography on their site. Here is a list based on a “map projections” search. One of their free books is called Maps and Map Projections, I think.

They also have an online course , called Understanding Map Projections and Coordinate Systems. It’s $125.

ETA - I don’t work for ESRI or sell their products; I just use 'em.

9

Thanks for the information guys. The responses posted so far constitute the best information I have ever recieved off of the Straightdope.

Ficer67

10

Please don’t pour over the quad maps. It makes them soggy and hard to read.