DLG Reader Overview
DLG Reader Detailed Description
DLG Reader Prices

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DLG Reader Requirements: Pentium running Windows 95/98/2000/NT with 8 MB hard disk space, 32 MB RAM, and AutoCAD R14.


Partial display of sample DLGs included with the software. (GNIS labels are included in this graphic. See below for instructions on importing GNIS data with DLG data.)

Importing GNIS Labels with the DLG Reader

GNIS files are USGS-maintained databases that hold information about place names on the map. Importing GNIS files into the AutoCAD drawing is simple:

  • Download the GNIS file for the State your map is in. We will use Georgia as an example. (GNIS files are located at ftp://mapping.usgs.gov/pub/gnis.) Once in the proper directory, download the appropriate file, i.e., georgia.gz.
  • Unzip the file using WinZip or the UNIX gunzip utility for DOS. Rename the file with a .gni extension (georgia.gni). It is suggested you make a directory on the hard drive to keep GNIS files. You might also keep them in the same directory as the dlgread.arx file.
  • Import the GNIS labels into the current drawing. To do this, issue the command gnisin. Select the appropriate drive, directory, and file.
  • GNIS databases can be quite large so importing may take awhile. After they are imported, text labels will be in various locations on the map.

This screen lets you set the Earth Model, Coordinate System, Units, and Zone. If you do not check the Perform Transformation check box, the DLG will be pulled in with its default coordinate system (UTM, NAD27, meters). The zone will be displayed in the Set Import Parameters dialog box.

The Finished Product

Once you click on "OK" to the Set Import Parameters dialog box, the DLG Reader will begin the import process. You should then be able to view your map.


Begin the Import with the DLG Reader

Issue the command "dlgin" at the AutoCAD Command prompt. The software will take advantage of the AutoCAD demandload feature, whereby an application can "load itself" into memory when called upon to perform an action. This feature allows the AutoCAD user to have only the programs in memory necessary for the operations being performed during the session.

Using the Import Dialog Box in the DLG Reader

The dialog box that appears after the "dlgin" command is issued allows you to choose which DLGs you want to load from a list of all DLGs in the directory. This is helpful since one "map" may consist of several layers of information. Note that additional information is displayed for each layer. All DLGs in the selected directory are automatically marked for import; deselect the files you do not want with CTRL+left click. As you select different directories in the directory box, the dialog will display available files in the list box on the right. If you would like AutoCAD to automatically zoom to the area where the DLGs are being imported, you can select the "Zoom to Import Extents" check box.

Select Directory for Input in the DLG Reader

This is a typical directory list box that allows you to navigate any of the drives and directories that are currently available to the local system. This includes all "special" drives as well, for example, CD-ROMs, Jazz drives, network drives, etc.

DLG Reader File List Box

This list box allows you to select/deselect specific files in the currently selected directory. Extra information is displayed so that you can more easily decide which files you need. Note that the USGS map name, layer name, and scale are included in this information.

Setting the Projection Parameters with the DLG Reader

The parameter box allows you to set the input map projection parameters (see figure below).


Introduction to the DLG Reader

If you use AutoCAD for mapping purposes, what you have probably been doing is purchasing basemap information in DWG or DXF format and importing it over your other mapping information. Basemap information from custom data providers can be good, but expensive. When the data is available on the USGS Internet FTP server free of charge, why not use a less expensive method for putting basemaps together?

The MidTex DLG Reader for AutoCAD will be of great benefit to companies that need accurate digital information but don't want to pay the high prices that basemap providers charge. It is seamlessly integrated as a native ARX extension to the AutoCAD desktop. You can use the same exact data that companies like American Digital Cartography (ADC) use without having to pay exorbitant rates. Considering that charges are $100 for half of a 1:100K digital quad, this program can pay for itself immediately.

DLG Reader Product Capabilities

  • Create custom basemaps from 1:100K scale DLGs (freely available over the Internet or purchase 1:24000 scale (7.5' quad sheet) DLGs from the USGS.
  • Convert DLGs from their internal coordinate format into the popular coordinate systems, NAD27/NAD83, UTM/State Plane, feet/meters.
  • Import DLGs as single files or as selected files in a subdirectory. This makes it easy to pull in multiple layers as well as multiple quads.
  • Receive help from the on-line context-sensitive Help system.
  • Import names from the Global Names Information System (GNIS) databases which are also available on the Internet.
  • Create contour maps from DLG hypsography databases. Contours are drawn at proper elevations.
  • Use the layering scheme provided with the software or create your own custom layering scheme.
  • Make quality presentation maps with single- and double-line linetypes.

Using the DLG Reader

The following is a description of the steps for creating custom basemaps using the MidTex DLG Reader.


MidTex DLG Reader - create custom basemaps from DLG's

DLG Reader Category: civil engineering, GIS

MidTex DLG Reader Description

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