This metadata file describes a suite of USGS DRGs in Illinois that have been reprojected to a Lambert Conformal Conic Projection. This set is commonly referred to as "Lambert projection, collar intact." With the exception of projection, the images are identical to those distributed by the USGS. Horizontal datum is NAD27. Map units are feet. The new projection information included in this metadata file supersedes that specified at the lower left on the collar of the map image. Each image has an associated georeferencing file with a .tfw extension.
The naming convention conforms to that used by the USGS.
The Illinois Department of Natural Resources does not maintain a separate metadata file for individual DRGs. This metadata file applies to all the images in this set.
This set currently includes 7.5-minute (1:24,000 scale) DRGs.
Note that the bounding coordinates reported below are for the entire state of Illinois, not for any single quadrangle.
Illinois State Geological Survey, 1998, United States Geological Survey (USGS) Digital Raster Graphic (DRG) Images for Illinois Reprojected to Lambert Conformal Conic Projection: ISGS GIS Database file name conforms to USGS naming conventions, Illinois State Geological Survey, Champaign, Illinois.
This is a Raster data set. It contains the following raster data types:
The map projection used is Lambert Conformal Conic.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest unknown
Ordinates (y-coordinates) are specified to the nearest unknown
Planar coordinates are specified in feet
The horizontal datum used is NAD27.
The ellipsoid used is CLARKE1866.
The semi-major axis of the ellipsoid used is 6378206.4 meters.
The flattening of the ellipsoid used is 1/294.98.
USGS DRG Color Palette
Digital Number Color Red Green Blue
0 Black 0 0 0
1 White 255 255 255
2 Blue 0 151 164
3 Red 203 0 23
4 Brown 131 66 37
5 Green 201 234 157
6 Purple 137 51 128
7 Yellow 255 234 0
8 Light Blue 167 226 226
9 Light Red 255 184 184
10 Light Purple 218 179 214
11 Light Grey 209 209 209
12 Light Brown 207 164 142
217-333-4747 (voice)
217-244-0802 (FAX)
isgs@isgs.uiuc.edu
These images are made available on-line as a service to interested data users. They provide suitable base map information for many mapping applications. The images are appropriate for use at a regional scale and are intended as a reference. The images are not appropriate for use at scales greater than 1:24,000, nor as a geodetic or engineering base.
Are there legal restrictions on access or use of the data?
- Access_Constraints: none
- Use_Constraints:
- Acknowledgment of the USGS, Illinois DNR, and the Illinois State Geological Survey (ISGS) would be appreciated in products derived from these data.
217-333-4747 (voice)
217-244-0802 (FAX)
isgs@isgs.uiuc.edu
The ISGS may distribute USGS DRGs, but they must be accompanied by the original metadata file and any changes that have been made to the data must be specifically indicated.The Illinois Department of Natural Resources (DNR) provides these geographic data "as is." DNR makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. DNR further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers of DNR, no warranty, expressed or implied, is made by DNR regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty.
In no event shall the DNR have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by DNR.
217-333-4747 (voice)
217-244-0802 (FAX)
isgs@isgs.uiuc.edu
Illinois Natural Resources Geospatial Data Clearinghouse
Generated by mp version 2.8.11 on Mon Jan 29 15:19:35 2007