The following is extracted from metadata of the United States Geological Survey for the original DLGs:
"Digital line graph (DLG) data are digital representations of cartographic information. DLGs of map features are converted to digital form from maps and related sources... All DLG data distributed by the USGS are DLG - Level 3 (DLG-3), which means the data contain a full range of attribute codes, have full topological structuring, and have passed certain quality-control checks."
The following is extracted from metadata of the United States Geological Survey for the original DLGs:
"DLGs depict information about geographic features on or near the surface of the Earth, terrain, and political and administrative units. These data were collected as part of the National Mapping Program."
This data set was compiled by Indiana University, Indiana Geological Survey, using data believed to be accurate; however, a degree of error is inherent in all data. This product is distributed "AS-IS" without warranties of any kind, either expressed or implied, including but not limited to warranties of suitability to a particular purpose or use. No attempt has been made in either the design or production of these data to define the limits or jurisdiction of any federal, state, or local government. These data are intended for use only at the published scale or smaller and are for reference purposes only. They are not to be construed as a legal document or survey instrument. A detailed on-the-ground survey and historical analysis of a single site may differ from these data.
COPYRIGHT 2003, THE TRUSTEES OF INDIANA UNIVERSITY, INDIANA GEOLOGICAL SURVEY, ALL RIGHTS RESERVED
The information on these media is proprietary to Indiana University, Indiana Geological Survey. Any copying, adaptation, distribution, public performance, or public display of this information without the express written consent of Indiana University, Indiana Geological Survey is discouraged.
CREDIT
It is requested that the Indiana Geological Survey be cited in any products generated from this data. The following source citation should be included: CONTOURS_24K_USGS_ADRIAN: Elevation Contours from 7.5-Minute Topographic Quadrangle Maps, Grouped into the 30' x 1° Adrian Quadrangle, Indiana, Michigan, and Ohio (United States Geological Survey, 1:24,000, Line Shapefile).
WARRANTY
Indiana University, Indiana Geological Survey warrants that the media on which this product is stored will be free from defect in materials and workmanship for ninety (90) days from the date of acquisition. If such a defect is found, return the media to Publication Sales, Indiana Geological Survey, 611 North Walnut Grove, Bloomington, Indiana 47405 2208, and it will be replaced free of charge.
LIMITATION OF WARRANTIES AND LIABILITY
Except for the expressed warranty above, the product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product users indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product.
NOTE: Some lines appear to have elevation values that are too small or too large for the range of elevations found within the quadrangle. Furthermore, elevation values of "0" (zero) or "-9999" are associated with boundaries, such as quadrangle boundaries, surface-mine boundries, and lake shores.
The following is extracted from metadata of the United States Geological Survey for the original DLGs:
"Topological requirements include: lines must begin and end at nodes, lines must connect to each other at nodes, lines do not extend through nodes, left and right areas are defined for each line element and are consistent throughout the file, and the lines representing the limits of the file (neatline) are free of gaps. The tests of logical consistency were performed by the USGS PROSYS program. The neatline was generated by connecting the four corners of the digital file, as established during initialization of the digital file. All data outside the enclosed region were ignored and all data crossing these geographically straight lines were clipped at the neatline. Data within a specified tolerance of the neatline were snapped to the neatline. Neatline straightening aligned the digitized edges of the digital data with the generated neatline, that is, with the longitude/latitude lines in geographic coordinates. All internal areas were tested for closure using PROSYS."
The following is extracted from metadata of the United States Geological Survey for the original DLGs:
"For Digital Revision Status = Not revised: Data completeness reflects the content of the source quadrangle. Features may have been eliminated or generalized on the source graphic, due to scale and legibility constraints. For Digital Revision Status = Limited Update: This file has undergone limited update digital revision. The file contains only: those features that are photoidentifiable on monoscopic source, supplemented with limited ancillary source, and those features, present on the original source quadrangle, that can not be reliably photoidentified but that are not considered particularly prone to change. For Digital Revision Status = Standard Update: This file has undergone standard update digital revision. The data completeness of this file meets NMD standards for feature content."
The following is extracted from metadata of the United States Geological Survey for the original DLGs: "For Digital Revision Status = Not revised"
The following is extracted from metadata of the United States Geological Survey for the original DLGs:
"For Hypsography, Hydrography, and Survey Control and Markers Only: For Digital Revision Status = Not revised:"
Individual quadrangle coverages were modified by adding blank major and minor pairs, as necessary, to make the same attribute structure in all 7.5-minute quadrangle areas within a 1:100,000 quadrangle area.
The following commands were used to move elevation values from the minor fields to new fields named ELEV, ELEV_TOT, and ELEV_NO. ELEV_TOT was later deleted. In cases where there were more than four major and minor codes, an iterative process was used. Any minor fields which had the code for a depression contour (611) were converted to "YES" values in a field named SINK.
Commands:
*/delete any preexisting fields in the cover.aat table
dropitem w_frankfort.aat elev sink elev_tot elev_no
*/add and define the fields elev,sink,elev_no, and elev_tot
additem w_frankfort.aat elev 6 6 i
additem w_frankfort.aat sink 3 3 c
additem w_frankfort.aat elev_no 2 2 i
additem w_frankfort.aat elev_tot 8 8 i
*/move the data from the appropriate minor pair to the new field
sel w_frankfort.aat
resel major1 = 22
calculate elev_tot = minor1
calculate elev_no = 1
asel
resel minor1 = 611
move 'YES' to sink
asel
resel major2 = 22
calculate elev_tot = minor2 + elev_tot
calculate elev_no = 1 + elev_no
asel
resel minor2 = 611
move 'YES' to sink
asel
resel major3 = 22
calculate elev_tot = minor3 + elev_tot
calculate elev_no = 1 + elev_no
asel
resel minor3 = 611
move 'YES' to sink
asel
resel major4 = 22
calculate elev_tot = minor4 + elev_tot
calculate elev_no = 1 + elev_no
asel
resel minor4 = 611
move 'YES' to sink
asel
*/ calculate the final elev value by dividing the sum of all elevations
*/ (elev_tot), by the number of elevations per line (elev_no)
resel elev_no > 0
calculate elev = elev_tot / elev_no
asel
A "clean-up macro was then run to drop the unnecessary fields.
dropitem muncie.aat muncie.aat major1 minor1 major2 minor2
dropitem muncie.aat muncie.aat major3 minor3 major4 minor4
dropitem muncie.aat muncie.aat elev_tot
After these commands were run, the ESRI coverage was converted to an ESRI shapefile using ESRI ArcGIS 8.3 ArcCatalog. Attribute fields specific to the coverage format were dropped from the shapefile.
The information on these media is proprietary to Indiana University, Indiana Geological Survey. Any copying, adaptation, distribution, public performance, or public display of this information without the express written consent of Indiana University, Indiana Geological Survey is discouraged.
CREDIT
It is requested that the Indiana Geological Survey be cited in any products generated from this data. The following source citation should be included: CONTOURS_24K_USGS_ADRIAN: Elevation Contours from 7.5-Minute Topographic Quadrangle Maps, Grouped into the 30' x 1° Adrian Quadrangle, Indiana, Michigan, and Ohio (United States Geological Survey, 1:24,000, Line Shapefile).
WARRANTY
Indiana University, Indiana Geological Survey warrants that the media on which this product is stored will be free from defect in materials and workmanship for ninety (90) days from the date of acquisition. If such a defect is found, return the media to Publication Sales, Indiana Geological Survey, 611 North Walnut Grove, Bloomington, Indiana 47405 2208, and it will be replaced free of charge.
LIMITATION OF WARRANTIES AND LIABILITY
Except for the expressed warranty above, the product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product users indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product.