Identification Information

Title Railroads for Socorro County, New Mexico, 2006se TIGER

Date 2008-01-23

Date Type Publication

Cited Responsible Party

Organization Name Earth Data Analysis Center

Role identify

Presentation Form vector digital data

Abstract The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage for a single TIGER/Line file is a county or statistical equivalent entity, with the coverage area based on the latest available governmental unit boundaries. The Census TIGER database represents a seamless national file with no overlaps or gaps between parts. However, each county-based TIGER/Line file is designed to stand alone as an independent data set or the files can be combined to cover the whole Nation. The 2006 Second Edition TIGER/Line files consist of line segments representing physical features and governmental and statistical boundaries. This shapefile represents railroad layer stored in the 2006 TIGER Second Edition dataset for Socorro County, NM.

Purpose In order for others to use the information in the Census TIGER database in a geographic information system (GIS) or for other geographic applications, the Census Bureau releases to the public extracts of the database in the form of TIGER/Line files. This shapefile represents railroad layer stored in the 2006 TIGER Second Edition dataset for Socorro County, NM.

Supplemental Information The TIGER/Line data are not in a mapping projection even though most of the features were scanned directly from source maps that were in a projection. To find out more about TIGER/Line files and other Census TIGER database derived data sets visit http://www.census.gov/geo/www/tiger. This shapefile was created by using the conversion tool TGR2SHP version 7.0. The shapefile was projection defined using ArcCatalog v 9.2.

Status Complete

Point of Contact

Individual Name

Organization Name Earth Data Analysis Center

Position Name RGIS Clearinghouse Manager

Role Point of contact

Voice (505) 277-3622

Facsimile (505) 277-3614

Address

Delivery Point MSC01 1110
Delivery Point 1 University of New Mexico
Delivery Point University of New Mexico
City Albuquerque
Administrative Area NM
Postal Code 87131-0001
Country United States

Electronic Mail Address clearinghouse@edac.unm.edu

Maintenance and Update Frequency As needed

Descriptive Keywords TIGER Data, Census Data, 2006 TIGER Second Edition, Transportation, Railroads

Access Constraints None

Use Constraints Acknowledgment of the U.S. Census Bureau would be appreciated for products derived from these files. TIGER, TIGER/Line, and Census TIGER are registered trademarks of the U.S. Census Bureau. ZCTA is a trademark of the U.S. Census Bureau. The boundary information in the TIGER/Line files are for statistical data collection and tabulation purposes only; their depiction and designation for statistical purposes does not constitute a determination of jurisdictional authority or rights of ownership or entitlement and are they are not legal land descriptions. The horizontal spatial accuracy information present in these files is provided for the purposes of statistical analysis and census operations only. The TIGER/Line files may not be suitable for high-precision measurement applications such as engineering problems, property transfers, or other uses that might require highly accurate measurements of the earth's surface. Coordinates in the TIGER/Line files have six implied decimal places, but the positional accuracy of these coordinates is not as great as the six decimal places suggest. No warranty, expressed or implied is made with regard to the accuracy of these data, and no liability is assumed by the U.S. Government in general or the U.S. Census Bureau or Resource Geographic Information system Program (RGIS) in specific as to the spatial or attribute accuracy of the data. The act of distribution shall not constitute any such warranty and no responsibility is assumed by the U.S. Government or RGIS in the use of these files. The boundary information in the TIGER/Line files are for statistical data collection and tabulation purposes only; their depiction and designation for statistical purposes does not constitute a determination of jurisdictional authority or rights of ownership or entitlement and they are not legal land descriptions.

Language English

Topic Category transportation

Extent

Geographic Bounding Box

West Bound -107.016244
East Bound -106.416956
North Bound 34.541634
South Bound 33.477567

Temporal Extent

Beginning Position 2006-07-01
Ending Position 2006-12-31

Data Quality Information

Attribute Accuracy Report

Report Accurate against Federal Information Processing Standards (FIPS), FIPS Publication 6-4, and FIPS-55 at the 100% level for the codes and base names. The remaining attribute information has been examined but has not been fully tested for accuracy.

Quantitative Attribute Accuracy Assessment

Attribute Accuracy Value
Attribute Accuracy Explanation

Horizontal Positional Accuracy Report

Report The Census Bureau uses Global Positioning System (GPS) coordinates at road centerline intersections to evaluate the horizontal spatial accuracy of source files that may be used to realign road features in the TIGER database and test the horizontal spatial accuracy of the road features in the TIGER/Line files. The test compares a survey-grade GPS coordinate to its associated road centerline intersection in the TIGER file. The test is based upon an independent collection of GPS coordinates for a random sample of road intersections from a centerline file that meet certain criteria. The points are referred to as the sample points and are gathered through a private contractor working for the Census Bureau. Since the collection method uses survey-quality GPS-based field techniques, the resulting control points are considered "ground truth" against which the TIGER road centerline intersection coordinates are compared. The distances between the coordinates are calculated and the Census Bureau determines the Circular Error 95% (CE95). That is, the accuracy of the file in meters with 95% confidence. The CE95 can be calculated from the mean and standard deviation by using the formula: mean of differences plus (2.65 times the standard deviation). CE95 results reported for each file tested are determined using a spreadsheet with embedded statistical formula. The use and applicability of the spreadsheet and its embedded formula have been verified by Census Bureau statisticians. The basis of the calculation is the use of the root mean square error (RSME). This is the method as stated in the U.S. Government's Federal Geographic Data Committee Standard FGDC-STD-007.3-1998, Geospatial Positioning Accuracy Standards. Part 3: National Standard for Spatial Data Accuracy. The results of using this measure of accuracy are in compliance with Federal Spatial Data requirements. In terms of the Census Bureau application, the dataset coordinate values are those taken from the centerline file and the coordinate values from an independent source of higher accuracy are those acquired through the Census Bureau's contractor. Please note that the horizontal spatial accuracy, where reported, refers only to the realigned road features identified as matched to the positionally accurate source file with that accuracy. It is not the spatial accuracy of the TIGER/Line file as a whole.

Quantitative Horizontal Positional Accuracy Assessment

Horizontal Positional Accuracy Value
Horizontal Positional Accuracy Explanation

Logical Consistency Report The feature network of lines (as represented by Record Types 1 and 2) is complete for census purposes. Spatial objects in TIGER/Line belong to the "Geometry and Topology" (GT) class of objects in the "Spatial Data Transfer Standard" (SDTS) FIPS Publication 173 and are topologically valid. Node/geometry and topology GT-polygon/chain relationships are collected or generated to satisfy topological edit requirements. These requirements include: (1) Complete chains must begin and end at nodes. (2) Complete chains must connect to each other at nodes. (3) Complete chains do not extend through nodes. (4) Left and right GT-polygons are defined for each complete chain element and are consistent throughout the extract process. (5) The chains representing the limits of the files are free of gaps. The Census Bureau performed automated tests to ensure logical consistency and limits of files. All polygons are tested for closure. The Census Bureau uses its internally developed Geographic Update System to enhance and modify spatial and attribute data in the Census TIGER database. Standard geographic codes, such as FIPS codes for states, counties, municipalities, county subdivisions, places, American Indian/Alaska Native/Native Hawaiian areas, and congressional districts are used when encoding spatial entities. The Census Bureau performed spatial data tests for logical consistency of the codes during the compilation of the original Census TIGER database files. Most of the codes for all geographic entities except states, counties, and congressional districts were provided to the Census Bureau by the USGS, the agency responsible for maintaining FIPS 55. Feature attribute information has been examined but has not been fully tested for consistency.

Completeness Report Data completeness of the TIGER/Line files reflects the contents of the Census TIGER database at the time the TIGER/Line files (2006 Second Edition version) were created.

Lineage

Source Information

Source Citation

Source Scale Denominator

Type of Source Media On line

Source Time Period of Content

Beginning Position 2006-07-01
Ending Position 2006-12-31
Source Currentness Reference publication date

Source Citation Abbreviation TIGER_06SE

Source Contribution Selected geographic and cartographic information (line segments) from the Census TIGER database.

Process Step

Process Description In order for others to use the information in the Census TIGER database in a GIS or for other geographic applications, the Census Bureau releases periodic extracts of selected information from the Census TIGER database, organized as topologically consistent networks. Software (TIGER DB routines) written by the Geography Division allows for efficient access to Census TIGER system data. TIGER/Line files are extracted from the Census TIGER database by county or statistical equivalent area. Census TIGER data for a given county or statistical equivalent area is then distributed among 19 fixed length record ASCII files, each one containing attributes for either line, polygon, or landmark geographic data types. The Census Bureau has released various versions of the TIGER/Line files since 1988, with each version having more updates (feature and feature names, address ranges and ZIP Codes, coordinate updates, revised field definitions, etc.) than the previous version. For an understanding of the CFCC Codes see the Census Bureau's TIGER report: http://www.census.gov/geo/www/tiger/tiger2006se/TGR06SE.pdf
Process Date 2006-12-31
Process Time
Process Contact

Process Step

Process Description TGR2SHP was run on the Socorro County TIGER 2006 Second Edition to pull out the layers stored in the file. This shapefile represents railroad layer stored in the 2006 TIGER Second Edition dataset for Socorro County, NM. For additional information on the software, please refer to the following reports: http://tnatlas.geog.utk.edu/freeware/Manual622.pdf http://tnatlas.geog.utk.edu/freeware/TGR2SHPWhitepaper.pdf

Source Used Citation Abbreviation TIGER_06SE

Process Date 2007-05-16

Process Time

Process Contact

Individual Name

Organization Name Earth Data Analysis Center

Position Name RGIS Clearinghouse Manager

Role Point of contact

Voice (505) 277-3622

Facsimile (505) 277-3614

Address

Delivery Point MSC01 1110
Delivery Point 1 University of New Mexico
Delivery Point University of New Mexico
City Albuquerque
Administrative Area NM
Postal Code 87131-0001
Country United States

Electronic Mail Address clearinghouse@edac.unm.edu

Railroads for Socorro County, New Mexico, 2006se TIGER

Metadata from the RGIS Metadata Repository

Identification Information

Distribution Information

Spatial Reference Information

Data Quality Information

Metadata Reference Information