adce21c5-7245-4316-9ff2-4a7ade85eaca en Mike Sharp Oklahoma Office of Geographic Information L&RPO GCDB Lead (303) 236-0951 (303) 236-6691 Building 40, Denver Federal Center WO - 330D (DFC) P.O. Box 25047 Denver Colorado 80225-0047 USA mike.sharp@conservation.ok.gov For information about the data content, please contact the BLM State Office, GCDB Manager or GCDB Contact at: http://www.blm.gov/gcdb/gcdbsites/index.html For information directly relating to metadata, please contact Regina LeFort at regina.lefort@blm.gov 2020-09-27T20:50:07 ISO 19115:2003/19139 1.0 17614091 17614091 OK-BLM QQSections and Lots 2020-09-27 Bureau of Land Management and the Oklahoma Office of Geograpic Information THE BLM Second Division DATASET FOR OKLAHOMA HAS BEEN MODIFIED TO INCLUDE ONLY PLSS Second Division (QQ Sections and Lots) DATA WITHIN THE CURRENT BOUNDARY OF OKLAHOMA. This layer is based on Geographic Coordinate Data Base (GCDB) coordinate data. The locations of Public Land Survey System (PLSS) corners, as represented in geographic coordinate pairs, were derived from a variety of source documents, which include U.S. General Land Office and BLM survey plats/notes, as well as survey data obtained from other U.S. Government agencies, private sector survey firms, and local governments. The attributes assigned to PLSS polygons were taken from the BLM's Legal Land Description (LLD) data set, contained within the Legacy Rehost for the year 2000 (LR2000) automated records system. The coordinate data was produced by using control stations of known location, with varying degrees of accuracy, from various sources which include but are not limited to; U.S. Geological Survey (USGS) topological quadrangles and other sources, National Geodetic Survey (NGS) and US Coast & Geodetic Survey (USC&GS) Cooperative Base Network (CBN) control, Federal Base Network control (FBN), and Continuous Operating Reference Stations (CORS), and Global Positioning System (GPS) data, which is then analyzed and adjusted in concert with official survey data for any given geographic area. The Land Survey Information System Data Base (LSIS) data is a useful representation of the geometry and topology of parcels contained within the PLSS, but its application is intended for mapping purposes only. The GCDB data served from LSIS is not a substitute for a legal land survey. The GCDB Data was created to provide the BLM and its public with a set of geographic foundation data that accurately portrays the locations of PLSS corners. The GCDB data is based on the best and most current survey records available and uses known geographic positions of control stations within the PLSS network. This data is a key component of the Land Survey Information System (LSIS) framework upon which parcel boundary information will be assembled. Mike Sharp Oklahoma Office of Geographic Information L&RPO GCDB Lead (303) 236-0951 (303) 236-6691 Building 40, Denver Federal Center Mail Stop: WO - 330D (DFC) P.O. Box 25047 Denver Colorado 80225-0047 USA mike.sharp@conservation.ok.gov For information about the data content, please contact the BLM State Office, GCDB Manager or GCDB Contact at: http://www.blm.gov/gcdb/gcdbsites/index.html For information directly relating to metadata, please contact Regina LeFort at regina.lefort@blm.gov Cadastral Land Grids BLM-Theme Township LSI Range BLM National Spatial Data Infrastructure General Land Office GLO NSDI PLSS LSIS Cadastral Land Survey Information LIS Bureau of Land Management Land Information System Geographic Coordinate Data Base GCDB Land Survey Information System Public Land Survey System Second Division Quarter Quarter Section Government Lots None Oklahoma BLM-State Contiguous US Oklahoma None Downloadable Data access constraints: None use constraints: The geographic coordinates and their associated products are NOT legal land survey records. The coordinates can NOT be used as a substitute for a legal land survey. They can be used for record keeping, mapping, graphics and planning purposes only. No warranty is made by the Bureau of Land Management for use of the data for purposes not intended by BLM. Although these data have been processed successfully on a computer system at the U.S Bureau of Land Management, no warranty, expressed or implied, is made by the BLM regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. en structure Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 1; ESRI ArcCatalog 9.0.0.535 -103.05 -94.40 33.50 37.0009 ground condition 1849-03-03T00:00:00 ARCE unknown Mike Sharp Oklahoma Office of Geographic Information L&RPO GCDB Lead (303) 236-0951 (303) 236-6691 Building 40, Denver Federal Center WO-330D (DFC) P. O. Box 25047 Denver Colorado 80225-0047 USA mike.sharp@conservation.ok.gov For information about the data content, please contact the BLM State Office, GCDB Manager or GCDB Contact at: http://www.blm.gov/gcdb/gcdbsites/index.html For information directly relating to metadata, please contact Regina LeFort at regina.lefort@blm.gov No fees are required for downloading the data that is on-line. 5 http://okmaps.org/geoserver/wms OGC:WMS-1.1.1-http-get-map ogi:ok-blm_plssseconddivision_1928_4326 BLM QQSections and Lots The data set is topologically structured with nodes at all intersections. Labels representing the legal land description are assigned to each land unit. Accuracy of the individual points contained within the GCDB layers of LSIS that were determined using GMM software were adjusted using both compass rule and a least squares analysis, which examines the geometry of PLSS parcels in relation to the coordinate values of known locations for control points within the PLSS grid. Each individual point carries a reliablility factor indicating the error ellipse in both northing and easting which is reported after the least squares analysis is completed. Accuracy of the individual points contained within the GCDB layers of LSIS that were determined using PCCS software were adjusted using a succession of compass rule adjustments between the control points followed by a least squares analysis, which examines the geometry of PLSS parcels in relation to the coordinate values of known locations for control points within the PLSS grid. Each individual point carries positional reliability factors for the average of the misclosures in the data set and the maximum misclosure in the data set. Data was checked for attribute accuracy by the GCDB personnel in each of the respective BLM State Offices. GIS coverages are edgematched with adjoining township data sets to insure a seamless PLSS grid is created. If topological errors exist, editing of arc and node data, as well as parcel labels, is performed using either GMM or ArcInfo Interface (AII). (PCCS townships can only be edited using AII). Final edits are entered into input files and the process is repeated until all errors are corrected and a successful GIS coverage is created. This data has been created in either the GMM or PCCS format. The following process steps refer to data in PCCS format. With PCCS, survey data abstracted from survey plats and control stations extracted from control data base are manually entered into the PCCS processing software. A succession of compass rule adjustments is performed on the lines to adjust them to the control points, followed by a least squares analysis. The resulting coordinates are accompanied by indications of positional reliability; the average of misclosures in the data set and the maximum misclosure in the data set. PCCS lists all coordinates produced by the compass rule and least squares adjustments with conectivity codes between points and compiles them into a single file for development of GIS files. With PCCS, section subdivision is performed to achieve land unit detail to at least the forty acre parcel level. Topologically correct GIS coverages are modified to use FGDC compliant naming conventions and then loaded into the LSIS database. These layers can then be downloaded as shapefiles through the LSIS website. This data has been created in either the GMM or PCCS format. The following process steps refer to data in GMM format. With GMM survey data, abstracted from survey plats, and control stations extracted from the control database, are manually entered with weighting factors into GMM software. Compass rule and least squares adjustments are performed using weighting factors assigned to both control stations and survey line data, based on methodologies and vintage of survey. With GMM, section subdivision is performed to achieve land unit detail to at least the forty acre parcel level. Instructions for calculating non-regular and minor subdivisions are persistently stored during collection and rerun after every new adjustment in order to achieve the detail necessary to delineate all lines required for depicting federal rights, interestes, restrictions, and encumberances. Coincident lines and lines identified as non-boundary lines are removed from the data set used for final land unit constructions. Line intersections are computed and given unique identifiers and land units are constructed. GMM lists all coordinates produced by the compass rule and least squares adjustments and subdivision, with conectivity codes between points and compiles them into a single file for development of Geographic Information Systems (GIS) output. Coordinates of control stations are entered into a control data base with associated reliabilities. Verified coordinate, line and label files are converted to GIS coverages using the topology check application. All errors in topology are flagged for editing and correction. Compile listings of known locations of PLSS corners. Compile survey input data from current BLM official measurements, supplemented in some locations with USFS and private survey records. Metadata imported. GCDB data conversion software verifies correctness of GCDB file formats and content. Survey control data from the official control station sheets (CBN, FBN, CORS). Official Control Station Sheets 2000-01-01 National Geodetic Survey National Geodetic Survey Digitized control data from standard topological quadrangle sheets. USGS standard topological quadrangles 1931-01-01 U.S Geological Survey U.S. Geological Survey Survey and control data from the Cartographic Feature File (CFF) data set. Automated Lands Project (ALP) 1998-06-01 U.S. Forest Service U.S. Forest Service Survey data in the form of official (microfilm, CD, other) survey and BLM, abstracted into a vector digital format. Land Survey Information System (LSIS) 2004-10-29 Bureau of Land Management Oklahoma Office of Geographic Information