Control Point Inventory Working Together In Minnesota To Share Data About Public Land Survey Corners
Main Points • The Importance of the PLS in a Cadastral Database • David Claypool • CPI - What MN is doing to locate PLSS corners • Dave Zenk • National Cadastral Efforts • David Claypool
The Importance of the PLS in a Cadastral Database David Claypool
Why Use a Control System? • All geospatial data must be referenced to a physical location • Preferably referenced to physical locations that are relative to one another and have common relationships • Field location • PLS monumentation • Scale • Projections • Various coordinate systems
Why use the Public Land Survey System (PLSS) for Control? • It is a physical system that is in place and is government sponsored • In Minnesota, the State and Counties are responsible for the system • Many counties use the County Coordinate System with the PLS as the basis for surveying and mapping • State and Federal geodetic control can tie into PLS corners • It is the basis of • All land descriptions • All land surveys (plats, utility location, road construction control, parcel surveys) • GIS mapping • Cadastral mapping (tax parcels) • Cadastral control
What is a Cadastre/Cadaster? • Cadastre/Cadaster • An official register of the quantity, value, and ownership of real estate, used in apportioning taxes1 • A public record, survey, or map of the value, extent, and ownership of land as a basis of taxation2 1. Definitions of Surveying and Associated Terms 2. The American Heritage Dictionary, Second College Edition
What is a Cadastral Map? • Cadastral Map • A map showing the boundaries of subdivisions of land, usually with the bearings and lengths thereof and the areas of individual tracts, for purposes of describing and recording ownership. A cadastral map may also show culture, drainage, and other features relating to the value and use of land.1 1. Definitions of Surveying and Associated Terms
What is Cadastral Control? • Cadastral Control (USPLS) • Lines established and marked on the ground by suitable monuments, which are used as starting and closing points in surveys of the public domain of the United States. The primary control of the public land surveys of the United States consists of base lines, standard parallels (correction lines), principal meridians, and guide meridians.1 1. Definitions of Surveying and Associated Terms
A Parcel Based GIS Basemap • A GIS basemap that is parcel based is the most effective way to handle spatial data • Land related activities such as subdivision plats, lot splits, and other locational measurements are more spatially correct as a result of utilizing a PLS parcel based GIS
Southwest Quarter Corner South Quarter Corner Section 22, Township 29N, Range 22W
What MN is doing to locate PLSS Corners – the CPI • MN/DOT Geodetics Unit provides high accuracy control points. • MN/DOT and others use these points to locate PLSS and other points of interest. • Serve this information to the public via a database that is called the Control Point Inventory or CPI.
Control Point Inventory – CPI • CPI includes Geodetic, PLS, and Local control points database subsets. • See entity-relationship diagram. • Built by multiple agency group. • LMIC, DNR, MN/DOT, US Forest Service • To support multiple needs. • Right-of-way, land use, aerial photos • To coordinate with other efforts. • GCDB, NILS, NSDI and others.
Relationship to GCDB CPI Database GCDB Database Share Common Key Fields
Where are we now? • LMIC & DNR have digitized section corners for entire state at 1:24,000 • DNR has supplied higher accuracy data for about 6,000 section corners • County Surveyors will provide best accuracy and the most complete data • Douglas County Pilot
Where are we headed? • Web-based access to database reports beginning 1-1-01 • Batch Input Process in place • Training by MN/DOT by 3-1-01 • http://rocky.dot.state.mn.us/cpi
National Cadastral Efforts David Claypool
Government Cadastral Activities • FGDC – Federal Geographic Data Committee • www.fgdc.gov • NSDI – National Spatial Data Infrastructure • www.fgdc.gov/nsdi/nsdi.html • GCDB – Geographic Coordinate Database • www.blm.gov/nhp/what/lands/title/cadastre.htm • NILS – National Integrated Land System • www.blm.gov/nils • GeoCommunicator • www.blm.gov/nils/geo-comm/index.htm • BLM – Bureau of Land Management • www.blm.gov • Fairview Industries – Nancy Von Meyer, Links to Cadastral Subcommittee etc www.fairview-industries.com
FGDC Cadastral Subcommittee • The Cadastral Subcommittee is made up of representatives of various states and organizations • It meets under the auspices of BLM and has many BLM representatives available • As a subcommittee of FGDC, it has submitted information for cadastral and other standards which are in effect
Vision • The vision is to establish a comprehensive geographic coordinate database • This collective dataset, which will cover large areas, will be electronically available to everyone
Activities • For the past few years, the subcommittee has worked with western states • Some western states are involved in parcel mapping • In response to the work done by the subcommittee and BLM, some western governors are working together to lobby the federal government to make funds available for these cadastral mapping products
Activities • Some states and counties have already received funding for projects under the auspices of the federal committees • In November of 2000, the subcommittee met to work with eastern states’ issues
Eastern States • The subcommittee intends to have ongoing activities which will be based on the successes of the western states • Funds have been requested to hold forums in various regions of the eastern states • The forums will plan for methods of establishing core data sets and minimal planning for other cadastral issues • The forums will also present an opportunity to examine necessary business functions in the various regions
Eastern States • The subcommittee will ask for pass through dollars from BLM to the states and counties for the purpose of working with their cadastral systems • The subcommittee is presenting requests for funds which reflect business needs that can be supported with cadastral information • Some cadastral business needs that are already being discussed are mitigation, fire and fuel • One of the major needs for a good cadastral base is to identify the area of wild lands/urban interface which creates areas of potential fire danger
FGDC • The Federal Geographic Data Committee coordinates the development of the National Spatial Data Infrastructure (NSDI). The NSDI encompasses policies, standards, and procedures for organizations to cooperatively produce and share geographic data. The 17 federal agencies that make up the FGDC are developing the NSDI in cooperation with organizations from state, local and tribal governments, the academic community, and the private sector.
NSDI • Consistent means to share geographic data among all users could produce significant savings for data collection and use and enhance decision making. Executive Order 12906 calls for the establishment of the National Spatial Data Infrastructure defined as the technologies, policies, and people necessary to promote sharing of geospatial data throughout all levels of government, the private and non-profit sectors, and the academic community.
GCDB • The Bureau of Land Management's (BLM) Geographic Coordinate Data Base (GCDB) is a collection of geographic information representing the Public Land Survey System (PLSS) of the United States. The GCDB grid is computed from BLM survey records (official plats and field notes), local survey records, and geodetic control information.
GCDB • BLM collects the GCDB data on a township basis. The survey boundaries are delineated by computing the geographic positions of township, section, aliquot part, government lot, and special survey corners. Next, official land descriptions are assigned to each land unit in the grid. The records are then reformatted so Geographic Information System (GIS) software can be used to view the PLSS information spatially.
NILS • The National Integrated Land System (NILS) is a joint project between the BLM and the USDA Forest Service in partnership with the states, counties, and private industry to provide business solutions for the management of cadastral records and land parcel information in a Geographic Information System (GIS) environment. The goal of NILS is to provide a process to collect, maintain, and store parcel-based land and survey information that meets the common, shared business needs of land title and land resource management.
NILS • The NILS concept would provide the user with tools to manage land records and cadastral data in a "Field-to-Fabric" manner. The user would be able to use field survey measurement data directly from the survey measuring equipment, manipulate this data into lines and points, and create legal land and parcel descriptions to be used in mapping and land record maintenance.
NILS • This concept implies the development of a common data model that unifies the worlds of surveying and GIS. This unification concept is fundamental for land records managers and maintainers of cadastral mapping databases to improve the accuracy and quality of the data, to create standard land descriptions and cadastral data that can be used by anyone.
GeoCommunicator • The GeoCommunicator is a proactive Internet subscription (no fee) Web site for sharing information about data and activities of interest to land managers. Map navigation and content filters will allow users to discover information that meets their needs such as available parcel data, planned surveys, and potential cost-sharing partners. GeoCommunicator facilitates data sharing and collaborative efforts among land managers.