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Geographic Coordinate DataBaseWhat Where HowFred WheelerCadastral SurveyorCentral Valley Chapter CLSAApril 25, 2012

Bureau of Land ManagementGCDB1Geographic Coordinate Data Base

What Makes Up a GCDB?Why is a GCDB needed?

I will discuss what the GCDB is for and why it is needed will become apparent.2What is the GCDB?A seamless network of Survey and Land Description records.Provides increased GIS accuracies for the PLSS corners.Provides basis for integration of additional Survey and Land records for defining other parcels Base for the CadNSDI - Land Information System 3

Public Land Surveys System Land and Mineral Records Resource Data

Data CollectionGMM and PCCS Flat Files NAD 1927Ground based measurements are used in both systems. PLSS Coordinate Collection System and GCDB Measurement Management5Data CollectionNILS DataBase NAD 1983

Ground based measurements are used in both systems.6Flat files or DatabaseFederal Records

State/Local

Private Records

Other

GCDB 7Survey Records are input from a variety of sources. Including Official government Surveys and Land Description records. In addition, any local, state and private records are included as well.Data CollectionGCDB data collection has created ASCII flat files using BLM developed software.PCCSGMMGeoCommunicator is the public website for publication of the BLM and FS Land Records.(www.geocommunicator.gov) Mention NAD 28 vs NAD 83 data.8Uses for the GCDB dataIt can be used to improve the positional accuracies of GIS dataSurveyors and land managers can use coordinates to search for property corner monumentsLand managers can use data to plan for land uses.

Where to get the GCDB.GMM and PCCS datahttp://www.blm.gov/ca/st/en/prog/cadastral/gcdbpage.htmlftp://ftp.blm.gov/pub/CA/gcdbSee the gcdbread.txt & caluser.doc for infoGeoCommunicatorhttp://www.geocommunicator.gov10GeoCommunicator

GeoCommunicator the Data Publication Website

Based in ArcGis technology from ESRIDownloadable DataInteractive MapsMap ServicesWeb Services Tools12GeoCommunicator the Data Publication Website

Search by township, lat and long, place names, BLM case records, etc.PDF exports of maps. Links to BLM MTPs, and BLM and FS reports 13Land and Minerals Use

Derive and Find Land Descriptions tools.14Land Survey Information System

15Land Survey Information System

Survey Exporter tools.16Need more Information?Contact the GCDB staff at:Bureau of Land ManagementBranch of Geographic Services, GCDB Section2800 Cottage WaySacramento, CA 95825Or Phone:(916) 978 - 4340