Geographic Coordinate Data Base Overview

Transcription

1 Geographic Coordinate Data Base Overview August 28, 2013

2 Discussion Points Overview, Public Land Survey System (PLSS) Geographic Coordinate Data Base (GCDB) GCDB Data Development GCDB Improvement Processes The work that has been done to improve control points Reliability Analysis Field Data Collection Existence of multiple land grids for the same area. IHS Confidential. For internal use only 2

3 PLSS Overview U.S. Land Ownership And Rights Are Tied To Historical Acquisitions Made Between 1783 through 1917 Public Land Survey System States Public Land Survey System Public Land Survey System Township, Range, Section Enacted into law by the Land Ordinance of 1785 Required surveying over 1.8 billion acres of land acquired through; Louisiana Purchase, Oregon Compromise, the Mexican Cession Other acquisition actions. There are about 2.6 million section corners throughout the United States the BLM is the Federal Government's official survey record keeper Over 200 years' worth of cadastral survey records and plats compiled IHS Confidential. For internal use only 3

4 United States Land Overview Land Ownership & Management Federal Government The Bureau of Land Management (BLM) Represent nearly 700 million acres of mineral estate. Acreage includes areas where BLM or other federal agencies manage the surface Includes areas where the surface is privately owned, but the minerals were reserved unto the US Premier refers to this category as Federal lands. Oil and gas leasing is conducted by oral auction based on schedules established by the Bureau of Land Management The total area of the US is approximately 2.3 billion acres GCDB Coverage Include Map of Current GCDB Coverage IHS Confidential. For internal use only 4

5 Development of the GCDB Geographic Coordinate Data Base: Framework for the BLM s Land Information System Contains latitude and longitude coordinate values for corner positions and monuments recorded in the PLSS Portrays the PLSS at a more detailed level than most other digital sources Subdivision of sections to 40 acres (some lower) Contains coordinates for non-rectangular surveys Mineral Surveys Homestead Entry Surveys Adjustment Lots Tracts Riparian Boundaries Etc 5 IHS Confidential. For internal use only 5

6 Initial Collection Geographic Coordinate Data Base Developed to capture the most dependable coordinates available for the U.S. Public Land Survey System (PLSS) corners To satisfy the need automated land records mapping. (Ownership/Use/Restrictions) The geographic coordinates and their by-products were generated from either PCCS or GMM Software Source documents: Survey Plats & Notes State, County and Private Survey Records Digitized Coordinates (USGS etc ) Field Observations and Survey Coordinates Graphic representations using these values depict the most probable township configuration and may change as a result of such updates. The geographic coordinates and their associated products have NO legal significance. These coordinates cannot be used as a substitute for a legal boundary survey. They can be used for recordkeeping, mapping, graphics and planning purposes only. No warranty is made by the Bureau of Land Management. IHS Confidential. For internal use only 6

7 Development of the Geographic Coordinate Data Base (GCDB) Survey records include cadastral survey plats and field notes of observations, measurements, and monuments, either in paper form or microfiche (35mm aperture cards). Reference Information consists of microfilm images of manual records (status plats, historical indices, tract books, GLO plats, miscellaneous document index, and index to mineral location and validity contest) as they existed at the time of automation. IHS Confidential. For internal use only 7

8 Control Point Reliability Reliability values are computed using GMM/PCCS software tools Each coordinate is assigned a reliability factor indicating the error ellipse in feet, in both northing and easting General error estimate values are as follows: Code Method Error Estimate 1 First Order Survey 1 foot or less 2 Second and Third Order Surveys 3 feet or less 3 Photogrammetric Tie Point 10 feet or less 4 Digitized 7.5 Minute Quad Sheets USGS Solid Lines 40 feet or less 5 Digitized 15 Minute Quad Sheets 100 feet or less 6 Other > 100 feet IHS Confidential. For internal use only 8

9 Era Of Survey 1850 until about 1909, manual measurement, steel chains, stadia rods, poor monument types 1910 and 1972, better instruments and measurement techniques, brass cap era Post 1972, electronic measurements, durable monuments IHS Confidential. For internal use only 9

10 GCDB Improvement Program IHS Confidential. For internal use only 10

11 GCDB Enhancement/Project Purpose Project Owner: Bureau of Land Management Cadastral Survey Group Enhance the positional accuracy of initial collection PLSS/GCDB Enhance the GIS depiction of boundaries Automate legacy survey records Automate plat mapping (owernship/use) Improve access to title record information for; Land Ownership Land Use Land Access Land Use Authorizations Land Use Restrictions Facilitate data sharing and publication standards Facilitate electronic data access and distribution IHS Confidential. For internal use only 11

12 Corner Record Research Chain of history to original corner Geographic coordinates Local control Historic use Established by proportion Local coordinates IHS Confidential. For internal use only 12

13 Corner Collection Data Enhancement /Coordinate Control Database Required to collect up to 6600 Points Multiple States/Multiple Contractors Must use technology to maximize efficiency COTS (CartoPac/ArcGIS Server) software to support coordinate collection, processing and project tracking. IHS Confidential. For internal use only 13

14 Corner Recovery and Measurement of Coordinate Positions State Corner Collected Arizona 1562 California 548 Colorado 1160 Idaho 341 Montana 999 New Mexico 1226 Oregon 120 Wyoming 631 Total 6587 Collection Twp. Target Corner Collected Corner Adjustment Block California Numbers IHS Confidential. For internal use only 14

15 Field Collection Map Service IHS Confidential. For internal use only 15

16 GCDB Enhancement Statistics, WY Survey coordinate collection to enhance the Geographic Coordinate Database Corners Collected: 631 Target Corners Searched for but Not Found: 21 (alternate corners selected & found). Corners Not Accessed: 3 (access denied by owner, no access via locked gates, etc.) Average Distance Moved (ft): Average Predicted PP Horiz Accuracy (ft): Average Predicted PP Vert Accuracy (ft): Phase I: 422 Points Phase II: 209 Points IHS Confidential. For internal use only 16

17 Collection Summary IHS Confidential. For internal use only 17

18 Cadastral Survey Review GCDB & USGS Corner Positions 18 IHS Confidential. For internal use only 18

19 Discussion Bob Johnson Premier Geo W 64 th Avenue Arvada, CO FAX bob.johnson@premiergeospatial.com Bruce Smith IHS Energy 15 Inverness Way, D205 Englewood, CO bruce.smith@ihsenergy.com IHS Confidential. For internal use only 19