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Supporting an Accessible Geodetic Control Network for California Presented by: The California GIS Council's Geodetic Control Work Group (CGWG) A Growing Concern for the Geospatial, Land Surveying and Mapping Communities
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Presentation Topics 1) Introduction of the GCWG. 2) Importance of a common reference frame. 3) Why GIS data needs Geodetic Control. 4) Geodetic control resources in California. 5) What's Next?
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Geodetic Control Work Group Formation History and Information The California GIS Council authorized formation of the Geodetic Control Work Group in November 2009. The work group was assembled in March 2010 & chaired by Marti Ikehara, retired NGS Advisor to California. A charter and work plan were approved by the CA GIS Council in April, 2011. Bi-monthly or Monthly teleconferences and meetings. Outreach subcommittee to give presentations. The CA GCWG operates independently of other groups.
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CA Geodetic Control Work Group GCWC – who are we? Chartered by CA GIS Council in April, 2011 GCWG Sub-committees o Strategic Plan Subgroup o Data Standards Subgroup o Outreach / Communication Plan Current Chair, Scott Martin – Caltrans John Canas - CSRCLandon Blake – O’Dell Engineering, Inc. Tom Dougherty - S.C.V.W.DJustin Height - Penfield & Smith, ACEC, CA Ryan Hunsicker – Sn.Bdo.Cnty, CLSABruce Joffe - GIS Consultants Ric Moore – BPELSGNeil King – PhotoScience, Inc. ACEC-CA Mark Turner- CaltransMichael McGee - McGee Surveying, CLSA Kristin N. Hart - Padre Associates, Inc.Reg Parks - Santa Rosa Junior College, PVTS
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GCWG Milestones for Success Charter documents (√), Strategic Plan, Work Plan (√), approved by CA GIS Council. Outreach Plan to elicit feedback Geodetic control data sources & standards for metadata. Recommendations for standards, stewardship, and funding for geodetic theme and infrastructure. Strategic Plan and Business Plan for adoption by the CGC. Policy and technical statements for utilization and alignment of the GC theme by other GIS themes.
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Presentation Topics 1) Introduction of the GCWG. 2) Importance of a common reference frame. 3) Why GIS data needs Geodetic Control. 4) Geodetic control resources in California. 5) What's Next?
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(Reprioritized to #1 in 2014 FGDC SDI
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7 Federal GIS Framework Layers Governmental Boundaries Hydrography Geodetic Control Transportation Cadastral Elevation Ortho Imagery
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GIS Stacks Map Layers Numerous GIS layers are employed in: land development construction asset mgmt., land analyses map display etc. They are updated frequently. By whom and on what coordinate system?
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GIS Stacks Map Layers To accurately position and view features common to different maps or map layers (data sources). To compare and or analyze the relationships of features on one layer in terms of another layer or layers.
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Map Layer Alignment – How to…. Is that 1928845.23, 6354191.85 ? Where’s the pinche control layer? No, wait, that’s 1928835.23, 6354192.85
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How Do We Align Layers of a Data Sandwich? (or – Is Your Control Wimpy?)
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w/ the Geospatial Toothpick Equivalent! Geospatial Data Referenced to Geodetic Control
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Objective: Make Everything Line Up Geodetic Control is (or should be) the foundation for all geospatial products Without Geodetic Control as a basemap layer, GIS themes may not ALIGN well Source: Zurich-American Insurance Group
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Uniform Layer Registration via a Common, Coordinate-Based Control Network x 1a,y 1a,z 1a x 2a,y 2a,z 2a x 3a,y 3a,z 3a x 1b,y 1b,z 1b x 2b,y 2b,z 2b x 3b,y 3b,z 3b Every layer is expressed in the same coordinate system as the CONTROL LAYER. Same Datum & Coordinate System
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Common Reference Frame Implications are clear (Its about data and data availability) Importance of a common reference frame. Surveys – CCS, PRC (Horiz. & Vert.), FEMA & Elevations Civil Engineering Residential, Municipal, Statewide Construction, Transportation, Hydrography, Hydrology Public Safety First responders, Fire and Rescue, Seismic Early Warning GIS Projects -- multiple source layer control Future / Science FACTion / 3D / 4D aerial guidance, vehicle guidance, augmented reality
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Presentation Topics 1) Introduction of the GCWG. 2) Importance of a common reference frame. 3) Why GIS data needs Geodetic Control. 4) Geodetic control resources in California. 5) What's Next?
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Factious scenario GIS Data Integration Factious scenario State mandated County GIS data submission Parcel Data maintained by County Surveyor All Counties use the same coordinate system
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Factious scenario GIS Data Integration Factious scenario County “A”
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Factious scenario GIS Data Integration Factious scenario County “B”
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Factious scenario GIS Data Integration Factious scenario County “C”
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Factious scenario GIS Data Integration Factious scenario County “D”
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Factious scenario GIS Data Integration Factious scenario County “A”
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Factious scenario GIS Data Integration Factious scenario County “A”County “B”
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Factious scenario GIS Data Integration Factious scenario County “A”County “B” County “C”
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Factious scenario GIS Data Integration Factious scenario County “A”County “B” County “C”County “D”
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Presentation Topics 1) Introduction of the GCWG. 2) Importance of a common reference frame. 3) Why GIS data needs Geodetic Control. 4) Geodetic control resources in California. 5) What's Next?
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Geodetic Control California Spatial Reference Network (CSRN) Passive Monuments: Monuments set in the ground that require periodic re-observation to determine accurate relative position. Position only valid at the time of survey. Active Monuments (CGPS) CGPS station collects data 24 hours a day and its relative position is continually monitored. Positions that have become degraded due to earthquakes, subsidence and crustal motion can be updated.
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Presentation Topics 1) Introduction of the GCWG. 2) Importance of a common reference frame. 3) Why GIS data needs Geodetic Control. 4) Geodetic control resources in California. 5) What's Next?
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Summary of Situation Modern societies need GIS/geospatial data to analyze and manage a wide variety of resources. Geospatial data comes from different sources, but should have one thing in common: the frame of reference. Frame of reference must be defined by an accessible and maintained geodetic control network. Passive networks have limited value: difficult access, expensive to maintain, vulnerable to movement. Active networks (CGPS) are the future, and are the only viable and meaningful basis for geodetic infrastructure in California. California’s active geodetic network is in danger because funding sources are uncertain lack of understanding of importance no definitively appointed permanent steward (i.e. agency or organization with reliable annual funding)
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Role of GCWG GCWG appointed by California GIS Council to study and advise on geodetic control data standards and infrastructure. Assessment of situation warrants immediate action: outreach and information gathering. We will recommend solutions per our charter…...as soon as we figure out what to recommend. Meanwhile, we need your help with ideas and spreading the word.
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Ideas and Possible Solutions Education/Information Presentations, articles, and letters Educate surveyors & GISP’s on importance of geodetic control Be visible and accessible at survey/GIS conferences & meetings Talk and exchange ideas – someone may already know Research what other states have done – don’t reinvent wheel Legislation All official California GIS data to be tied to the geodetic control Create new agency? Fund existing agency? Advocacy Form technical and financial partnerships/consortiums Seek funding sources Lobbying and promoting
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Supporting an Accessible Geodetic Control Network for California Presented by: The California GIS Council's Geodetic Control Work Group (CGWG) Contact: A Growing Concern for the Geospatial, Land Surveying and Mapping Communities Thank you for your attention, participation and feedback! participation and feedback! Ryan HunsickerScott Martin rhunsicker@dpw.sbcounty.govscott.martin@dot.ca.gov
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