Welcome to the Alaska Height Modernization Forum 5

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Welcome to the Alaska Height Modernization Forum 5 October 2005

Welcome to the Alaska Height Modernization Forum 5 October 2005

Alaska Height Issues The state does not have adequate vertical coverage n Legally established

Alaska Height Issues The state does not have adequate vertical coverage n Legally established vertical datum is the North American Vertical Datum of 1988 n In Alaska, we have a few NAVD 88 points n Most are NGVD 29 n Coastal datum is Local Tidal Datum n

What’s the Problem? Having a conglomeration of disparate datums means commonality is not inherent

What’s the Problem? Having a conglomeration of disparate datums means commonality is not inherent n Vertically, Alaska has challenges n Local Tidal Datums n Mean Sea Level, aka NGVD 29 n NAVD 88 n Ellipsoid heights not reduced to ground n

Alaska’s Current Horizontal Net n In the NGS Database 24028 10043 have been visited

Alaska’s Current Horizontal Net n In the NGS Database 24028 10043 have been visited and are still viable n 13905 are missing or have never been recovered since their installation n 58% of the current horizontal network is suspect n

Alaska’s Current Vertical Net n In the NGS database - 3381 1660 have been

Alaska’s Current Vertical Net n In the NGS database - 3381 1660 have been visited and are still viable n 1721 are missing or have never been recovered since their installation n 50% of the current vertical control network is suspect n

Bench Marks per Mile n 18, 168 miles of road and rail in the

Bench Marks per Mile n 18, 168 miles of road and rail in the state n n State Highways Railroad 3381 markers for 18, 168 miles ≈ 5 ½ miles per marker How do we tie vertically anything off the road network?

Horizontal n Programs to improve the latitude and longitude coordinates to the NAD 83

Horizontal n Programs to improve the latitude and longitude coordinates to the NAD 83 HARN n CORS n PBO n HEIGHT MODERNIZATION n

HARN

HARN

Continuously Operating Reference Stations

Continuously Operating Reference Stations

Plate Boundary Observatory

Plate Boundary Observatory

What we should consider n Become aware of the issues of the Alaska control

What we should consider n Become aware of the issues of the Alaska control network n What the NGS Ht Modernization program is n Options for improvement n How much this could cost – n n n Finances Manpower Time

What we can have with Ht Mod n n n n Improved disaster preparedness

What we can have with Ht Mod n n n n Improved disaster preparedness Improved tectonic modeling Improved surveying techniques Better resource management through GIS analysis More confidence in navigational surveys (better charting) More confidence in airport surveys Better coastal erosion analysis Money-saving efforts to improve our position in the horizontal and vertical world

Today’s Agenda 8: 30 Intros and Goals of the Forum Dowling 8: 45 Current

Today’s Agenda 8: 30 Intros and Goals of the Forum Dowling 8: 45 Current Issues in the State, Current Control Status 9: 00 Geotechnical Issues and Obstacles to Up-to-Date Control Freymueller 10: 00 Break 10: 15 NGS Height Modernization Program Blackwell 11: 15 Height Modernization in Other States Carlson 12: 00 Lunch (on your own) 1: 30 Height Modernization Functions, Applicability to and Challenges for Alaska Smith 2: 30 Breakout sessions, Brainstorming Group 3: 45 Wrap-up with Questions and Answers 4: 00 Adjourn