New England Height Issues

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New England Height Issues

• NGS Height-Mod Forum
• Nashua, NH
• December 10, 2009
• Dan Martin
• National Geodetic Survey
• Vermont State Advisor

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What do we have in common?

• All NE states are wet and all but one state has
  a salty coastline
• Much of our topography is similar
• Shared riverine network
• Life is good

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How can Height-Mod help?

• Disaster preparation/mitigation
• Evacuation Routes for coastal storms
• Coastal storm inundation models
• Stream flow models to predict riverine flooding
• Flood plain mapping
• Point and non-point pollution/runoff models

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Hancock, VT
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Alstead, NH
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Flood plain mapping
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• Construction
• Dams, levees, riverine management
• Roads and bridges
• Building and other developments

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• Coastal conservation
• Accurate ties between geodetic and tidal datums
• Planning ecosystem restoration projects
• Shoreline restoration projects

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Narragansett Bay National Estuarine Research
Reserve
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• Nautical charting and efficient shipping
• Support NOAAs Physical Oceanographic Real-Time
  System (PORTS)
• Supports VDATUM

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PORTS
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NGSIDB BM Status (1st, 2nd order)
CT MA ME NH RI VT
In NGSIDB 2599 1125 5401 1092 1380 2158
Poor 31 24 118 20 19 17
Not Found 281 150 1048 218 196 363
Not Rec since Monumented 533 254 1659 216 160 461
Last Rec 1990 1570 584 4475 689 857 374
Last Rec 1980 160 499 3434 531 277 331
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NE Vertical Control
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Height-Mod means More Marks
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More Marks
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More Marks
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More Marks (OPUS_DB on BMs)
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(No Transcript)
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Using Real-Time
95(RMSEr) (m) 95(RMSEz) (m)
RT1 0.032967 0.018825
RT2 0.033251 0.0237233
RT3 0.036622 0.027924
RT4 0.036143 0.026851