1. Feedback on the New Datums Reference Frames 2015 Geospatial Summit April 14, 2015 Amar Nayegandhi Dewberry Consultants LLC

2. Our major products/services which will be affected by the new reference frames: All products of the 3D Elevation Program (3DEP) QL2 LiDAR nationwide QL5 IFSAR of Alaska Elevations could change by up to 30 cm Digital orthoimagery and planimetric maps for all clients Horizontal coordinates could change by up to 1.5 meters Flood Insurance Studies for FEMA Revised studies often use H&H analyses with prior datums Our preparations to date include: Our DTMs & DSMs of Alaska are also being delivered with ellipsoid heights so we can apply the new geopotential reference frame to easily re-compute new orthometric heights Preparation

3. The problem we hope the new geopotential reference frame will solve Per Geodetic FormulaGEOID06GEOID12A H (orthometric height)614.000 m614.000 m ? + N (geoid height)13.99 m 14.070 m = h (ellipsoid height)627.99 m628.070 m but h (ellipsoid height) = 628.092 m, a difference of 10.2 cm (GEOID06) and 2.2 cm (GEOID12A) With new reference frames, we hope we’ll be able to compute orthometric heights accurate to 1 cm when mapping ellipsoid heights from LiDAR and IFSAR and adding the geoid height Note 8 cm difference in geoid height between Geoid06 and Geoid12A

4. We are excited because... Expected advantages of the new datums for your organization, its products, or services We hope that NGS Data Sheets and survey monuments will become relics of the past as we come to rely on the new National Spatial Reference System (NSRS) GPS users will be forced to rely on CORS as the prior use of inaccurate and un- maintainable survey monuments are phased out We hope we can get standard vertical datums offshore (e.g., Hawaii, PR, USVI) We hope we can more-easily link to the dynamic ITRF, recognizing that the land continues to move horizontally and vertically All horizontal and vertical coordinates should be more accurate horizontally and vertically We are concerned because... Expected challenges of the new datums for your organization, its products, or services Our biggest challenge will be to update all the elevation data, orthoimages and other geospatial datasets produced with prior datums (Legacy data!) FEMA often revises Flood Insurance Studies by updating prior hydrologic & hydraulic (H&H) models prepared with older datums; may take decades to fix Advantages / Challenges

5. The tools, products, or services we need most (from NGS or others) are: Whereas NADCON, VERTCON and CORPSCON converts data easily from NAD27 and NGVD29 to NAD83 and NAVD88, we will need new transformation tools for the new datums GPS and GIS vendors should update their software to incorporate the new geometric and geopotential reference frame The outreach we need most (from NGS or others): NGS should host bi-annual summits and quarterly webinars NSPS should distribute sample language to update state legislation that references NAD 83 NGS will need a “full court press” to get other federal and state agencies to act proactively to prepare for the future and to implement the new reference frames when ready Transition Tools / Outreach Needs

6. Thank you. Questions? Amar Nayegandhi Director of Remote Sensing Dewberry anayegandhi@dewberry.com Ph: 813 421 8642 (office) Cell: 727 967 5005