Tracy Fuller U. S. Geological Survey. February 24, 2016

Transcription

1 U. S. Geological Survey Arctic Elevation Data Involvement Statewide Alaska IfSAR Radar Collection Program Pan-Arctic Digital Elevation Map International Coordination Tracy Fuller U. S. Geological Survey February 24, 2016

2 Arctic Elevation Data Incredibly high-resolution elevation data is being created for the first time over the entire Arctic 60-degrees and north, and all of Alaska and Greenland All the data will be available to the public for free, unrestricted use

3 (graphics from MIT Libraries) Digital Elevation Model A Digital Elevation Model, or DEM, is a digital representation of terrain One common DEM structure is a regular grid of elevation heights The ground distance between points is called DEM density or resolution (examples: 1000m, 100m, 30m, 10m, 5m, 2m lower resolution means more detail)

4 Generate contours and shaded relief images for use on maps Generate derivative terrain slope and aspect models GIS applications/computer simulations: natural resource management wildfire growth forecasting glacial studies climate modeling flood and tsunami inundation modeling line of sight coastal erosion forecasting drainage flow accumulation aircraft safety and rescue operations Common DEM Uses (graphics from MIT Libraries)

5 Two Common DEM Subtypes Digital Surface Model, DSM, shows tops of trees and structures Digital Terrain Model, DTM, removes cover to show bare earth

6 Modern Elevation Collection Airborne or satellite stereo imagery position of sensor and common point on two images used to derive elevation Airborne or satellite radar active radar wave sent and received from a sensor Airborne lidar light pulse sent to earth and reflection returns to aircraft

7 Alaska Radar Elevation Project U.S. Geological Survey 3D Elevation Program (3DEP) Develop partnerships to collect enhanced elevation data over the conterminous United States, Hawaii, Alaska, U.S. Territories Collect Interferometric Synthetic Aperture Radar (IfSAR) for Alaska

8 Alaska IfSAR Deliverables Meet 2008 Alaska Statewide Digital Mapping Initiative requirements 5m elevation grids DTM and DSM delivered 3.6m vertical accuracy Meets National Map Accuracy Standards for 1:24,000-scale mapping (20-foot contours) DTM DSM

9 Alaska IfSAR Deliverables Orthorectified Radar Image (ORI) Pseudo image based on radar reflection intensity Useful for delineating surface water features, controlling new color imagery collects 62.5 cm resolution image pixels

10 Alaska IfSAR Deliverables Digital Breaklines Delineate ridges, valley bottoms, river banks Created to help enforce correct DEM water flow and improve overall DEM quality Useful for editing Alaska National Hydrography Dataset

11 Alaska IfSAR Deliverables GPS Survey Control Check Points Over 800 points being collected statewide X, Y, Z locations used to assess IfSAR quality Useful for improving and assessing other imagery and elevation projects

12 $62M total project cost Alaska IfSAR Collection Status Volunteer contributions from State of Alaska and Federal Agencies 62% fully funded, will surpass 70% in FY2016 Attempting to complete northeast AK summer 2016 All deliverables being made available for free to the public

13 Pan-Arctic Digital Elevation Map Arctic Council Initiative, U.S. Chairmanship Sponsored to Address the Impacts of Climate Change Proposal Accepted by Arctic Council Spring 2015 Improve public access to high resolution Arctic elevation data Single point of access Arctic Spatial Data Infrastructure, representing the national mapping agencies of the eight Arctic nations, coordinate international support to the project Arctic Council Conservation of Flora and Fauna Working Group (CAFF) to monitor progress Polar Geospatial Center ArcticDEM Announced by U.S. President September 2015 Elegant solution to the original initiative

14 USGS USGS and Arctic SDI Support of PGC ArcticDEM Coordinate international support to Polar Geospatial Center Organize series of workshops with Arctic nation representatives Interface with Arctic SDI nations and Polar Geospatial Center Produce progress reports for CAFF and Arctic Council Coordinate international requirements gathering activities Arctic SDI Arctic nations can provide control point data to improve DEM accuracy Arctic nations can review data and report issues to PGC Arctic nations can edit PGC delivered data and create an improved national product Arctic nations can submit improved data to PGC and other data distributors in the future