3. Quadrilateral Data Structure Geodetic latitude and longitude on GRS80/WGS 84 ellipsoid(NAD 83) Grid cell resolution constant N-S but progressively finer E-W resolution from equator to pole

4. ETOPO5 Global Digital Elevation Model

5. ETOPO5 Digital Elevation Model (DEM) Row Major Order

6. World Map (left) made from ETOPO5 DEM

7. ETOPO2 Global DEM ETOPO2 Global DEM from National Geophysical Data Center from National Geophysical Data Center

8. Piece of a World Map made from ETOPO2 DEM

9. Worldwide Land And Sea Elevation Data In Meters (3.7x3.7km cells at equator) Technical Specifications (0,0)(10799,0) (0,5399) (10799,5399) Row Major Order

10. ) Technical Specifications (0,0)(10799,0) (0,5399) (10799,5399) 2-byte signed integer data 5400 rows by 10800 columns 116,640,000 byte dataset Row Major Order

11. ETOPO1 Global DEM ETOPO1 Global DEM from National Geophysical Data Center from National Geophysical Data Center

12. Worldwide Land And Sea Elevation Data In Meters (1.85x1.85km cells at equator) Technical Specifications (0,0)(21599,0) (0,10799) (21599,10799) Row Major Order

13. Technical Specifications (0,0)(21599,0) (0,10799) (21599,10799) Row Major Order 2-byte signed integer data 10800 rows by 21600 columns 466,560,000 byte dataset

14. Map made from ETOPO1 data

15. GLOBE 30” x 30” Global Land DEM

16. Globe 30” x 30” grid cell data structure and tiling, format, and dataset size

17. Alaska Map Made From Globe Data

18. STRM30 Plus STRM30 Plus

19. NGDC 3 Arc-Second Coastal Relief Model

20. Map made From Coastal Relief Model

21. National Elevation Dataset (NED) One-second Grid For All U.S. States except…

22. Two-second Grid For Alaska

23. National Elevation Dataset (NED) Data Format and Tiling Scheme

24. Web Mapping Using NED 1” x 1” Data

25. National Elevation Dataset (NED) 1/3 rd and 1/9 th second Grids For Certain Areas

26. 1/3 rd Second Maps for Monterey

28. Ordering SRTM Data Data Products Shuttle Radar Topography Mission (SRTM)

29. SRTM Data Completeness Problems

30. Map Projection-based Raster Data

31. USGS 7.5’x7.5’ 10m DEMs for Oregon

32. USGS 7.5’x7.5’ 10m DEMs for Oregon Available only in SDTS Format

33. USGS 1:24000-scale Digital Raster Graphics (DRG) scanned topographic maps of U.S. states and territories Scanned at 250 dpi

34. USGS 1 km Global Land Cover Characteristics database (GLCC) Classified 1km x 1 km AVHRR satellite data Gridded on Interrupted Goode Homolosine and Lambert Equal Area Map Projection Surfaces Now in 30 arc second Quadrilateral Form Several Land Cover Classification Systems Used