1. 1 HDF-EOS Vector Data Eugene Chi, Liping Di, R.Suresh NASA/RITSS Email: suresh@rattler.gsfc.nasa.gov

2. 2 INTRODUCTION HDF EOS library was primarily designed to support raster data from Terra and other follow on projects An increasing need to use Terra data with GIS applications for regional and local use Integration of Terra data with vector data will create new applications and usage Many GIS users will be able to access and use Terra data

3. 3 HDF EOS Library HDF-EOS Swath HDF-EOS GRID HDF-EOS Point

4. 4 Vector Data Requirements Need to support additional data types GIS Users require vector data support ESIP user community requested vector data support Many ESIP investigators use vector data with Terra data Advantages: Terra data will be available to a new community of GIS users Increase in Terra data use for many new applications Vector data support will increase data inter use Enhances data interoperability Support for OGC WMT implementation

5. 5 A Vector Data Set

6. 6 A Vector Structure 3.0 15.0 1.0 15.0 10.0 1.0 PX 10.0 Building NumberBuilding Name 1Physics 2Earth Science 3Mathematics 4Chemistry Point Geometry and Attribute

7. 7 A Vector Structure (cont) Line IDPXPY 11.0 110.01.0 115.0 2 23.010.0 33.010.0 31.0 Street Name Campus Drive Stadium Drive Valley Road Line Geometry and Attribute

8. 8 A Vector Structure (cont) 12 13 Polygon IDLine ID 11 Section Main Campus Line IDLeft PolyRight Poly 11 21 31 Polygon Geometry and Attribute Contiguity

9. 9 Components of the Vector Interface n Access n Definition n Basic I/O n Inquiry n Subset

10. 10 The Vector Interface

11. 11 The Vector Interface (cont)

12. 12 Vector Subsetting Features n By Geolocation –VCdefboxregion –VCregioninfo –VCregionrecs –VCextractregion

13. 13 Tips on Writing a Vector n Attribute fields –The name, type, order, and number of the attributes of point, line, and polygon are defined by users when first using them in a vector structure. –Once defined, the attributes are fixed with respect to the vector.

14. 14 Compression Method for Vectors n NONE