1. Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS) Churngwei Chu [email: Churgwei.Chu-1@NASA.GOV], Fenny Wang, Walt Baskin, and Kay Rowe Science Systems and Applications, Inc. Hampton, VA and Juliet Pao NASA Langley Research Center Atmospheric Science Data Center Hampton, VA September 26, 2007 National Aeronautics and Space Administration www.nasa.gov

2. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ Outline Introduction Geodetic Model vs Geospatial Model (PostGIS)‏ Steps to Project a Polygon in Geodetic Model to a 2-D map Results Summary & Future Work

3. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 3 Atmospheric Science Data Center Radiation Budget Clouds Aerosols Tropospheric Chemistry Providing data services for over 42 Projects In 2006, 251 Terabytes of data distributed to 20,500 customers in 176 countries >2 Petabytes of data in the archive Increasing rate of ~28 Terabytes/month Processing, Archiving, and Distributing Earth Science Data at NASA Langley Research Center http://eosweb.larc.nasa.gov

4. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ NASA's Earth Observation System (1/3)‏ EOS Spacecraft EOS Ground Stations

5. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ NASA's Earth Observation System (2/3)‏ Data Processing & Mission Control Data Transport to Data Centers

6. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ NASA's Earth Observation System (3/3)‏ Data Centers Instrument Teams/SIPS Research Users Education Users Value-Added Providers International Partners & Data Centers Interagency Data Centers Internet

7. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 7 ANGē (Archive Next Generation)‏ Distributed, multi-tier, service-based architecture enabling new methods for managing science data Goals Merge two systems into one. Improve efficiency and automation. Use commodity hardware (PCs) to reduce hardware and maintenance cost. Use Open Source Software such as PostgreSQL/PostGIS, JBoss and GNU compilers.

8. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 8 Sample Data File

9. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 9 Data Flow for Informix Data GeoBox((-60,80),(60,-160),ANY,(1993-12-31 22:30:00,1994-01-01 01:30:00))‏ Informix Geodetic Datablade GRing

10. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 10 Geo-object Types –Polygons –Points –Bounding boxes – Line strings Operations Intersection between a query bounding box and above data types.

11. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 11 Challenges of Moving Data to PostGIS Informix Geodetic Datablade uses geodetic model – spherical coordinate. Geospatial Model (PostGIS) uses projections – planar coordinate. Invalid polygons created by GRing stored in Informix. GRing still generates some invalid polygons.

12. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 12 Geodetic Model - Polygon “A line segment is represented as a geodesic. On an ellipsoidal datum, a geodesic is the shortest path between two points.” -- Informix Geodetic DataBlade Module User's Guide “You must specify the vertices in a ring that encloses a region so that the interior of the polygon is on your left as you traverse each ring from vertex to vertex.” -- Informix Geodetic DataBlade Module User's Guide

13. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 13 Sample Data Across Anti-meridian in Geodetic Model

14. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 14 Cylindrical Projection in Geospatial Model

15. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 15 Projected Geoobj from GRing on 2-D map

16. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 16 Polygons in 2-D Map

17. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 17 Sample Data Covering South Pole in Geodetic Model

18. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 18 Cylindrical Projection in Geospatial Model

19. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 19 Projected Polygon on 2-D map

20. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 20 Data Flow for PostGIS Data GRing Polygon(.......)‏ ASDC Conversion Process A set of counter-clockwise sub-polygons A set of clockwise sub-polygons Type of the original projected polygon PostGIS

21. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 21 Steps to project a polygon into PostGIS Model 1)Project a polygon to 2-D map by adding points on anti-meridian. 2)Determine type of projected polygon: a line string a clockwise polygon a counter-clockwise polygon 3)Partition the mapped polygon into two groups of sub-polygons, clockwise and counter- clockwise. 4)If the polygon is projected into a line, more edges are added to enclose north pole or south pole which becomes a counter-clockwise polygon.

22. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 22 Polygon Covers South Pole Generated by GRing

23. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 23 Polygon in 2-D Map

24. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 24 Covered Region in 2-D Map

25. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 25 Data Covers both poles in Geodetic Model

26. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 26 Cylindrical Projection in Geospatial Model

27. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 27 Original Polygon From GRing on a 2-D map

28. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 28 After Adding Points on Anti-meridian

29. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 29 Two Clockwise Polygons

30. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 30 Intersection Query In our PostGIS DB table, we have four columns to keep geo-spatial data, a polygon type, counter-clockwise sub-polygons, clockwise sub-polygons, and a polygon (text format) in the geodetic model. The geometries, points or line strings are stored in the column with counter-clockwise sub- polygons. The following is a sample intersection query with bounding box (-40, -40) and (40, 40). select granule_id from ctest where (((polygon_type > 1) and intersects(geoobj_ccw, GeomFromText('POLYGON((-40 -40, -40 40, 40 40, 40 -40, -40 -40))', -1)) and (geoobj_cw is null or not contains(geoobj_cw, GeomFromText('POLYGON((-40 -40, -40 40, 40 40, 40 -40, -40 - 40))', -1)))) or (polygon_type = 1 and ((intersects(geoobj_ccw, GeomFromText('POLYGON((-40 - 40, -40 40, 40 40, 40 -40, -40 -40))', -1)) or (geoobj_cw is null or not contains(geoobj_cw, GeomFromText('POLYGON((-40 -40, -40 40, 40 40, 40 -40, -40 -40))', -1))))))) order by granule_id;

31. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 31 Results 1399 0(60, 160)(89.9, -160)‏5 1453 0(-89.9, -120)(-60, -60)‏4 141814171(60, 60)(89.9, 120)‏3 1413139815(-40, -40)(40, 40)‏2 1807179413(-40, 120)(40, -120)‏1 No. of returned records from PostgreSQl/PostGIS No. of returned records from Informix No. of Different Records Bounding Box

32. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 32 Summary Improved geospatial queries on a global scale. Future Work Enhance Performance of the algorithm and the queries. Move our geo-spatial data in Sybase Space Query Server to Postgres/PostGIS. Integrate with other open source GIS utilities and applications to expand ASDC user community.

33. National Aeronautics and Space Administration Transitioning Low Earth Orbit Satellite Archive Data from Informix (Geodetic DataBlade) to PostgreSQL (PostGIS)‏ 33 SignOffPage