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Mapping the world beyond web mercator

Mapping the world beyond web mercator

Most popular mapping presentations today, ranging from clients to servers, show and discuss only maps in EPSG:3857, the popular Mercator derived projection used by OSM as well as
most commercial tiles providers.

There is however an interesting, exciting world of map projections out there, that are still being used in a variety of context. This presentation will introduce the advancement made in GeoTools and GeoServer to handle those use cases, where users have a worldwide data set, and need to view all or part of it in multiple projections, some of which valid in a limited area, and requiring the software to perform a proper display of it on the fly, without any preparation.

We’ll discuss GeoTools/GeoServer “advanced projection handling” manages to deal with these cases, wrapping data, dealing with the poles and the dateline, cutting on the fly excess data, densifying on the fly long lines as needed to ensure a smooth reprojection, for a variety of cases, ranging from seemingly innocuous datum shifts, maps having the prime meridian over the pacific, and the various tricks to properly handle stereographic, transverse mercator, Lambert conic and other limited area projections against world wide source data sets.

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Simone Giannecchini
PRO

September 02, 2018
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Transcript

  1. Mapping beyond web mercator Ing. Andrea Aime GeoSolutions

  2. GeoSolutions ⚫ Italian SME ⚫ Expertise • Image Processing, GeoSpatial

    Data Fusion • Java, Java Enterprise, C++, Python • JPEG2000, JPIP, Advanced 2D visualization ⚫ Supporting/Developing FOSS4G projects ⚫ GeoServer, MapStore ⚫ GeoNetwork, GeoNode, Ckan ⚫ Clients ⚫ Public Agencies ⚫ Private Companies ⚫ http://www.geo-solutions.it FOSS4G 2018, August 29th/31st, Dar Es Salaam
  3. Why Web Mercator

  4. Why: it’s everywhere, it’s free FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  5. Why: familiar FOSS4G 2018, August 29th/31st, Dar Es Salaam

  6. Why: easy FOSS4G 2018, August 29th/31st, Dar Es Salaam

  7. Why: fair to the dateline FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  8. Some reasons to avoid Web Mercator

  9. One reason to rule them all FOSS4G 2018, August 29th/31st,

    Dar Es Salaam
  10. Area distortion in web mercator FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  11. Equal-area maps to the rescue Lambert azimuthal equal area Mollweide

    Equal Earth FOSS4G 2018, August 29th/31st, Dar Es Salaam
  12. FAO example FOSS4G 2018, August 29th/31st, Dar Es Salaam

  13. Distance perception http://braincrunch.tumblr.com/post/23672142073/mercators-egg FOSS4G 2018, August 29th/31st, Dar Es Salaam

  14. Equidistant maps to the rescue FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  15. Example: weather radar maps https://weather.gc.ca/radar/index_e.html?id=xsm FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  16. Who ate the poles?! FOSS4G 2018, August 29th/31st, Dar Es

    Salaam
  17. Polar stereographic http://www.add.scar.org/home/add6 FOSS4G 2018, August 29th/31st, Dar Es Salaam

  18. Polar stereographic http://www.polarview.aq/ (also GeoServer powered) FOSS4G 2018, August 29th/31st,

    Dar Es Salaam
  19. FAO Species Distribution FOSS4G 2018, August 29th/31st, Dar Es Salaam

  20. The beginning of the end? FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  21. Handling all these projections

  22. Should be simple no? FOSS4G 2018, August 29th/31st, Dar Es

    Salaam
  23. One (tragic) example FOSS4G 2018, August 29th/31st, Dar Es Salaam

  24. What’s going on? FOSS4G 2018, August 29th/31st, Dar Es Salaam

  25. And then… AUTO codes FOSS4G 2018, August 29th/31st, Dar Es

    Salaam
  26. Automate! With APH FOSS4G 2018, August 29th/31st, Dar Es Salaam

  27. APH step 1: which data to read Requested Read FOSS4G

    2018, August 29th/31st, Dar Es Salaam
  28. APH step 2: cut excess data FOSS4G 2018, August 29th/31st,

    Dar Es Salaam
  29. APH step 3: data wrapping Requested Read FOSS4G 2018, August

    29th/31st, Dar Es Salaam
  30. APH step 4: detect dateline crossing FOSS4G 2018, August 29th/31st,

    Dar Es Salaam
  31. Some side by side examples FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  32. PDC Mercator, EPSG:3832 Antactica was here… Funny Greenland … FOSS4G

    2018, August 29th/31st, Dar Es Salaam
  33. Lambert conf. conic, EPSG:2225 ?!! FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  34. Datum change, ED50, EPSG:4230 FOSS4G 2018, August 29th/31st, Dar Es

    Salaam
  35. UTM32N, EPSG:32632 FOSS4G 2018, August 29th/31st, Dar Es Salaam

  36. No reprojection, but Pacific centered Would really like to see

    Americas here… FOSS4G 2018, August 29th/31st, Dar Es Salaam
  37. Some other hard data

  38. Data between 0 and 360 FOSS4G 2018, August 29th/31st, Dar

    Es Salaam
  39. Satellites satellites FOSS4G 2018, August 29th/31st, Dar Es Salaam

  40. And more satellites FOSS4G 2018, August 29th/31st, Dar Es Salaam

  41. Final words

  42. APH step 2.5:dynamic densification FOSS4G 2018, August 29th/31st, Dar Es

    Salaam
  43. In summary FOSS4G 2018, August 29th/31st, Dar Es Salaam

  44. That’s all folks! Questions? info@geo-solutions.it