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.

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