Export ESRI:54099 WGS_1984_Spilhaus_Ocean_Map_in_Square as PROJ string

[rouault]

and fix ESRI:54098 mapping to use +proj=spilhaus with +k_0=sqrt(2)

On top of PR #4401

With it:
~/proj/proj/build_cmake$ echo 41.34837298 -117.28057438 | bin/cs2cs EPSG:4326 ESRI:54099
12421874.60 -14140625.11 0.00

Which matches ESRI values of #1851 (comment)

[jjimenezshaw]

I tried to make spilhaus projections flexible enough to match ESRI adams ws2.
The only difference is the scale factor affected by sqrt(2).
But I only had the points reported by @mdsumner in the spilhaus issue #1851
If you set spilhaus settings +lat_c, +lon_c, rot and azi all to 0, you should have an Adams_ws2

[rouault]

If you set spilhaus settings +lat_c, +lon_c, rot and azi all to 0, you should have an Adams_ws2

yes I tested that.

We could indeed map ESRI Adams_WS2 as PROJ spillhaus with Scale_factor * sqrt(2) if we get confirmation that there's also a sqrt(2) factor between ESRI:54098 WGS_1984_Adams_Square_II and PROJ's +proj=adams_ws2, hence my request to the community for test points for ESRI:54098 in #1851 (comment) . Or maybe @melitakennedy can provide us with some?

[rouault]

@kbevers I believe this PR / #4401 should be merged before 9.6.0 is cut, even if they are not "perfect", if we don't get inputs before that. For the record, I won't be available next week.

[rouault]

PR updated to be more general and also replicate (almost) ESRI results for ESRI:54098

Thanks to @kgjenkins for https://github.com/kgjenkins/test-coordinates/blob/main/coordinates.csv test points:

$ echo 80 -170 | bin/cs2cs EPSG:4326 ESRI:54098
-9457033.96 13296625.29 0.00

vs ESRI: -9457034.1001 13296625.6969

$ echo 80 -170 | bin/cs2cs EPSG:4326 ESRI:54099
-6624823.23 14253430.38 0.00

vs ESRI: -6624823.16092 14253430.1778

[kbevers]

I believe this PR / #4401 should be merged before 9.6.0 is cut, even if they are not "perfect",

I agree, but now that the problem has been dealt with we are in an even better position. I expect to put out the release candidate at the beginning of next week.