http://www.web3d.org/x3d/content/examples/Basic/#Geospatial
http://web.csulb.edu/~rodrigue/geog140/lectures/projections.html
- http://www.colorado.edu/geography/gcraft/notes/mapproj/gif/unproj.gif
- used to check GeoTouchSensor reported Lat, Lon
World.x3d and derived tests have a problem with their GeoElevationGrid: 
- its off in zSpacing=4.34 = 180/42 should be 4.39= 180/(42-1) assuming heights include N-90 and N+90
- leaving holes at north or south pole depending on the browser
- and causing latitude error in height and texture coordinate interpolation


2008 draft geospatial enhansements
Andreas: there may be planetary geoSystems or spatial reference frames proposed
in the enhanced geospatial component proposal.
http://www.igraphics.com/Standards/EnhancedGeospatialComponent_2007_10_30/Part01/components/geodata.html
http://www.sedris.org/wg8home/Documents/18026_FDIS/C030811e_FILES/MAIN_C030811e/ISOIEC_18026E_TOC.HTM
March 2020: Dick Puck gave me the same spec which hasn't been accepted (yet?)


18026:
https://www.iso.org/standard/54166.html
- its from 2009, a year after web3d 2008 enhansed geospatial proposal
- (previous versions of 18026 submissions were 'withdrawn')
x it talks about SRM, not SRF, so the 2008 proposal has different terminology
x costs 198 CHF. I don't have 198 CHF on me right now.
http://standards.sedris.org/18026_Ed2/ISO_IEC_18026_Ed2/ISO_IEC_18026_COVER.html
- sedris free originator copy of 18026
- its vast and (like DIS) not practically implementable. 
- Andreas said: Better to use sedris .cpp library if you can.
http://standards.sedris.org/
x you have to sign in
x still problem of how to do convenience-constants in x3d 
--- string or some A:B thing included in xml

2020
- working on WM web mercator
x Apr 26,2020 geo inside Laerset.Layer does not work properly - see World/World33stars_layersetHud.x3d