Stuff I'm working on using Google Maps API

  • wemapr Create maps from charts you've found.
  • wepoco Displays recent daily rainfall totals for Africa.
  • map-grid  A tool for testing map tiles like those on the Wepoco site.

[Useful resources - Google Maps Deconstructed]

Map generator using Proj4 

Format width= height=
Note. Changes to width and height will require an adjustment of x_0 and y_0 to re-centre the map, and an adjustment of to_meter if a scale change is required.

Meteosat/MSG map (geostationary space view)

See also Meteosat coordinates

size= (width and height - normally 3712 for MSG or 2500 for Meteosat)
satellite_generation= lon_0=

Polar stereographic map

lat_0= lon_0=
To place the above point at the centre of the image
x_0=width*to_meter/2.0
y_0=height*to_meter/2.0
x_0= y_0= to_meter=

Proj4

Reference material for Proj4 can be found at http://remotesensing.org/proj/ or http://proj.maptools.org/

proj= ellps= datum=
lat_0= lon_0= lat_ts=
a= h= b=
f= rf= e= es=
x_0= y_0= to_meter=

Notes

The following values produce a fair approximation to the Meteosat Second Generation (MSG) space view. It is only approximate because the proj4 nsper projection assumes a spherical earth. (This isn't the case for the usual proj4 map projections which are generally very accurate.)
width=3712 height=3712
proj=nsper a=6367.453 h=34700.0 to_meter=3.0137 lon_0=0.0 lat_0=0.0 x_0=5591.92 y_0=5591.92