projection lon_0

[John Bolster]

Hi all,

Thanks to all of you who have helped me so far.

I'm attempting to reproduce the projection used by the Census Bureau in
their Tiger map browser. It's a sinusoidal projection, but it appears to be
centered at the center of the rendered map each time rather than having one
origin. If I set my projection to sinu and manually set lon_0 to the same as
the map center it looks right, but I want lon_0 to automatically follow the
map center.

Is there any value I can pass in the url to set the lon_0 each time? I've
tried &map_projection_lon_0= and it doesn't work. Any ideas?

Thanks,
John