[OpenLayers-Users] Tips for creating custom WMS base map?

[Jennifer Strahan]

Hello,

Does anyone on the list have any tips/ tricks to keep in mind when 
creating a custom WMS base map?  I'm converting a Mapserver 
application to the OpenLayers interface and creating a Mapserver WMS 
service (or set of services) based on my original mapfile.

I'm wondering what approach I should take to get the best performance 
and have some questions.  First, here are the basics of the base map 
I'm creating:

Extent is entire state of California.  I will have 10 zoom levels 
from 1: 5M to 1:9,000.  Layers include hillshade (90m, 30m), 
waterbodies, protected lands, urban lands, detailed local roads, 
major roads, highways, cities, county lines, campgrounds, hiking trails...

Some questions:

1.  Would it be best to create a separate base map for each zoom 
level and then use Tilecache to create cached tiles?  One issue with 
this idea is that if I use PNG24 output the file sizes are 
larger.  If I use JPEG, the sizes are smaller but the vector data 
looks fuzzy.

2.  Or, should I create two raster-only base maps (one for small 
scale and one for large scale) and use conditions in OpenLayers to 
turn on the vector layers at the appropriate zoom levels?  The issue 
with this approach is that the raster and vector data loads 
separately and can be confusing to the user.

3.  Are there other methods that I should consider?  Which options 
would yield the best performance?

4.  If I create cached tiles, how can I determine how much server 
storage space I need for all of the tiles?

Any suggestions would be much appreciated.


Thanks,
Jennifer






Jennifer Strahan
GreenInfo Network - 1996-2006: A Decade of Mapping the Public Interest
116 New Montgomery  Street   Suite 738  San Francisco CA  94105
PH: (415)979-0343 x306    Fax:  415-979-0371     Web:  www.greeninfo.org