[postgis-users] Database design for LIDAR data

[Jonathan Greenberg]

Folks:

This topic I believe has been brought up before, but I thought I'd
send an email since I'm a bit of a noob with POSTGIS.  We have a large
collection of Lidar points that I would like to perform spatial
querying on (e.g. give me all points within a certain bounding box).
The data (currently in LAS format, but easily loadable into the DB),
is tiled up into smaller subsets.  The data is x,y,z,intensity (and
some other attributes that aren't so important)  I have a few
questions:

1) Should I load ALL of the LAS files into one massive table for
querying (this is going to be a LOT of points).
2) If not, is there a trick where if I load up each LAS file into a
separate table (which would, in theory be preferable since I'd like to
do some testing before dealing with a database of this size), but
somehow when I do a spatial query, the query can span multiple tables
(e.g. say the query box is at the intersection of two adjacent tiles)?

Related: what is the most efficient way to do a spatial query that
effectively "rasterizes" this data, e.g. the min z value between x1
and x2, and y1 and y2, where x2-x1 and y2-y1 are the x and y pixel
sizes?  I'm not talking about interpolation, I'm talking an exact
query.

Thanks!

--j

-- 
Jonathan A. Greenberg, PhD
Assistant Project Scientist
Center for Spatial Technologies and Remote Sensing (CSTARS)
Department of Land, Air and Water Resources
University of California, Davis
One Shields Avenue
Davis, CA 95616
Phone: 415-763-5476
AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307