[postgis-users] Interesting Datum Conversion Issue

[James G Wilkinson]

A situation has occurred that I am having difficulty getting my hands 
around.
I have a single point with the following attributes:

lon = -115.10101
lat = 36.15526
PROJ4 entry in SPATIAL_REF_SYS
+proj=longlat +ellps=GRS80 +datum=NAD83 +no_defs

In ARC/Info, when I project this point to the following:

projection: LAMBERT
datum: NONE
units: meters
spheroid: sphere
1st parallel: 33.0
2nd parallel: 45.0
central meridian: -118.0
latitude of origin: 37.0
false easting: 0.0
false northing: 0.0

I get back a point at  y-coord = -89372 m.

The above projection is entered into my SPATIAL_REF_SYS table
with the following PROJ4 parameters (SRID=888889):
+proj=lcc +lat_1=33.0 +lat_2=45.0 +lat_0=37.0 +lon_0=-118.0 +x_0=0 
+y_0=0 +a=6370997.0 +b=6370997.0 +units=m

Now with PostgreSQL v.7.4.8, PostGIS v.0.9.1, and PROJ4 v.4.4.7,
this same point using SELECT Y ( TRANSFORM (the_geom, 888889) ) FROM 
spatial.pt_test
returns -89074 (which is close enough for my work.....for now).

When I migrated to PostgreSQL v.8.1.3, PostGIS v.1.1.2, and PROJ4 v.4.4.9,
my SELECT returns -109641 (!! and this is what baffles me !!).

Any help that folks can lend will be greatly appreciated.

Regards,

Jim
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