--- Begin Forwarded Message ---
Date: Fri, 18 Feb 2000 22:02:15 +0100 (CET)
From: Umberto Fracassi <[log in to unmask]>
Subject: Lat/Long -> UTM
Sender: Umberto Fracassi <[log in to unmask]>



Ciao all,

this might be a bit off topic...

I have various data (Landsat TM, airphoto mosaic, DEM), expressed within
ED50, UTM Zone 32N, coordinates as EN meters, on which I should superpose
a layer embedding names of localities. These latter came to me as an ascii
file (lat, long, name), the coordinates expressed in degrees and
referenced to Greenwich (as opposed to my data, whose bottom line is the
DEM, and that was interpolated from contours digitized from the official
Italian cartography (the area is central Italy..). All longitude values
range within 12-14 degrees (i.e., they are referenced to Greenwich).

When I perform a coordinate conversion (I have Erdas Imagine), I do obtain
meters (EN) but, while Northings appear to be of comparable values with
the ones deriving from my images, Eastings really depict another place on
Earth. Namely: a spot which I know the gross location of has the following
coords on the ascii file

LL: N42.5, E13, converted to:
EN: 4713135.411, 828703.211

The same gross spot on the image has the following EN:
4700125.563, 2406581..

Now, these eastings values are just _so_ much apart.. There's an order of
magnitude between then... Anybody has ideas? I tend to trust the
conversion routine..

Many thanks in advance and kindest regards,



Umberto Fracassi

---------------------------------------------------------------
Dip.to di Scienze della Terra
Universita' di Firenze
Via I. Nardi, 2
50132 Firenze
Italy

Tel:    +39-055-243486
Fax:    +39-055-241595
Email:  [log in to unmask]
WWW:    http://geosciences.org/umberto
---------------------------------------------------------------
--- End Forwarded Message ---