[mapserver-users] Projection question - Australia

[Andrew.Loughhead at csiro.au]

My take on this:

AMG55 == UTM zone 55 projection on the AGD66 datum. 
(AMG meaning Australian Map Grid, AGD Australian Geodetic Datum). 

MGA55 == UTM zone 55 projection on the GDA94 datum. 
(MGA meaning Map Grid of Australia, GDA Geocentric Datum of Australia). 

GDA94 and WGS84 are apparently the same for most purposes.  

Note that if the flat file is correctly described, AMG must mean 
AGD66 datum.  

Anyway, to answer your question I think you need to use the Projection 
Utility that comes with Arcview 3.2 (NOT the 'projector' extension, 
Projection Utility is a standalone program).  This will do the 
datum conversion for you.  If you don't have Arcview there are other 
programs that will do it for you, I'm not familiar with PROJ4 but 
would be suprised if it can't do this.  

my AUD $0.04 worth, hth, 
Andrew

> -----Original Message-----
> From: Lyndon Zimmermann [mailto:lyndon.zimmermann at adelaide.edu.au]
> Sent: Thursday, 11 April 2002 10:21 AM
> To: Marie Flanagan
> Cc: mapserver-users at lists.gis.umn.edu
> Subject: Re: [mapserver-users] Projection question - Australia
> 
> 
> Marie,
> 
> I would say that the AMG Zone 55 you refer to is equivalent 
> to UTM Zone
> 55, so the various desktop packages should provide that translation. 
> ArcView and ArcTOOLBOX do.  There are other point by point conversion
> tools around.  Note the new GDA94 is close enough to WGS84 with a
> vertical translation.
> 
> Lyndon Z
> 
> 
> > Marie Flanagan wrote:
> > 
> > Hi all,
> > 
> > I have a question about projection.  My map data of the NSW area of
> > Australia uses WGS84 datum and spheroid.  Units are in geographic
> > Digital Degrees.  This looks fine when displayed in mapserver.
> > 
> > I also have a flat file of x,y co-ordinates from the AMG 
> zone 55 which
> > I want to overlay on the map.  I have managed to figure out how to
> > generate a shape file for this.  But I am now left with the question
> > of how to convert from AMG cartesian co-ords to WGS longitude and
> > latitude.  I think it may be possible to convert these using
> > PROJ4 before I create the shape file, but I am not sure if it's
> > possible to convert from AMG to WGS.
> > 
> > I will continue to search for PROJ4 examples to see if this is
> > possible but in the meantime if anyone could advise I would be most
> > grateful.  I am not a cartographer so excuse any obvious 
> ignorance in
> > the wording of my question!
> > 
> > Regards,
> > 
> > Marie
> 
> -- 
> Lyndon Zimmermann
> BE (Mech Adelaide) Grad Dip Bus Admin (UniSA)
> 
> LOW RAINFALL AGROFORESTRY RESEARCH UNIT
> PhD Researcher
> CRC for Plant-Based Management of Dryland Salinity
> 
> University of Adelaide Department of Agronomy and Farming Systems
> Physical address: Hannaford Building (via Gate 3) Waite Campus, South
> Australia
> Postal: Adelaide University, PMB1 Glen Osmond, SA 5064, Australia
> Dir (Soil and Water) +61-8-8303 6571 Mob 0414 91 4577
> Fax +61-8-8303 6717 email lyndon.zimmermann at adelaide.edu.au
> 
> Unless otherwise stated, the content of this message and 
> attachments may
> be forwarded or quoted, with due acknowledgement.  No 
> representation is
> made that this email is free of viruses. Virus scanning is recommended
> and is the responsibility of the recipient.
>