HPGN Datum? (fwd)

[Dean C. Mikkelsen]

Hi Didrik,

In the epsg file, for NTF II, I get the following:

# NTF (Paris) / France II
# Unable to translate coordinate system into PROJ.4 format.

I could not find your code 27572.

Let me suggest a work-around. It may not be popular, but it should solve
the problem for you. 

In the epsg file, add the following line of code:

<27572> +proj=lcc +lat_0=18.000000000 +lon_0=-77.000000000 +k=0.99987742
+x_0=600000  +y_0=2200000 +ellps=clrk66  +towgs84=-168,-60,320,0,0,0,0
+units=m  no_defs <>

This should resolve the problem.

Let me know what happens.

Kind regards,
Dean


Dean C. Mikkelsen,B.Sc.,P.Eng.
Principal Consultant
Terra ETL Ltd. - Consultants on GIS & Geodesy
Vancouver, B.C., Canada
Phone: 604-929-8630
E-mail: dcmikkelsen at shaw.ca


-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Didrik Pinte
Sent: April 26, 2005 12:06 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] HPGN Datum? (fwd)

Le mardi 26 avril 2005 à 08:22 +0200, Didrik Pinte a écrit :
> Le lundi 25 avril 2005 à 23:00 -0400, Frank Warmerdam a écrit :
> > In any event, if you error is on the order of 100m then the
> > problem is likely not the false northing being off by 350000
> > (meters or feet).  That level of error is mostly likely related to
> > the datum shifting not being applied or possibly a mixup between
> > different kinds of feet.   I am doubtful it is related to HPGN since
> > my understanding is that the difference between NAD83 and HPGN
> > is small (less than 5 meters say), though I am not too sure about
that
> > part. 
> 
> I did not follow all the thread but it seems I have the same problem
> here.
> 
> I have a layer with rasters in epsg:27572 (France NTF II) and some GPS
> points in WGS84. The error in reprojection of the points to epsg:27572
> is less than 100 meters. 
> 
> I really don't know how to solve this but there must be a solution.
> 
> Didrik

Here is the related .map file (without symbol definition and all the
rasters)

MAP
        IMAGETYPE PNG24
        DEBUG ON
        EXTENT 347839 1.7954e+06 402109 1.83667e+06

        IMAGECOLOR 255 255 255
        SIZE 500 300
        STATUS ON
        SHAPEPATH "/var/www/mapserver/maps"
        RESOLUTION 81.28

        PROJECTION
               "init=epsg:27572"             
        END
        OUTPUTFORMAT
                NAME png24
                DRIVER "GD/PNG"
                MIMETYPE "image/png"
                IMAGEMODE PC256
                EXTENSION "png"
                FORMATOPTION "INTERLACE=OFF"
        END
        WEB
                LOG "/tmp/mapserver.log"
                IMAGEPATH "/var/www/mapserver/tmp/"
                IMAGEURL  "/tmp/"
                #Template file used for the base map
                TEMPLATE "templates/followap.html"
                #Header of the query window
                HEADER "templates/header.html"
                #Template used if nothing is found in the query
                EMPTY "../mapserver/templates/empty.html"
        END
        LAYER
                NAME "europe"
                DATA "shape/europe3.shp"
                STATUS DEFAULT
                TYPE POLYGON

                CLASS
                        COLOR 255 255 255
                        OUTLINECOLOR 0 0 0
                END
                PROJECTION
                        "init=epsg:27572"
                END
        END

        LAYER
                NAME "Regions"
                DATA "shape/franceNTF_France2.shp"
                STATUS DEFAULT
                TYPE POLYGON

                CLASS
                        COLOR 255 255 255
                        OUTLINECOLOR 0 0 0
                END
                PROJECTION
                        "init=epsg:27572"
                END
        END
        LAYER
                NAME "moved"               
                CONNECTION "user=postgres password=***** dbname=test
host=localhost port=5432"
                CONNECTIONTYPE postgis
                DATA "the_geom from gpsdata"
                STATUS ON
                TYPE POINT
                DEBUG ON

                TOLERANCE 5

                TEMPLATE "templates/filling.html"

                CLASS
                        NAME "Objet récemment déplacées"
                        EXPRESSION ([moved] >= 1)
                        COLOR 255 0 0
                        OUTLINECOLOR 255 0 0
                        SIZE 10
                        SYMBOL "circle"
                END
                CLASS
                        NAME "Objet non déplacées"
                        EXPRESSION ([moved] < 1)
                        COLOR 0 255 0
                        OUTLINECOLOR 0 255 0
                        SIZE 10
                        SYMBOL "circle"
                END

                PROJECTION
                        "init=epsg:4326"                       
                END
        END

        LAYER