EPSG code for...
Dean C. Mikkelsen
dcmikkelsen at SHAW.CA
Sat Jun 11 03:00:20 EDT 2005
Hi Chris,
Take a look at the following web-page.
I am leaning towards a problem now in defining which State Plane
Co-ordinate System is being used. i.e. one of the ones we are using is
wrong - we may actually be north or south of the current one. Now the
trick is to determine which one. A note to other readers epsg:4326 is
WGS84.
Did you try reprojecting the NAD27 Layer with the NAD83 definition? Or
with epsg:4326? What happens?
Also a note, once we determine which projection and datum, we should
report it back to the data provider with notes that metadata such as
datum, SPCS (projection), etc. should be included in all datasets they
deliver.
I found a web-page that explains some of my logic and the numbers
appearing on your image (the large differences between the left and
right images) - though a different state.
Please see:
http://www.wadetrim.com/resources/articles/sblocks.htm
Kind regards,
Dean
-----Original Message-----
From: Christopher R. Thorne [mailto:christhorne at sympatico.ca]
Sent: Friday, June 10, 2005 2:10 PM
To: Dean C. Mikkelsen
Cc: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] EPSG code for...
Dave,
Thanks for all your help i feel we are either very closer or this is
really bad data??
I tried the these epsg codes and well see image. NAD83 layer is to the
left and NAD27 layer is to the right. I had to find the layer by
converting the map output to espg:4326 Lat/Long.
What do you make of it?
Chris
Dean C. Mikkelsen wrote:
> Hi Chris,
>
> If we give SPCS a try, we can use the following:
>
> # 405: california v: nad83
> <405> proj=lcc datum=NAD83
> lon_0=-118 lat_1=35d28 lat_2=34d2 lat_0=33d30
> x_0=2000000 y_0=500000
> no_defs <>
>
> For NAD83
>
> And for NAD27 we can use the following:
>
> # 407: california vii: nad27
> <407> proj=lcc datum=NAD27
> lon_0=-118d20 lat_1=34d25 lat_2=33d52 lat_0=34d8 x_0=1276106.450596901
> y_0=1268253.006858014 no_defs <>
>
> Note the change in Zones. Los Angeles County was in CALIFORNIA ZONE
> VII. ZONE VII was eliminated for NAD83 with Los Angeles County being
> included with ZONE V.
>
> This should hopefully solve the shift problem you are seeing. I would
> aim towards the NAD27 variant for the original projection being
> defined and then aim at projecting out in NAD83.
>
> Let me know what happens.
>
> Cheers,
> Dean
>
> Consultant, Terra ETL Ltd.
> North Vancouver, BC
> Canada
> Phone: +1 604 929 8630
> E-mail: dcmikkelsen at shaw.ca
>
>
>
>
> -----Original Message-----
> From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]
> On Behalf Of Christopher R. Thorne
> Sent: Wednesday, June 08, 2005 11:35 AM
> To: MAPSERVER-USERS at LISTS.UMN.EDU
> Subject: Re: [UMN_MAPSERVER-USERS] EPSG code for...
>
>
> I was worried about that ;) Unfortunately, it is not an easy thing to
> pin point what the projection actually is.
>
> Thanks again,
> Chris
>
> Dean C. Mikkelsen wrote:
>
>>Hi Ken,
>>
>>Thanks for the information.
>>
>>The other problem I was looking at is that it may be a State Plane
>>Coordinate System as well.
>>
>>California is divided into many zones and the dataset being worked
>>with
>>did not include some of the projection information.
>>
>>Cheers,
>>Dean
>>
>>Consultant, Terra ETL Ltd.
>>North Vancouver, BC
>>Canada
>>Phone: +1 604 929 8630
>>E-mail: dcmikkelsen at shaw.ca <mailto:dcmikkelsen at shaw.ca>
>>
>> -----Original Message-----
>> *From:* UMN MapServer Users List
>> [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] *On Behalf Of *Ken Lord
>> *Sent:* Tuesday, June 07, 2005 12:44 PM
>> *To:* MAPSERVER-USERS at LISTS.UMN.EDU
>> *Subject:* Re: [UMN_MAPSERVER-USERS] EPSG code for...
>>
>> Dean,
>>
>> Make sure you have the Proj software installed, there's
>
> information
>
>> about it here:
>>
>> http://www.maptools.org/maplab/index.phtml?page=maplab_windows.txt
>>
>> and here:
>>
>> http://www.remotesensing.org/proj/
>> <http://proj.maptools.org/>
>> If you haven't already, grab the windows binaries, unzip and place
>> the Proj folder on your C drive.
>>
>> C:/Proj
>>
>> Cheers,
>> Ken Lord
>> Vancouver BC
>>
>>
>>
>>
>> On 6/7/05, *Christopher R. Thorne* <christhorne at sympatico.ca
>> <mailto:christhorne at sympatico.ca>> wrote:
>>
>> Dean C. Mikkelsen wrote:
>> > Hi Chris,
>> >
>> > It may be a directory problem, MapServer is not reading the
>> CONUS or
>> > NAD27/NAD83 files correctly in the proj directory.
>> >
>> > Are you using the MS4W or a later version of MapServer?
>>
>> I am using the latest version of ms4w, with Chameleon using
>> MapServer 4.4.2
>>
>> Any suggestions?
>>
>> >
>> > Cheers,
>> > Dean
>> >
>> > Dean C. Mikkelsen, B.Sc.,P.Eng.
>> > Consultant, Terra ETL Ltd.
>> > North Vancouver, BC
>> > Canada
>> > Phone: +1 604 929 8630
>> > E-mail: dcmikkelsen at shaw.ca <mailto:dcmikkelsen at shaw.ca>
>> >
>> >
>> >
>> > -----Original Message-----
>> > From: Christopher R. Thorne
>
> [mailto:christhorne at sympatico.ca
>
>> <mailto:christhorne at sympatico.ca>]
>> > Sent: Monday, June 06, 2005 4:10 PM
>> > To: Dean C. Mikkelsen
>> > Cc: MAPSERVER-USERS at LISTS.UMN.EDU
>> <mailto:MAPSERVER-USERS at LISTS.UMN.EDU>
>> > Subject: Re: [UMN_MAPSERVER-USERS] EPSG code for...
>> >
>> >
>> > Yes I used these projections where
>> >
>> > 26911 NAD 83 is the projection of the mapfile and where
>
> NAD27
>
>> <26711> is
>> >
>> > being reprojected.
>> >
>> > See first attached image to see how messed up the Nad27
>
> layer
>
>> gets.
>> >
>> > If I don't define projection you can see the a shift
>
> between
>
>> the line
>> > layer and the solid polygon layers.
>> >
>> > Comments/suggestions??
>> >
>> > Thanks
>> > Chris
>> >
>> > Dean C. Mikkelsen wrote:
>> >
>> >>Hi Chris,
>> >>
>> >>Did you try the following?
>> >>
>> >># NAD27 / UTM zone 11N
>> >><26711> +proj=utm +zone=11 +ellps=clrk66 +datum=NAD27
>
> +units=m
>
>> >>no_defs <>
>> >>
>> >># NAD83 / UTM zone 11N
>> >><26911> +proj=utm +zone=11 +ellps=GRS80 +datum=NAD83
>> +units=m no_defs
>> >
>> >
>> >><>
>> >>
>> >>Cheers,
>> >>Dean
>> >>
>> >>Dean C. Mikkelsen, B.Sc.,P.Eng.
>> >>Consultant, Terra ETL Ltd.
>> >>North Vancouver, BC
>> >>Canada
>> >>Phone: +1 604 929 8630
>> >>E-mail: dcmikkelsen at shaw.ca <mailto:dcmikkelsen at shaw.ca>
>> >>
>> >>
>> >>
>> >>-----Original Message-----
>> >>From: UMN MapServer Users List
>> [mailto:MAPSERVER-USERS at LISTS.UMN.EDU
>> <mailto:MAPSERVER-USERS at LISTS.UMN.EDU>]
>> >>On Behalf Of Christopher R. Thorne
>> >>Sent: Monday, June 06, 2005 3:29 PM
>> >>To: MAPSERVER-USERS at LISTS.UMN.EDU
>> <mailto:MAPSERVER-USERS at LISTS.UMN.EDU>
>> >>Subject: [UMN_MAPSERVER-USERS] EPSG code for...
>> >>
>> >>
>> >>Hello all,
>> >>
>> >>If you were given the following information for two
>> projections for
>> >>California LA County region.
>> >>
>> >>
>> >>NAD83 UTM Zone 11 meters
>> >>
>> >>NAD27 UTM Zone 11 meters
>> >>
>> >>What would be your suggested codes? I have tried a few but
>> can not
>> >>seem
>> >>to get it.
>> >>
>> >>Thanks
>> >>Chris
>> >>
>> >>
>> >
>> >
>> >
>>
>>
>> --
>> Christopher R. Thorne, GIS Specialist
>> --
>> 3406 Southgate Rd. Ottawa ON K1V 9P9
>> christhorne at sympatico.ca <mailto:christhorne at sympatico.ca>
>> Tel:(613)523-6593
>
>
>
--
Christopher R. Thorne, GIS Specialist
--
3406 Southgate Rd. Ottawa ON K1V 9P9
christhorne at sympatico.ca
Tel:(613)523-6593
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