Can you provide a link or instructions for setting the parameters in proj4Projection.InternalProjectionParametersString?
In particular, I am looking to setup a projection for Polk County Wisconsin. All of Wisconsin appears to use custom projections. The projection values from OSGEO.ORG are as follows:
CS_NAME: PolkWI-IF DESC_NM: Wisconsin County Systems: Polk County, International Foot GROUP: OTHR-US SOURCE: Wisconsin Coordinate Systems, State Cartographer's Office DT_NAME: HPGN PROJ: TM-WCCS UNIT: IFOOT PARM1: -92.6333333333 PARM2: -28.1300 PARM3: 1000.0033 SCL_RED: 1.00000000 ORG_LAT: 44.6611111111 X_OFF: 465000.9298 Y_OFF: 0.0000
There are some Proj4 SRID and ParameterString information in the folder C:\Program Files\ThinkGeo\Map Suite Desktop Full Edition 3.0 (BETA)\Documentation\Projections, you can try to search the Proj4 ParameterString from those projection files. I know there are some projections related with Wisconsin.
Is there nothing that shows the possible variables and values in the projection string? I would think there must be documentation somewhere, even if it is at the original source.
I have a look into this but with on luck. We have foud some projection ParameterString related with “Wisconsin” in “C:\Program Files\ThinkGeo\Map Suite Desktop Full Edition 3.0 (BETA)\Documentation\Projections\” EPSG.rtf, ESRI.extra.rtf ESRI.rtf, NAD27.rtf NAD83.rtf
But seems none of them is identical with yours. We will spend more time on this and let you know what we find out. By the way, could you please let me know where do you find that projection information in OSGEO.ORG?
I looked at the documentation for Wisconsin County Coordinate System sco.wisc.edu/wiscoord/county.php Unfortunately, it does not explain about the different parameters found in the link you gave us. We provide the tools with Proj4 for any projection needs. Now, you will need to contact the authorities of Winsconsin County Coordinate System for the specific info on their system. I think that you would need to contact sco.wisc.edu/about/Contact.php or email at sco@mailplus.wisc.edu.
I’m not sure you understood the original question. Although I am interested in Polk County for the current project, I need to understand the projection string.
Can you provide a link or instructions for setting the parameters in proj4Projection.InternalProjectionParametersString?
The projection starts off with +proj= which is the projection name. I have seen longlat and tmerc. Are there others? The entry +ellps is self explanatory, but what ellipsoids are handled. +units is also fairly obvious but are there other settings that m and f? What about survey feet? What exactly are +lat and +lon? I assume they are the center latitude and longitude, but that is not obvious. After this there can be any number of entries including +k, +x_0, +y_0, +no_def. What do these mean and what are the possible entries?
We did some investigation on TM-WCCS projection but there is so little information about it. Instead we did find how to create a Transverse Mercator(TM) PROJ4 parameter string from link: remotesensing.org/geotif...cator.html
As I know TM-WCCS is a variation of the traditional version of the Transverse Mercator projection, there are some minor differences between TM-WCCS and TM which you can find from: docs.safe.com/fme/html/Coord..._types.htm
I tried to create a PolkWI-IF parameter string by referencing above pages:
Two things I am not very sure are about the parameter +lon_0 and the unit.
The TM-WCCSS projection does not have the ORG_LNG parameter, so I tried to use 0 instead.
The units supported by proj4 are Meters, US survey feet, etc, but PolkWI-IF projection’s unit is IFOOT so I tried to use meter instead, and the value is referenced from a parameter string in proj4 documentation for Wisconsin Central.
The default projection system we use is Proj4, which is probably the most used projection engine out there. I highly suggest that since what you are looking for is a Proj4 projection string that you can post on the forum below. We are familiar with Proj4 however we don’t claim to be experts in it.