GPSMeter PDA

Using US State Plane projections.

We can read from http://gpsinformation.net/state-plane.html site that:

During the 1930s, the U.S. Coast and Geodetic Survey (USC&GS), now NGS developed the State Plane Coordinate System which have been very popular at the local level. Many users find State Plane maps more adaptable than UTMs because the zone boundaries fall along political lines (e.g., State and County) as opposed to geometric lines. In addition, there is less "scale reduction" with State Planes when compared to UTMs, and distances are some four times as accurate.. The State Plane systems are typically the standard of the various state agencies such as DOT, OSM, TVA, etc., and are commonly used throughout the engineering and surveying fields. Standards for The State Plane Coordinate System of 1983 can be found at: http://www.ngs.noaa.gov/PUBS_LIB/ManualNOSNGS5.pdf



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There are almost three ways to set a State Plane coordinate system in GPSMeter PDA.

1) Using the corresponding EPSG code. (Note that this method is also valid for any projection by knowing their EPSG code.)

This it's probably the most safe and powerful way. Find the EPSG code searching in the site http://spatialreference.org/ref/
There are over 100 State Plane projections defined. We will use, for instance, the search for "Washington State Plane" (http://spatialreference.org/ref/?search=Washington+State+Plane&srtext=Search) will have the following result:



SR-ORG:110: NAD_1983_HARN_StatePlane_Washington_North_FIPS_4601_Feet ESRI:102348: NAD 1983 HARN StatePlane Washington North FIPS 4601 ESRI:102349: NAD 1983 HARN StatePlane Washington South FIPS 4602 ESRI:102748: NAD 1983 StatePlane Washington North FIPS 4601 Feet ESRI:102749: NAD 1983 StatePlane Washington South FIPS 4602 Feet

You can ignore the SR-ORG value, we are only interested into the ESRI numbers.

Then, in GPSMeter PDA, go to "Settings" menu and press "Other projections" inside the tab "Coord" and then press "Config". I will use "ESRI:102748: NAD 1983 StatePlane Washington North FIPS 4601 Feet" so that write something in "Name" as "Washington StatePlane N ft", choose "EPSG Code" and write 102748. Press Ok. Goto "Datum" tab and choose "NAR NA 1983 US - CONUS" and press Ok. All is done.


If you prefers to use the same projection (StatePlane Washington North) but using meters for the X/Y coordinates then use 102348 instead.


The program will shown automatically the units of projection choosen (meters, International feet, US Survey feet). If you want to know the units of projection using the above page, click in a result of above and then click in "Well Known Text as HTML", you will see the unit at the field "UNIT["Meter",1] of PROJECTION group

PROJCS["NAD_1983_HARN_StatePlane_Washington_North_FIPS_4601",
    GEOGCS["GCS_North_American_1983_HARN",

        DATUM["NAD83_High_Accuracy_Regional_Network",
            SPHEROID["GRS_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],

        UNIT["Degree",0.017453292519943295]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["False_Easting",500000],

    PARAMETER["False_Northing",0],
    PARAMETER["Central_Meridian",-120.8333333333333],
    PARAMETER["Standard_Parallel_1",47.5],

    PARAMETER["Standard_Parallel_2",48.73333333333333],
    PARAMETER["Latitude_Of_Origin",47],
    UNIT["Meter",1],

    AUTHORITY["EPSG","102348"]]


And for this the unit is Foot_US (US Survey foot)


PROJCS["NAD_1983_StatePlane_Washington_North_FIPS_4601_Feet",
    GEOGCS["GCS_North_American_1983",

        DATUM["North_American_Datum_1983",
            SPHEROID["GRS_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],

        UNIT["Degree",0.017453292519943295]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["False_Easting",1640416.666666667],

    PARAMETER["False_Northing",0],
    PARAMETER["Central_Meridian",-120.8333333333333],
    PARAMETER["Standard_Parallel_1",47.5],

    PARAMETER["Standard_Parallel_2",48.73333333333333],
    PARAMETER["Latitude_Of_Origin",47],
    UNIT["Foot_US",0.30480060960121924],

    AUTHORITY["EPSG","102748"]]

There are still two ways more, however, will only work in meters in the current version.

2) Using the zone number for the State Plane projection.

If you know the identifier number for the State Plane projection you can type directly by choosing the type of projection "State Plane". However this will choose the meter-based variant, in the current version. If you want to use Foot or US Survey Foot use method 1. Indeed, you can see this identifier number in the above links (4601 for StatePlane Washington North)

3) Using the raw specification.

Using the returned values

PROJCS["NAD_1983_HARN_StatePlane_Washington_North_FIPS_4601",
    GEOGCS["GCS_North_American_1983_HARN",

        DATUM["NAD83_High_Accuracy_Regional_Network",
            SPHEROID["GRS_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],

        UNIT["Degree",0.017453292519943295]],
    PROJECTION["Lambert_Conformal_Conic_2SP"],
    PARAMETER["False_Easting",500000],

    PARAMETER["False_Northing",0],
    PARAMETER["Central_Meridian",-120.8333333333333],
    PARAMETER["Standard_Parallel_1",47.5],

    PARAMETER["Standard_Parallel_2",48.73333333333333],
    PARAMETER["Latitude_Of_Origin",47],
    UNIT["Meter",1],

    AUTHORITY["EPSG","102348"]]

or using your own custom set, you can specify practically any projection. For example, in this case type the values for the "Lambert_Conformal_Conic_2SP" type projection. Again, for the current version, only meters can be used as units. If you want to use Foot or US Survey Foot use method 1.

Testing the projection.

Simply, type a WPT and see their PROJ values.