The "findbesttransform" web service provides meta data about a transform.

A typical URL is: http://myserver.mycompany.com:8080/INTGeoServer/json/findbesttransform?json= {"crsCode":"3467", "areaTop":"71.4", "areaLeft":"172.42", "areaBottom":"51.3", "areaRight":"-129.99"}

The following parameters are available:

crsCode: the CRS code for which a transform will be found. This is a required parameter.

areaTop: the northern latitude of the area of use. This is a required parameter.

areaLeft: the western longitude of the area of use. This is a required parameter.

areaBottom: the southern latitude of the area of use. This is a required parameter.

areaRight: the eastern longitude of the area of use. This is a required parameter.

Here is an example response. This response has been formatted to improve readability.

{

"transformCode":15931,

"transformName":"NAD83(NSRS2007) to WGS 84 (1)",

"sourceCrsCode":4759,

"targetCrsCode":4326,

"scope":"For applications to an accuracy of 1 metre.",

"remarks":"Approximation at the +/- 1m level assuming that NAD83(NSRS2007) is equivalent to WGS 84 within the accuracy of the transformation.",

"areaOfUse":"USA - CONUS and Alaska; PRVI",

"areaOfUseBBox":{

"northLat":74.71,

"southLat":14.92,

"westLon":167.65,

"eastLon":-63.88

},

"accuracyM":1.0,

"deprecated":false,

"towgs84":"TOWGS84[0.000000, 0.000000, 0.000000, 0, 0, 0, 0]",

"isEmpty":false

}

The transformCode entry is the code of the transform that best matches the CRS and area of use.

The transformName entry is the name of the transform matching that code.

The sourceCrsCode entry is the source CRS code for the transform that was requested.

The targetCrsCode entry is the target CRS code for the transform that was requested. This is usually 4326, which is WGS 84

The scope entry gives information about the transform and how it is used.

The remarks entry shows any additional remarks about the transform. Usually this is blank, however it can contain information such as the company that created it, the reason for creating it, etc.

The areaOfUse entry is a short description describing where the transform is used.

The areaOfUseBBox entry contains the following four entries which define the area of use in latitude and longitude values.

The northLat entry is the northern latitude for the area of use.

The southLat entry is the southern latitude for the area of use.

The westLon entry is the western longitude for the area of use.

The eastLon entry is the eastern longitude for the area of use.

The accuracyM entry is the accuracy in meters of the transform.

The deprecated entry is true if this transform has been deprecated for any number of reasons. It can be useful to examine deprecated transforms to see what changes have been made on the fixed version.

The towgs84 entry is the transformation to the WGS84 CRS if it exists.

The isEmpty entry true or false depending on if the transform is empty or not.