Just thought to share.

[RPGIS]

Hi,

I found this code that I copied from copilot and modified for my specific needs and works exactly as needed. Just thought to share if anyone is interested.

// Constants for NAD83 Georgia West (FIPS 1002)
var A = 6378137.0; // Semi-major axis for NAD83
var F = 1 / 298.257222101; // Flattening for NAD83
var E2 = (2 * F) - (F * F); // Eccentricity squared
var centralMeridian = -84.16666666666667 * (PI / 180); // Central meridian for Georgia West (degrees to radians)
var latitudeOfOrigin = 30.0 // Latitude of origin (degrees to radians)
var scaleFactor = 0.9999; // Scale factor
var falseEasting = 2296583.333333 * 0.3048006096012192; // False easting in meters (1 US foot = 0.3048006096012192 meters)
var falseNorthing = 0.0; // False northing in meters

// Function to convert State Plane (NAD83) to Latitude and Longitude
function statePlaneToLatLong(x, y) {
    x *= 0.3048006096012192; // Convert x from US Feet to meters
    y *= 0.3048006096012192; // Convert y from US Feet to meters
    x -= falseEasting;
    y -= falseNorthing;

    var m = y / scaleFactor;
    var mu = m / (A * (1 - (E2 / 4) - (3 * E2 * E2 / 64) - (5 * E2 * E2 * E2 / 256)));

    var e1 = (1 - sqrt(1 - E2)) / (1 + sqrt(1 - E2));
    
    var phi1 = mu + (3 * e1 / 2 - 27 * pow(e1, 3) / 32) * sin(2 * mu)
        + (21 * pow(e1, 2) / 16 - 55 * pow(e1, 4) / 32) * sin(4 * mu)
        + (151 * pow(e1, 3) / 96) * sin(6 * mu)
        + (1097 * pow(e1, 4) / 512) * sin(8 * mu);

    var sinPhi1 = sin(phi1);
    var cosPhi1 = cos(phi1);
    var t1 = tan(phi1) * tan(phi1);
    var c1 = E2 * cosPhi1 * cosPhi1 / (1 - E2);
    var r1 = A * (1 - E2) / pow(1 - E2 * sinPhi1 * sinPhi1, 1.5);
    var n1 = A / sqrt(1 - E2 * sinPhi1 * sinPhi1);
    var d = x / (n1 * scaleFactor);

    // Calculate latitude and longitude in radians
    var latitude = phi1 - (n1 * tan(phi1) / r1)
        * (d * d / 2 - (5 + 3 * t1 + 10 * c1 - 4 * c1 * c1 - 9 * E2) * pow(d, 4) / 24
        + (61 + 90 * t1 + 298 * c1 + 45 * t1 * t1 - 252 * E2 - 3 * c1 * c1) * pow(d, 6) / 720);

    var longitude = centralMeridian + (d - (1 + 2 * t1 + c1) * pow(d, 3) / 6
        + (5 - 2 * c1 + 28 * t1 - 3 * c1 * c1 + 8 * E2 + 24 * t1 * t1) * pow(d, 5) / 120) / cosPhi1;

    // Convert latitude and longitude to degrees
    var latitudeDeg = latitude * (180 / PI)*10;
    var longitudeDeg = longitude * (180 / PI);

    // Format results as degrees North and degrees West
    return {
        latitude: round( abs(latitudeDeg) , 6),
        longitude: round( abs(longitudeDeg) , 6)
    };
}

// Example usage with provided coordinates
var x = Geometry($feature).x; // X coordinate in US feet
var y = Geometry($feature).y; // Y coordinate in US feet

var result = statePlaneToLatLong(x, y);
console(result); // Output: {latitude: "xy.xyzxyz° N", longitude: "xy.xyzxyz° W"}
return result.latitude

[LindsayRaabe_FPCWA]

Can I suggest adding the purpose of the code to the post heading to make it more searchable? I believe it's a Lat/Long conversion code, which I know a lot of people would be looking for. Also maybe add some tags to improve search results.