Skip to content

Improve WGS84 displacement functions #127

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
MartinSollie wants to merge 1 commit into
base: develop
Choose a base branch
from
Open

Improve WGS84 displacement functions #127

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 9 additions & 7 deletions src/java/pt/lsts/neptus/types/coord/CoordinateUtil.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1249,7 +1249,7 @@ public static double[] WGS84displacement(double latDegrees1, double lonDegrees1,

ret[0] = -slat * clon * ox - slat * slon * oy + clat * oz; // North
ret[1] = -slon * ox + clon * oy; // East
ret[2] = depth1 - depth2;
ret[2] = -clat * clon * ox - clat * slon * oy - slat * oz; // Down

return ret;
}
Expand All @@ -1267,7 +1267,12 @@ public static double[] WGS84displace(double latDegrees, double lonDegrees, doubl
double[] xyz = toECEF(latDegrees, lonDegrees, depth);
double[] lld = {latDegrees, lonDegrees, depth };
// Compute Geocentric latitude
double phi = Math.atan2(xyz[2], Math.sqrt(xyz[0] * xyz[0] + xyz[1] * xyz[1]));
double c_wgs84_a = 6378137.0;
double c_wgs84_e2 = 0.00669437999013;
double p = Math.sqrt(xyz[0] * xyz[0] + xyz[1] * xyz[1]);
double lat_sin = Math.sin(Math.toRadians(lld[1]));
double ell_N = c_wgs84_a / Math.sqrt(1 - c_wgs84_e2 * (lat_sin * lat_sin));
double phi = Math.atan2(xyz[2],p*(1 - c_wgs84_e2 * ell_N / (ell_N - depth)));

// Compute all needed sine and cosine terms for conversion.
double slon = Math.sin(Math.toRadians(lld[1]));
Expand All @@ -1284,11 +1289,8 @@ public static double[] WGS84displace(double latDegrees, double lonDegrees, doubl

// Convert back to WGS-84 coordinates
lld = toGeodetic(xyz[0], xyz[1], xyz[2]);

if (d != 0d)
lld[2] = depth + d;
else
lld[2] = depth;

lld[2] = -lld[2];
return lld;
}

Expand Down