Wrong comment in measurement code
The following code is taken from AngularAzEL
// Partial derivatives of azimuth/elevation with respect to state
// (beware element at index 0 is the value, not a derivative)
final double[] azDerivatives = azimuth.getGradient();
final double[] elDerivatives = elevation.getGradient();
estimated.setStateDerivatives(0,
Arrays.copyOfRange(azDerivatives, 0, 6), Arrays.copyOfRange(elDerivatives, 0, 6));
The comment is correct for DerivativeStructure, not Gradient. When perfoming the switch, some comments were forgotten.