Hi guys, I would like to know if anyone knows how I can calculate the analytical signal to highlight edges and tilt derivate as filters in some anomaly map, for example in this free air anomaly map earthfaa3m.grd, I would greatly appreciate the help!

Not near my text books and cannot recall definition of analytical signal for a 2-D faa grid. Might involve an FFT and some algebra? If so, you may ber able to compute it via **grdfft** and **grdmath**? If you have an equation we maybe able to comment more, but guessing @WHFSmith knows this stuff.

Of course, I forgot to put them in, these are the equations, the TRD is the tilt derivative and AS is for the analytical signal.

Thanks!

What I don’t understand is how to manipulate those equations, because I can calculate those derivatives that come out with grdfft -D or -A depending on the direction, so I use those grids resulting from the derivatives and make the equations with grdmath?

Some 30 y ago, still in my Fortran times I think, I played around with the analytical signal but have only faint memories of it. What I remember is that it was very at fashion at the time but fade down because the results were poorly satisfactory for real cases and the method suffered a lot from non-uniqueness.

And yes, you can try to used grdmath to compute that equation.