sh2xyz : Forward calculation of topographic or gravitational data using spherical harmonic coefficients.
Installation
You need to compile the executable file sh2xyz
using the makefile
. Please change the variable CC
in the makefile
to the compiler you use. Parallel computing is enable using the -fopenmp
flag, delete it if you don’t want the parallel computing.
CC = g++-8 -fopenmp
If you don’t have gcc
installed.
- For Mac OS users, install
gcc
using Homebrew by
brew install gcc
- For Linux users, install
gcc
by
apt-get install gcc
After the gcc
is installed. Use make
the compile the program. Then move or symlink the executable file sh2xyz
to any directory included in your $PATH, for instance, /usr/local/bin
.
Usage
sph2xyz -t<table> -r<lonmin>/<lonmax>/<latmin>/<latmax>[/<altitude>] -i<dlon>/<dlat> -d<type> -f<ln>/<lm>/<hn>/<hm> [-p<loc-file>] [-s<refr>/<refR>] [-g<GM>/<R>] [-n<type>] [-c<col1>,<col2>,<col3>,<col4>] [-z<alti-file>[+d<col1>,<col2>,<col3>]] [-h] > out-file
Options
- -t: Input filename of the coefficients.
- -r: Initialize the range of observation points. Altitude of the points is optional (will be 0 if no set).
- -i: Intervals of the observation points.
- -d: Types of forward calculation.
- -f: Starting and ending order/degree that will be used for calculation.
- -p: Interpolate the forward calculated data to spherical locations read from the file.
- -s: short and long semi-radius of the reference coordinate system.
- -g: Model parameters of gravity models. This option must be set if we are calculating gravitational data.
- -n: Normalization type of the Associated Legendre Function.
- -c: Select input columns of the coefficients.
- -z: Initialize the observation’s altitudes from the a input file.
- -h: Show help information.
Examples
To forward calculating an example.SHcoeffs
which maximal degree/order are both 360.
sh2xyz -t example.SHcoeffs -r -180/180/-90/90/0 -i 0.5/0.5 -f 0/0/360/360 -s 10000/10000 > example.txt
The calculated data is shown as below: