Read spherical harmonic coefficients from a JPL ascii-formatted file.
Usage
call SHReadJPL (filename, cilm, lmax, error, gm, formatstring, exitstatus)
Parameters
filename: input, character(*)- The filename of the JPL ascii formatted spherical harmonic coefficients.
cilm: output, real(dp), dimension (2,lmax+1,lmax+1)- The spherical harmonic coefficients contained in
filename. lmax: input, integer(int32)- The maximum spherical harmonic degree of
cilm. error: output, optional, real(dp), dimension (2,lmax+1,lmax+1)- The errors corresponding to the spherical harmonic coefficients
cilm. gm: output, optional, real(dp), dimension(2)- The mass-gravitational constant and error.
formatstring: input character(6), optional, default = “E19.12”- The format string used to read the elements of
cilmandcilm_error. The default is “E19.12”. exitstatus: output, optional, integer(int32)- If present, instead of executing a STOP when an error is encountered, the variable exitstatus will be returned describing the error. 0 = No errors; 1 = Improper dimensions of input array; 2 = Improper bounds for input variable; 3 = Error allocating memory; 4 = File IO error.
Description
SHReadJPL will read spherical harmonic coefficients from a JPL ascii formatted file into an array cilm. The maximum spherical harmonic degree lmax must be known a priori. The errors associated with the coefficients cilm will be read if the optional array error is specified. The real numbers are assumed to be formated with the specifier E19.12, but this can be changed by specifiying the optional string formatstring. If the optional parameter gm is specified, the mass-gravitational constant and error will be output, if present.
The JPL ascii formatted file is organized as follows:
- Comment lines starting with “#”.
gm(if a gravitational potential file)- A list of
J_l, which is-cilm(1,l+1,1). - A list of the cosine and sine terms.
- The errors of the above (starting at step 2).