NAME

cornymmik - calculates revised cutoff rigidity due to Nymmik et al

USAGE

cornymmik infile outfile corcol kpcol localtimecol

DESCRIPTION

cornymmik calculates a revised or corrected cut off rigidity (COR) value as described by Nymmik et al. 2009 (Nymmik hereafter). This method accounts for geomagnetic disturbances that are not handled by typical COR values calculated by static magnetic field maps (such as by prefilter).

The Nymmik technique uses the geomagnetic planetary Kp index as a proxy for geomagnetic disturbances. It assumes the Tsyganenko-89 geomagnetic disturbance model, which is parameterized by Kp. The research paper does full particle tracing in the geomagnetosphere. Since the geomagnetic model depends on local solar time, the results depend on local time as well. The result of the Nymmik work is an easily parameterized model for an adjusted cut off rigidity value.

The input must be a FITS binary table, which contains the following columns

While the inputs described above are listed as "column names," in fact any compatible CFITSIO calculator expression can be used. For example, localtimecol="LOCAL_TIME" would indicate to use the column named "LOCAL_TIME", but localtimecol="(LOCAL_TIME_HOURS*15)" would indicate to use an on-the-fly calculated expression which is 15 multiplied by the local time in hours (to get the required degrees).

The output is stored in a column named by the parameter outcol, which defaults to "COR_NYM".

The output file may be a new FITS file, or if outfile=INFILE, the input file will be replaced with the revised table (assuming clobber=YES).

PARAMETERS

infile [filename]
Name of the input file containing the required columns.
outfile [filename]
Name of the output file, where the revised input table is to be placed. If outfile=INFILE then the input file is modified in place. NOTE that if the requested column name is already present in the output, then it will not be deleted, and instead the quantities in that column will be adjusted.
corcol [string]
Name of the input COR column, or suitable CFITSIO calculator expression, as described above.
kpcol [string]
Name of the input Kp column, or suitable CFITSIO calculator expression, as described above.
localtimecol [string]
Name of the input local time column, or suitable CFITSIO calculator expression, as described above.
(outcol = "COR_NYM") [string]
Name of the output revised COR column, or suitable CFITSIO calculator expression, as described above.
(cleanup=YES) [boolean]
If YES, then clean up temporary files. If NO, then temporary files are preserved.
(clobber = NO) [boolean]
If outname already exists, then "clobber = yes" will overwrite it.
(history = yes) [boolean]
If set, HISTORY keywords are written to output.
(chatter = 1) [integer, 0 - 5]
Controls the amount of informative text written to standard output. Setting chatter = 5 will produce detailed diagnostic output, otherwise this task normally does not write any output.

EXAMPLES

1. Execute cornymmik prompting the user for parameter values.

	cornymmik

2. Execute cornymmik on filter.mkf, modifying in place.

	cornymmik filter.mkf INFILE COR_SAX KP LOCAL_TIME clobber=YES

SEE ALSO

LAST MODIFIED

December 2020

REFERENCES