make_grid

Syntax

make_grid --help
make_grid [options] fitacfname [inxname]
make_grid -old [options] fitname [inxname]
make_grid -cfit [options] cfitname
make_grid -cfit -old [options] cfitname
make_grid [options] fitacfnames...
make_grid -old [options] fitnames...
make_grid -cfit [options] cfitnames...
make_grid -cfit -old [options] cfitnames...

Synopsis

Creates a grid format file for a single radar site from either a fit, fitacf or cfit format file.

Options

`--help`	print the help message and exit.
`--version`	print the RST version number and exit.
`-vb`	verbose. Log information to the console.
`-sd yyyymmdd`	start from the date yyyymmdd.
`-st hr:mn`	start from the time hr:mn.
`-ed yyyymmdd`	stop at the date yyyymmdd.
`-et hr:mn`	stop at the time hr:mn.
`-ex hr:mn`	use the interval whose extent is hr:mn.
`-tl tlen`	ignore the scan flag and instead use a fixed length scan of tlen seconds.
`-i intt`	integrate the grid data into records of length intt seconds.
`-cn channel`	process data from channel channel for stereo mode data.
`-cn_fix channel`	manually set channel information written to output file.
`-ebm ebeams`	exclude the beams listed in ebeams, which is a comma separated list of beam numbers.
`-minrng minrange`	exclude data from range gates lower than minrange.
`-maxrng maxrange`	exclude data from range gates higher than maxrange.
`-minsrng minsrange`	exclude data from slant ranges lower than minsrange km (this takes precedence over minrng/maxrng).
`-maxsrng maxsrange`	exclude data from slant ranges higher than maxsrange km (this takes precedence over minrng/maxrng).
`-fwgt mode`	set the filter weighting mode to mode.
`-pmax pmax`	exclude data with a power greater than pmax dB.
`-vmax vmax`	exclude data with an absolute velocity greater than vmax m/s.
`-wmax wmax`	exclude data with a spectral width greater than wmax m/s.
`-vemax vemax`	exclude data with a velocity error greater than vemax m/s.
`-pmin pmin`	exclude data with a power less than pmin dB.
`-vmin vmin`	exclude data with an absolute velocity less than vmin m/s.
`-wmin wmin`	exclude data with a spectral width less than wmin m/s.
`-vemin vemin`	exclude data with a velocity error less than vemin m/s.
`-fmax fmax`	set the maximum allowed variation in frequency to be fmax Hz.
`-alt alt`	set the altitude at which the mapping is done to be alt km.
`-nav`	do not perform temporal averaging.
`-nlm`	do not exclude data because it exceeds the data limits.
`-nb`	do not exclude data based on the operating parameters.
`-ns`	exclude data with scan flags less than zero.
`-xtd`	create extended output that includes both the power and spectral width measurements and their errors.
`-isort`	calculate the median power and spectral width independently of the velocity distribution.
`-ion`	exclude data marked as ground scatter and only include data marked as ionospheric scatter.
`-gs`	exclude data marked as ionospheric scatter and only include data marked as ground scatter.
`-both`	do not exclude data based on the type flag.
`-inertial`	calculate the grid file in the inertial reference frame.
`-chisham`	calculate the grid file using the Chisham virtual height model.
`-old_aacgm`	calculate the grid file using old AACGM coefficients rather than v2.
`-ecdip`	calculate the grid file using eccentric dipole rather than AACGM.
`fitacfname`	filename of the `fitacf` format file.
`inxname`	filename of the index file.
`-old`	the input file is in the `fit` format, and the output should be in `grd` format. (If the input format is in `cfit` format as specified by the -cfit option, then the output will be in `grd` format).
`fitname`	filename of the `fit` format file.
`-cfit`	the input file is in the `cfit` format.
`cfitfname`	filename of the `cfit` format file.
`fitnames`	filenames of the `fit` format files.
`fitacfnames`	filenames of the `fitacf` format files.
`cfitnames`	filenames of the `cfit` format files.

Description

Creates a grid format file for a single radar site from either a fit, fitacf or cfit format file.

A grid file is a highly processed data product consisting of geo-magnetically located line of sight velocity vectors.

The algorithm optionally applies a median filter to the scan data to remove noise. Each range-beam cell together with its immediate neighbors in the current, preceding and following scans is examined. A weighted sum of all the cells containing scatter is calculated and if this sum exceeds a certain threshold, the median data value of the cells is substituted for the central cell. Various command line options control how the filter is applied.

Once the data has been filtered, the geo-magnetic location of each line of sight velocity measurement is calculated. The vectors are then fixed to an equi-area grid to ensure that the data is not biased according to its location in the radar field of view.

The vectors in each cell are averaged together over a fixed period of time to generate a data record, which is then written to standard output.

The program accepts multiple fit files as input. If more than one input file is provided, the program will concatenate them together for processing. Note that only fit files from a single radar site may be concatenated; the "combine_grid" routine is still necessary for combining data from different radar sites into a single grid file.

In addition to the regular grid file output, the program can also produce "extended" grid files that contain information about the spectral width, power and composition of each data point by specifying the "-xtd" command line option.

Examples

make_grid -vb -old 19991120.kap.fit > 19991120.kap.grd

Generate a grid file from the fit file "19991120.kap.fit" and store it in the file "19991120.kap.grd". Report the status on standard error.

make_grid -i 240 -old 20000510.*.kod.fit > 20000510.kod.grd

Concatenate all the fit files in the current directory to create a grid file with a 4-minute record length. Store the output in the file "20000510.kod.grd".

make_grid -tl 120 -vemax 500 -both -xtd -old 19981012.gbr.fit > 19981012.gbr.grd

Generate a grid file from the fit file "19981012.gbr.fit" using a fixed scan length of 120 seconds. Ignore data points with a velocity error exceeding 500 m/s and process both ionospheric and ground scatter vectors. Store an extended format grid file in "19981012.gbr.grd"

make_grid -nb -nlm -old 19970810.kap.fit > 19970810.kap.grd

Generate a grid file from the fit file "19970810.kap.fit" without applying any thresholds to the vectors and any changes in radar parameters between scans, are ignored. Store the grid file in "19970810.kap.grd"