MetFns (version 1.0)

filter.h: Selection of visual meteor data by radiant elevation

Description

Selects data for a given visual meteor dataset, specified shower and its radiant elevation or interval of radiant elevations.

Usage

filter.h(data, shw, Ralpha = NULL, Delta = NULL, h.low = 10, h.up = 90)

Arguments

data

data frame consisting of visual meteor data (rate or magnitude data).

shw

character string consisting of three capital letters which represent meteor shower code.

Ralpha

numeric vector with value between 0 and 360, specifying right ascension of the radiant, in degrees.

Delta

numeric vector with value between -90 and +90, specifying declination of the radiant, in degrees.

h.low

numeric vector with value between 10 (default) and 90, specifying lower boundary of radiant elevation in degrees.

h.up

numeric vector with value between 10 and 90 (default), specifying upper boundary of radiant elevation in degrees.

Value

• filter.h returns data frame containing observations corresponding to the radiant elevation between h.low and h.up.

Details

Radiant elevation h is measured from the observer's horizon towards zenith and it takes value between 10 and 90 degrees. If right ascension and declination of shower radiant are not specified, the values from the data frame radiant are used.

References

http://www.imo.net/data/visual Rendtel J. and Arlt R., editors (2008). IMO Handbook For Meteor Observers. IMO, Potsdam.

See Also

filter,filter.totcor

Examples

## select visual meteor data for the elevation of Perseids radiant between 30 and 60 degrees,
## period between 1-20th August 2011

## rate data for the year 2011
require(astroFns)
data(rate11)
ratePer<-filter.date(rate11,year=2011,month=8,day.beg=1,day.end=20)
filter.h(ratePer,shw="PER", h.low=30,h.up=60)

## magnitude data for the year 2011 
data(magn11)    
magnPer<-filter.date(magn11,year=2011,month=8,day.beg=1,day.end=20)
filter.h(magnPer,shw="PER",h.low=30,h.up=60)