orbit {skyscapeR}

Calculate visible path of celestial object at given location

Description

This function calculates the visible path of a celestial object from any location on earth. It outputs a skyscapeR.orbit object, which includes AZ and ALT information.

Usage

orbit(dec, loc, res = 0.25, refraction, atm, temp)

Arguments

dec

Declination of object.

loc

Location, either a skyscapeR.object or a vector containing the latitude and longitude of location, in this order.

res

The resolution (in degrees of RA) with which to calculate the path.

refraction

(Optional) Whether atmospheric refraction is to be taken into account. If not given the value set by skyscapeR.vars will be used instead.

atm

(Optional) Atmospheric pressure for refraction calculation. If not given the value set by skyscapeR.vars will be used instead.

temp

(Optional) Atmospheric temperature for refraction calculation. If not given the value set by skyscapeR.vars will be used instead.

Examples

# Visible path of sun on june solstice on year 3999 BC from London:
sun.dec <- jS(-4000)
london.lat <- 51.5074 #N
london.lon <- -0.1278 #W
loc <- c( london.lat, london.lon, 0 )
path <- orbit(sun.dec, loc)
plot(path$az, path$alt, ylim=c(0,90), type='l', xlab='AZ', ylab='ALT', col='red', lwd=2)