co_refract_forward {astrolibR}R Documentation

Calculate the true altitude of a celestial object from an observed altitude.

Description

Calculate the true altitude of a celestial object from an observed altitude. This function is called by co_refract, the function to correct altitude due to atmospheric refraction.

Usage

co_refract_forward(a, p = 1010, t = 283)

Arguments

a

The observed (‘apparent’) altitude, in degrees

p

Atmospheric pressure, in millibars (default=1010)

t

Ground temperature, in degrees Celsius (default=0)

Details

See description for co_refract.

Value

R

Correction to apparent altitude, subtracted from a, in degrees

Note

The IDL documentation may be incorrect: the input variable t appears to be in degrees Kelvin. The value t=0 is converted to 283, but other values should be in Kelvin.

Author(s)

Chris O'Dell 2002

Arnab Chakraborty R version 2013

See Also

co_refract

Examples

co_refract_forward (30) 

[Package astrolibR version 0.1 Index]