From 97a5e67495c3a92e8bb82275f9168843bb7cb1ac Mon Sep 17 00:00:00 2001 From: Aaron LI Date: Sun, 3 Sep 2017 17:03:37 +0800 Subject: fits2skymodel.py: Use astropy.units to simplify unit conversion --- astro/oskar/fits2skymodel.py | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'astro') diff --git a/astro/oskar/fits2skymodel.py b/astro/oskar/fits2skymodel.py index a336515..e5b2ea3 100755 --- a/astro/oskar/fits2skymodel.py +++ b/astro/oskar/fits2skymodel.py @@ -32,7 +32,7 @@ from datetime import datetime import numpy as np import astropy.io.fits as fits -import astropy.constants as ac +import astropy.units as au from astropy.wcs import WCS @@ -106,14 +106,11 @@ class SkyModel: def factor_K2JyPixel(self): """ Conversion factor to convert brightness unit from 'K' to 'Jy/pixel' - - http://www.iram.fr/IRAMFR/IS/IS2002/html_1/node187.html """ - pixarea = np.deg2rad(self.pixelsize/3600.0) ** 2 # [sr] - kB = ac.k_B.si.value # Boltzmann constant [J/K] - c0 = ac.c.si.value # speed of light in vacuum [m/s] - freqHz = self.freq * 1e6 # [Hz] - factor = 2*kB * 1.0e26 * pixarea * (freqHz/c0)**2 + pixarea = (self.pixelsize * au.arcsec) ** 2 + freq = self.freq * au.MHz + equiv = au.brightness_temperature(pixarea, freq) + factor = au.K.to(au.Jy, equivalencies=equiv) return factor @property -- cgit v1.2.2