diff options
Diffstat (limited to 'astro')
| -rwxr-xr-x | astro/oskar/fits2skymodel.py | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/astro/oskar/fits2skymodel.py b/astro/oskar/fits2skymodel.py index eefeb1c..c07c9de 100755 --- a/astro/oskar/fits2skymodel.py +++ b/astro/oskar/fits2skymodel.py @@ -50,8 +50,9 @@ class SkyModel: Input image array; unit [K] (brightness temperature) freq : float Frequency of the input image slice; unit [MHz] - pixsize : float - Pixel size of the input image; unit [arcmin] + pixelsize : float + Pixel size of the input image; + Unit: [arcsec] ra0, dec0 : float The coordinate of the image center; unit [deg] minvalue : float, optional @@ -64,13 +65,13 @@ class SkyModel: The WCS projection for the image; default "TAN" TODO: support "SIN" etc. """ - def __init__(self, image, freq, pixsize, ra0, dec0, + def __init__(self, image, freq, pixelsize, ra0, dec0, minvalue=1e-4, mask=None, projection="TAN"): - self.image = image # K (brightness temperature) - self.freq = freq # MHz - self.pixsize = pixsize # arcmin - self.ra0 = ra0 # deg - self.dec0 = dec0 # deg + self.image = image # [K] (brightness temperature) + self.freq = freq # [MHz] + self.pixelsize = pixelsize # [arcsec] + self.ra0 = ra0 # [deg] + self.dec0 = dec0 # [deg] self.minvalue = minvalue self.mask = mask self.projection = projection @@ -82,7 +83,7 @@ class SkyModel: WCS for the given image slice. """ shape = self.image.shape - delta = self.pixsize / 60.0 # deg + delta = self.pixelsize / 3600.0 # [arcsec] -> [deg] wcs_ = WCS(naxis=2) wcs_.wcs.ctype = ["RA---"+self.projection, "DEC--"+self.projection] wcs_.wcs.crval = np.array([self.ra0, self.dec0]) @@ -97,7 +98,7 @@ class SkyModel: header["FREQ"] = (self.freq, "Frequency [MHz]") header["RA0"] = (self.ra0, "Center R.A. [deg]") header["DEC0"] = (self.dec0, "Center Dec. [deg]") - header["PIXSIZE"] = (self.pixsize, "Pixel size [arcmin]") + header["PixSize"] = (self.pixelsize, "Pixel size [arcsec]") return header @property @@ -107,7 +108,7 @@ class SkyModel: http://www.iram.fr/IRAMFR/IS/IS2002/html_1/node187.html """ - pixarea = np.deg2rad(self.pixsize/60.0) ** 2 # [sr] + 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] @@ -164,7 +165,7 @@ class SkyModel: nsources = sky.shape[0] logger.info("Number of sources: %d" % nsources) header = ("Frequency = %.3f [MHz]\n" % self.freq + - "Pixel size = %.2f [arcmin]\n" % self.pixsize + + "Pixel size = %.2f [arcsec]\n" % self.pixelsize + "RA0 = %.4f [deg]\n" % self.ra0 + "Dec0 = %.4f [deg]\n" % self.dec0 + "Number of sources = %d\n\n" % len(sky) + @@ -219,9 +220,9 @@ def main(): parser.add_argument("-d", "--dec0", dest="dec0", type=float, default=-27.0, help="Dec. of the image center") - parser.add_argument("-p", "--pix-size", dest="pixsize", type=float, - help="image pixel size [arcmin]; " + - "(default: obtain from the FITS header 'PIXSIZE')") + parser.add_argument("-p", "--pixel-size", dest="pixelsize", type=float, + help="image pixel size [arcsec]; " + + "(default: obtain from the FITS header 'PixSize')") parser.add_argument("-f", "--freq", dest="freq", type=float, help="frequency [MHz] the image measured; " + "(default: obtain from the FITS header 'FREQ')") @@ -263,9 +264,12 @@ def main(): header = f[0].header logger.info("Read image slice: %s" % args.infile) freq = args.freq if args.freq else header["FREQ"] # [MHz] - pixsize = args.pixsize if args.pixsize else header["PIXSIZE"] # [arcmin] + if args.pixelsize: + pixelsize = args.pixelsize # [arcsec] + else: + pixelsize = header["PixSize"] # [arcsec] logger.info("Frequency: %.2f [MHz]" % freq) - logger.info("Pixel size: %.2f [arcmin]" % pixsize) + logger.info("Pixel size: %.2f [arcsec]" % pixelsize) minvalue = 1e-4 # i.e., 0.1 [mK] mask = None if args.minvalue: @@ -276,7 +280,7 @@ def main(): mask = fits.open(args.mask)[0].data.astype(np.bool) logger.info("Minimum threshold: %g [K]" % minvalue) skymodel = SkyModel(image=image, freq=freq, ra0=args.ra0, dec0=args.dec0, - pixsize=pixsize, minvalue=minvalue, mask=mask) + pixelsize=pixelsize, minvalue=minvalue, mask=mask) logger.info("Conversion [K] -> [Jy/pixel]: %g" % skymodel.factor_K2JyPixel) skymodel.write_sky_model(outfile, clobber=args.clobber) if args.osmfits: |