第二个例子#
另一种创建WCS对象的方法是使用Python字典。这使我们能够更好地控制 NAXISn
适合头关键字,否则会自动默认为零,如上面所示的第一个示例所示。
# Define the astropy.wcs.WCS object using a Python dictionary as input
import astropy.wcs
wcs_dict = {
"CTYPE1": "WAVE ",
"CUNIT1": "Angstrom",
"CDELT1": 0.2,
"CRPIX1": 0,
"CRVAL1": 10,
"NAXIS1": 5,
"CTYPE2": "HPLT-TAN",
"CUNIT2": "deg",
"CDELT2": 0.5,
"CRPIX2": 2,
"CRVAL2": 0.5,
"NAXIS2": 4,
"CTYPE3": "HPLN-TAN",
"CUNIT3": "deg",
"CDELT3": 0.4,
"CRPIX3": 2,
"CRVAL3": 1,
"NAXIS3": 3,
}
input_wcs = astropy.wcs.WCS(wcs_dict)