"""Telescope coordinate information"""
import numpy as np
import logging
_log = logging.getLogger('pynrc')
__epsilon = np.finfo(float).eps
import pysiaf
from pysiaf import JWST_PRD_VERSION, rotations, Siaf
# Create this once since it takes time to call multiple times
# from ..nrc_utils import siaf_nrc
siaf_nrc = Siaf('NIRCam')
siaf_nrc.generate_toc()
# Functions transferred to webbpsf_ext
from webbpsf_ext.coords import dist_image
from webbpsf_ext.coords import xy_to_rtheta, rtheta_to_xy, xy_rot
from webbpsf_ext.coords import ap_radec, radec_to_coord, radec_to_v2v3, v2v3_to_pixel
from webbpsf_ext.coords import get_NRC_v2v3_limits, NIRCam_V2V3_limits
from webbpsf_ext.coords import get_NRC_v2v3_limits as get_v2v3_limits # Original name
from webbpsf_ext.coords import plotAxes
# New stuff from webbpsf_ext
from webbpsf_ext.coords import gen_sgd_offsets, get_idl_offset, radec_offset
from webbpsf_ext.coords import jwst_point
from webbpsf_ext.coron_masks import det_to_sci, sci_to_det
[docs]
def oversampled_coords(coords, oversample):
"""Transform image index to oversampled image index
Assumes 0-based indexing where the center of a pixel
corresponds to the integer index. That is, the center
of the first pixel is at 0.0, and the center of the last
pixel is at N-1.0 where N is the number of pixels.
Parameters
----------
coords : float or array-like
Image index or indices
oversample : int
Oversampling factor
Returns
-------
float or array-like
Oversampled image index or indices
"""
return (coords + 0.5) * oversample - 0.5
###########################################################################
#
# NIRCam Coordinate Systems
#
###########################################################################
[docs]
def Tel2Sci_info(channel, coords, pupil=None, output='sci', return_apname=False, **kwargs):
"""Telescope coords converted to Science coords
Returns the detector name and position associated with input coordinates.
This is alway relative to a full frame detector aperture. The detector
that is chosen is the one whose center is closest to the input coords.
Parameters
----------
channel : str
'SW' or 'LW'
coords : tuple
Telescope coordinates (V2,V3) in arcsec.
output : str
Type of desired output coordinates.
* det: pixels, in raw detector read out axes orientation
* sci: pixels, in conventional DMS axes orientation
* idl: arcsecs relative to aperture reference location.
* tel: arcsecs V2,V3
"""
# Figure out the detector and pixel position for some (V2,V3) coord
V2, V3 = coords
if (pupil is not None) and ("LYOT" in pupil):
# There are no full frame SIAF aperture for ModB coron
if 'SW' in channel:
detnames = ['A2', 'A4']
apnames = ['NRCA2_FULL_MASK210R', 'NRCA4_FULL_MASKSWB']
else:
detnames = ['A5']
apnames = ['NRCA5_FULL_MASK335R']
else:
swa = ['A1', 'A2', 'A3', 'A4']
swb = ['B1', 'B2', 'B3', 'B4']
lwa = ['A5']
lwb = ['B5']
detnames = swa + swb if 'SW' in channel else lwa + lwb
apnames = ['NRC'+det+'_FULL' for det in detnames]
# Find center positions for each apname
cens = []
for apname in apnames:
ap = siaf_nrc[apname]
try:
vals = ap.tel_to_sci(V2, V3)
except AttributeError:
vals = ap.Tel2Sci(V2, V3)
cens.append(vals)
cens = np.array(cens)
# Select that with the closest position
dist = np.sqrt((cens[:,0]-1024)**2 + (cens[:,1]-1024)**2)
ind = np.where(dist==dist.min())[0][0]
# Find detector "science" coordinates
detector = 'NRC'+detnames[ind]
apname = apnames[ind]
ap = siaf_nrc[apname]
try:
detector_position = ap.convert(V2, V3, 'tel', output.lower())
except TypeError:
detector_position = ap.convert(V2, V3, frame_from='Tel', frame_to=output)
if return_apname:
return detector, detector_position, apname
else:
return detector, detector_position
[docs]
def siafap_sci_coords(inst, coord_vals=None, coord_frame='tel'):
"""
Return the detector, sci position, and full frame aperture name
for a set of coordinate values.
"""
self = inst
# Get a reference point if coord_vals not set
if coord_vals is None:
try:
ap = self.siaf_ap
except:
_log.warning("`self.siaf_ap` may not be set")
apname = self.get_siaf_apname()
if apname is None:
_log.warning('No suitable aperture name defined to determine ref coords')
return None, None, None
else:
_log.warning('`self.siaf_ap` not defined; assuming {}'.format(apname))
ap = self.siaf[apname]
if coord_frame=='tel':
coord_vals = (ap.V2Ref, ap.V3Ref)
elif coord_frame=='sci':
coord_vals = (ap.XSciRef, ap.YSciRef)
elif coord_frame=='det':
coord_vals = (ap.XDetRef, ap.YDetRef)
elif coord_frame=='idl':
coord_vals = (0.0, 0.0)
# Determine V2/V3 coordinates
detector = detector_position = apname = None
v2 = v3 = None
cframe = coord_frame.lower()
if cframe=='tel':
v2, v3 = coord_vals
elif cframe in ['det', 'sci', 'idl']:
x, y = coord_vals[0], coord_vals[1]
try:
v2, v3 = self.siaf_ap.convert(x,y, cframe, 'tel')
except:
apname = self.get_siaf_apname()
if apname is None:
_log.warning('No suitable aperture name defined to determine V2/V3 coordinates')
else:
_log.warning('`self.siaf_ap` not defined; assuming {}'.format(apname))
ap = self.siaf[apname]
v2, v3 = ap.convert(x,y,cframe, 'tel')
_log.warning('Update `self.siaf_ap` for more specific conversions to V2/V3.')
else:
_log.warning("coord_frame setting '{}' not recognized.".format(coord_frame))
# Update detector, pixel position, and apname to pass to
if v2 is not None:
res = Tel2Sci_info(self.channel, (v2, v3), output='sci', return_apname=True)
detector, detector_position, apname = res
return (detector, detector_position, apname)