Pixels below the horizon being passed into UVBeam

[nicholebarry]

Some pixels below the horizon are being passed to UVBeam. I've traced this back to line 184 in init_beam (ra_arr, dec_arr = pixel_to_radec(xvals_celestial, yvals_celestial, obs["astr"])). Some dec values that are created from this are a bit below the horizon, and thus should have been filled by nans instead of a value.

pixel_to_radec uses WCS to do the conversion. So perhaps something about the metadata is incorrect?

Here is the original error stack:

  File "/fred/oz048/nbarry/PyFHD/PyFHD/pyfhd.py", line 301, in main
    psf = create_psf(obs, pyfhd_config, logger)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/PyFHD/PyFHD/beam_setup/beam.py", line 54, in create_psf
    antenna, psf, beam = init_beam(obs, pyfhd_config, logger)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/PyFHD/PyFHD/beam_setup/antenna.py", line 240, in init_beam
    antenna["iresponse"], antenna["projection"] = general_jones_matrix(
                                                  ^^^^^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/PyFHD/PyFHD/beam_setup/antenna.py", line 391, in general_jones_matrix
    f_vals = f_beam.compute_response(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/software/pyuvdata/fhd_beam_decompose/lib/python3.11/site-packages/pyuvdata/beam_interface.py", line 306, in compute_response
    interp_data, _ = self.beam.interp(
                     ^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/software/pyuvdata/fhd_beam_decompose/lib/python3.11/site-packages/pyuvdata/uvbeam/uvbeam.py", line 2636, in interp
    interp_arrays = getattr(self, interp_func)(
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/fred/oz048/nbarry/software/pyuvdata/fhd_beam_decompose/lib/python3.11/site-packages/pyuvdata/uvbeam/uvbeam.py", line 2029, in _interp_az_za_rect_spline
    self._check_interpolation_domain(az_array, za_array, phi_use, theta_use)
  File "/fred/oz048/nbarry/software/pyuvdata/fhd_beam_decompose/lib/python3.11/site-packages/pyuvdata/uvbeam/uvbeam.py", line 1824, in _check_interpolation_domain
    raise ValueError(
ValueError: at least one interpolation location is outside of the UVBeam pixel coverage. The zenith angles values are outside UVBeam coverage.```