Re-projecting from CAR to CEA

The pfsspy solver takes a cylindrical-equal-area (CEA) projected magnetic field map as input, which is equally spaced in sin(latitude). Some synoptic field maps are equally spaced in latitude however, which is a plate carée (CAR) projection.

This example shows how to use the pfsspy.utils.car_to_cea function to reproject a CAR projection to a CEA projection that pfsspy can take as input.

import matplotlib.pyplot as plt

from pfsspy import sample_data, utils

Load a sample ADAPT map, which has a CAR projection

adapt_maps = utils.load_adapt(sample_data.get_adapt_map())
adapt_map_car = adapt_maps[0]

Out:

Files Downloaded:   0%|          | 0/1 [00:00<?, ?file/s]

pfsspy.adapt40311_03k012_202001010000_i00005600n1.fts.gz:   0%|          | 0.00/3.11M [00:00<?, ?B/s]

pfsspy.adapt40311_03k012_202001010000_i00005600n1.fts.gz:   0%|          | 100/3.11M [00:00<1:31:19, 567B/s]

pfsspy.adapt40311_03k012_202001010000_i00005600n1.fts.gz:  10%|9         | 301k/3.11M [00:00<00:02, 1.35MB/s]

pfsspy.adapt40311_03k012_202001010000_i00005600n1.fts.gz:  32%|###2      | 1.00M/3.11M [00:00<00:00, 3.53MB/s]

pfsspy.adapt40311_03k012_202001010000_i00005600n1.fts.gz:  76%|#######5  | 2.35M/3.11M [00:00<00:00, 7.07MB/s]


Files Downloaded: 100%|##########| 1/1 [00:00<00:00,  1.40file/s]
Files Downloaded: 100%|##########| 1/1 [00:00<00:00,  1.40file/s]

Re-project into a CEA projection

adapt_map_cea = utils.car_to_cea(adapt_map_car)

Out:

INFO: Missing metadata for solar radius: assuming the standard radius of the photosphere. [sunpy.map.mapbase]
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/stable/lib/python3.7/site-packages/sunpy/map/mapbase.py:608: SunpyMetadataWarning: Missing metadata for observer: assuming Earth-based observer.

  obs_coord = self.observer_coordinate

Plot the original map and the reprojected map

plt.figure()
adapt_map_car.plot()
plt.figure()
adapt_map_cea.plot()

plt.show()
  • 2020-01-01 00:00:00
  • 2020-01-01 00:00:00

Total running time of the script: ( 0 minutes 2.004 seconds)

Gallery generated by Sphinx-Gallery