Mapping Model

Modeling the shape of the CCD image

It’s important to understand where each pixel in the CCD originates from in the far field

import matplotlib.pyplot as plt
import numpy as np

import mirage as mr

station = mr.Station()
x, y = np.meshgrid(
    np.arange(station.telescope.ccd.sensor_pixels[0]),
    np.arange(station.telescope.ccd.sensor_pixels[1]),
)
mr.tic('Mapping')
xd, yx = station.telescope.pixel_distortion(
    x,
    y,
    station.telescope.ccd.sensor_pixels[0] // 2,
    station.telescope.ccd.sensor_pixels[1] // 2,
)
mr.toc()

dist = np.sqrt((x - xd) ** 2 + (y - yx) ** 2)

plt.figure()
plt.imshow(dist, cmap='cool')
plt.colorbar(label='Apparent Distance from Pinhole Model [pix]')
cp = plt.contour(dist, levels=[0.01, 0.1, 1, 2, 4, 7], colors='k')
plt.clabel(cp, inline=True, fontsize=14)
plt.title('POGS Pixel Distortion')
plt.tight_layout()

Mapping: 1.48e+00 seconds

Corner of the image principal lines

look_dir = np.array([[1.0, 0.0, 0.0]])
up_dir = np.array([[0.0, 0.0, 1.0]])

plt.figure()
for v in np.arange(0, 101, 10):
    px = np.arange(0, 101, 10)
    py = np.full_like(px, v)

    for x, y in zip([px, py], [py, px]):
        uvs = station.telescope.pixels_to_j2000_unit_vectors(
            look_dir, up_dir, np.vstack((x, y)).T
        )
        pxd, pyd = station.telescope.j2000_unit_vectors_to_pixels(
            look_dir, up_dir, uvs, add_distortion=True
        )
        kwargs = {}
        if v != 0 and v != 100:
            kwargs['alpha'] = 0.15
            plt.scatter(pxd, pyd, c='m', marker='+', **kwargs)
            plt.scatter(x, y, c='k', marker='+', **kwargs)
        plt.plot(x, y, c='k', **kwargs)
        plt.plot(pxd, pyd, c='m', **kwargs)

plt.gca().invert_yaxis()
plt.xlabel('x [pixels]')
plt.ylabel('y [pixels]')
plt.legend(
    ['Distorted', 'Undistorted'],
    loc='upper center',
    bbox_to_anchor=(0.5, 1.10),
    ncol=2,
    fancybox=True,
    shadow=True,
)
plt.xlabel('$x$ pixels')
plt.ylabel('$y$ pixels')
plt.show()