Noise Sampling

Plots the accumulation of noise in the CCD due to integration noise, readout noise, and truncation noise.

import matplotlib.animation as animation
import matplotlib.pyplot as plt
import numpy as np

Integration noise

d = 10
t = np.linspace(0, 1, 100)
grid = np.zeros((d, d))

fig, ax = plt.subplots(figsize=(5, 5))

actor = ax.imshow(grid, cmap='gray', vmin=0, vmax=255)
plt.xticks([])
plt.yticks([])


def animate(i):
    global grid
    grid += np.random.poisson(1, (d, d))
    actor.set_data(grid)
    plt.tight_layout()
    actor.vmin = 0
    plt.title(f'Integrating... {i / t.size * 100:.1f}%')
    return (actor,)


ani = animation.FuncAnimation(fig, animate, repeat=True, frames=t.size, interval=50)
plt.show()

Once Loop Reflect

Readout noise

t = np.linspace(0, 1, 10)
grid = np.zeros((d, d))

fig, ax = plt.subplots(figsize=(5, 5))

actor = ax.imshow(grid, cmap='gray', vmin=-2, vmax=2)
plt.xticks([])
plt.yticks([])


def animate(i):
    global grid
    grid = np.random.normal(0, 1, (d, d))
    actor.set_data(grid)
    plt.tight_layout()
    plt.title(f'Readout Sample {i+1}/{t.size}')
    return (actor,)


ani = animation.FuncAnimation(fig, animate, repeat=True, frames=t.size, interval=500)
plt.show()

Once Loop Reflect

Truncation noise

t = np.linspace(0, 1, 10)
grid = np.zeros((d, d))

fig, ax = plt.subplots(figsize=(5, 5))

actor = ax.imshow(grid, cmap='gray', vmin=-0.5, vmax=0.5)
plt.xticks([])
plt.yticks([])


def animate(i):
    global grid
    grid = 0.5 - np.random.random((d, d))
    actor.set_data(grid)
    plt.tight_layout()
    plt.title(f'Truncation Sample {i+1}/{t.size}')
    return (actor,)


ani = animation.FuncAnimation(fig, animate, repeat=True, frames=t.size, interval=500)
plt.show()

Once Loop Reflect