Background Signals at Zenith

Plotting the general behavior of background signals for zodiac light, moonlight, and integrated starlight at zenith

import numpy as np
import pyvista as pv

import mirage as mr
import mirage.vis as mrv

Let’s choose a point after sunset on the US east coast

date = mr.utc(2023, 3, 1, 1)
integration_time_s = 1.0  # seconds

We can then generate the background signals for a set of spiral points

npts = int(1e6)
pts = 1e4 * mr.spiral_sample_sphere(npts)
sv = np.tile(mr.hat(mr.sun(date)), (npts, 1))
station = mr.Station(preset='pogs')
tdargs = (
    station,
    pts,
    pts / 2 + 0.01,
    integration_time_s,
)
ss = mr.integrated_starlight_signal(*tdargs)


def plot_sig(pl, s, cmap, scale=1):
    mrv.scatter3(
        pl,
        scale * pts,
        scalars=s,
        cmap=cmap,
        opacity=(s - np.min(s)) / (np.max(s) - np.min(s)),
        point_size=15,
        show_scalar_bar=False,
        lighting=False,
    )


pl = pv.Plotter()
(mrv.plot_earth(pl, mode='eci', date=date),)
plot_sig(pl, ss, 'fire', scale=1.2)
pl.camera.position = (35e3, 35e3, -8e3)

mrv.orbit_plotter(pl)

A still frame

pl = pv.Plotter()
(mrv.plot_earth(pl, mode='eci', date=date),)
plot_sig(pl, ss, 'fire', scale=1.2)
pl.camera.position = (35e3, 35e3, -8e3)
pl.show()