File:Illumination of twilight abu simbel sunrise 1 r 1.svg
Original file (SVG file, nominally 1,053 × 670 pixels, file size: 41 KB)
Captions
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Summary[edit]
| Description |
English: Illumination of twilight, sunrise at Abu simbel , Egypt. Quite a lot of light pollution. |
| Date | |
| Source | Own work |
| Author | Merikanto |
article url
https://www.tandfonline.com/doi/full/10.1080/20909977.2020.1714176
dat on net
https://www.tandfonline.com/doi/full/10.1080/20909977.2020.1714176
Citation of article
TY - JOUR
T1 - Sky twilight brightness at zenith expressed in magnitudes
AU - Nawar, S.
AU - Morcos, A.B.
AU - El Agmy, R.M.
AU - Gad, G.M.A.
AU - Elgohary, Samar
Y1 - 2020/01/01
PY - 2020
DA - 2020/01/01
N1 - doi: 10.1080/20909977.2020.1714176
DO - 10.1080/20909977.2020.1714176
T2 - NRIAG Journal of Astronomy and Geophysics
JF - NRIAG Journal of Astronomy and Geophysics
JO - NRIAG Journal of Astronomy and Geophysics
SP - 63
EP - 70
VL - 9
IS - 1
PB - Taylor & Francis
SN - null
M3 - doi: 10.1080/20909977.2020.1714176
UR - https://doi.org/10.1080/20909977.2020.1714176
ER -
0
Python 3 source code
import math
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
- abu simbel, morning s
df = pd.read_csv('t0004-10.1080_20909977.2020.1714176.csv', skiprows=3)
print (df)
- sun sepression angle
depression=np.array(df.iloc[:, 0])
- sky brightness v, b , r band
log_b=np.array(df.iloc[:, 1])
log_v=np.array(df.iloc[:, 3])
log_r=np.array(df.iloc[:, 5])
- realtve sky brithness by band, relative to sunrise or depression 0
rlog_v=(log_v-log_v[0])
rlog_b=(log_b-log_b[0])
rlog_r=(log_r-log_r[0])
altitude=depression*-1
print (depression)
print(log_v)
log10_lux=math.log10((585+300)/2 )+rlog_v
- deps2=np.linspace(0,30)
x=altitude
y=log10_lux
x2 = np.linspace(-21, 0, 210)
- fit1=np.polyfit(x, y, 4)
fit1=[-1.47753433e-04 ,-6.73705380e-03, -8.69477852e-02 , 5.71647350e-02,2.62997932e+00]
print(fit1)
- print (fit1[2], math.pow(10, fit1[2]))
yn = np.poly1d(fit1)
y2=yn(x2)
alt2=-18
lux2=math.pow(10,yn(alt2))
print(alt2,lux2)
fig = plt.figure()
ax = fig.gca()
ax.set_xticks(np.arange(-21, 3, 3))
ax.set_yticks(np.arange(-4, 3,1))
plt.xlabel("Altitude of Sun, degrees", size=18)
plt.ylabel("Log10 of illumination lx", size=18)
plt.yticks(fontsize=18)
plt.xticks(fontsize=18)
plt.suptitle("Illumination of twilight, luxes", fontsize=22)
plt.title("Abu Simbel, Egypt - sunrise ", fontsize=18)
- plt.plot(alts1, logillums1, linewidth=6, color="#ff7f00")
plt.plot(x2,y2,linewidth=6, color="#ff7f00" )
plt.plot(altitude, log10_lux, linestyle=":", linewidth=4, color="#ffff00")
plt.grid()
plt.axvline(x = 0, color = '#FFFF00', label = 'Sunset')
plt.axvline(x = -6, color = '#7f7f00', label = 'Civil twilight ends')
plt.axvline(x = -12, color = '#3f3f00', label = 'Nautical twilight ends')
plt.axvline(x = -18, color = '#1f1f00', label = 'Astronomical twilight ends')
plt.text(-5, 0, "Civil twilight", size=17)
plt.text(-11.5, -1, "Nautical twilight", size=17)
plt.text(-17.5, -2, "Astronomical twi.", size=17)
plt.show()
Licensing[edit]
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 13:09, 16 August 2023 | | 1,053 × 670 (41 KB) | Merikanto (talk | contribs) | Uploaded own work with UploadWizard |
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