Observation record.Satnogs-VHF.2021-04-18T01-55-00

Ground-station Satnogs-VHF
Owner N5CNB

Waterfall
DopplerComparaison
PostProcessing

Résumé de l'événement

satellite METEOR-M_2
date 2021-04-18
time 01:55:00
duration 620
freq 1.371e+08
culm 54.4195

Waterfall

The graph at the bottom left gives the waterfall (time on the abscissa, frequency on the ordinate). The graph at the top gives the integrated signal strength in frequency as a function of time. At the bottom right, the average of the spectra over all the measurement times (frequency on the ordinate).

The time range of the measurement is given in the top right part (minimum_time, maximum_time). The frequency range determined by the number of points used by the Fourier transform is given by fmin and fmax. The units used for power (or the energy received in each time slot) could not be determined.

transitfile record.Satnogs-VHF.2021-04-18T01-55-00.transit

Additional capture data

The beginning of the transit is marked by a circle and the end of the transit by a disc.

• paramètres prévus
  filename record.Satnogs-VHF.2021-04-18T01-55-00
  satellite METEOR-M_2
  date 2021-04-18
  time 01:55:00
  samp 250000
  duration 620
  freq 1.371e+08
  culm 54.4195
• paramètres réalisés
  recfile record.Satnogs-VHF.2021-04-18T01-55-00.dat
  start 2021-04-18T01:55:00
  end 2021-04-18T02:05:22
  freq 1.371e+08
  gain 50
  ns 620
  samp 250000
  nsamp 155000000

Gaussian fit

When the intensity of the signal as a function of time follows an approximately Gaussian law, this tool must capture approximately the parameters by non-linear adjustment. The adjustment is carried out using the NLOPT2 library. The behavior is undefined if the law is arbitrary.

abscisses: giga-samples name ordinates: sum_20000(I²+Q²)/1e6

• Resultats du fit
  t0 500000 [ 2 s]
  a 1000
  sigma 1500000
  y0 2000

calpower-stats

• Autres statistiques (de la valeur I²+Q²)
  moyenne 127.596
  max 600.889
  moyenne.debut.fin 58.6181
  hauteur.signal 542.271 [ 27.3422 dB ] (max - moyenne.debut.fin)
  longueur.totale 620
  integrale.signal 42766.3 (somme - moyenne.debut.fin*longueur.totale)

Calculated and measured Doppler comparison

Abscissa: frequency in Hz
Ordinates: time in seconds

sumY2 3.89197e+13
sumDy2 3.92585e+13
dfmin 348.566 sumDy2 3.9116e+13
dtmin -0.505762 sumDy2 3.91158e+13

* Kepler element data for METEOR-M_2

name ‘METEOR-M_2’
satellite_number 40069
central_object EARTH
ephemeris_type UnknownEphemerisType
epoch_year 21
epoch_day 107.23279661

• Kepler elements
  epoch_julday 2459321.73279661
  Time jd 2459321.73280 < 2021-04-17 05:35:13.0627 UTC >
  inclination 98.4677 deg [98 28'04"]
  right_ascension_of_ascending_node 138.709 deg [9:14:50]
  major_radius 7202 km
  eccentricity 0.0006837
  periast_argument 115.149 deg [115 08'56"]
  mean_anomaly 245.0399 deg [245 02'24"]

• Supplemental data
  cc 1.99863353425
  ra 7.20692e+06 [835912]
  rp 7.19707e+06 [826064]
  va 7445.83
  vp 7435.66
  axb 7206.92 x 7206.92
  mammmdt 87.1243
  bstar 0.5864
  mean_motion_1st_deriv -7e-08
  mean_motion_2nd_deriv 0
  mean_motion 14.2068 rev/day 0.0703887 day/rev
  periapsis_distance 7197.07 km
  apoapsis_distance 7206.92 km
  periapsis_mean_height 826.064 km
  apoapsis_mean_height 835.912 km
  rev_number_at_epoch 35134
  tle_age 0.478558 day

* TLE

METEOR-M 2
1 40069U 14037A 21107.23279661 -.00000007 00000-0 15864-4 0 9997
2 40069 98.4677 138.7087 0006837 115.1490 245.0399 14.20683506351344

Spectrum analysis

median 14.7
noise_level_db 14.3986
min 5.06294
max 50.3545
freq_center 6731.9
trig_level_db 10
nbin_rescaling 29.9957
freq_center_trig 6370.28
signal_range_dB 35.9559
theo_range_dB 48.1648 [ 8 bits ]

Post-processing

Credits

Carte meteo METEOR_DEMOD https://github.com/dbdexter-dev/meteor_demod
Carte meteo METEOR_DECODER https://github.com/artlav/meteor_decoder

N5FXH’s page

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