Observation record.Satnogs-VHF.2021-04-18T13-51-00

Ground-station Satnogs-VHF
Owner N5CNB

Waterfall
DopplerComparaison
PostProcessing

Résumé de l'événement

satellite NOAA_19
date 2021-04-18
time 13:51:00
duration 630
freq 1.371e+08
culm 50.1301

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.2021-04-18T13-51-00.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.2021-04-18T13-51-00
  satellite NOAA_19
  date 2021-04-18
  time 13:51:00
  samp 250000
  duration 630
  freq 1.371e+08
  culm 50.1301
• paramètres réalisés
  recfile record.Satnogs-VHF.2021-04-18T13-51-00.dat
  start 2021-04-18T13:51:00
  end 2021-04-18T14:01:32
  freq 1.371e+08
  gain 50
  ns 630
  samp 250000
  nsamp 157500000

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 117.828
  max 497.302
  moyenne.debut.fin 60.4478
  hauteur.signal 436.855 [ 26.4034 dB ] (max - moyenne.debut.fin)
  longueur.totale 630
  integrale.signal 36149.8 (somme - moyenne.debut.fin*longueur.totale)

Calculated and measured Doppler comparison

Abscissa: frequency in Hz
Ordinates: time in seconds

sumY2 4.74331e+14
sumDy2 4.60769e+14
dfmin 144.508 sumDy2 4.60401e+14
dtmin 1.9309 sumDy2 4.60381e+14

* Kepler element data for NOAA 19

name ‘NOAA_19’
satellite_number 33591
central_object EARTH
ephemeris_type UnknownEphemerisType
epoch_year 21
epoch_day 107.13507551

• Kepler elements
  epoch_julday 2459321.63507551
  Time jd 2459321.63508 < 2021-04-17 03:14:30.0524 UTC >
  inclination 99.1886 deg [99 11'19"]
  right_ascension_of_ascending_node 126.307 deg [8:25:14]
  major_radius 7229.92 km
  eccentricity 0.0013072
  periast_argument 306.847 deg [306 50'50"]
  mean_anomaly 53.1499 deg [53 09'00"]

• Supplemental data
  cc 1.99738901308
  ra 7.23937e+06 [868363]
  rp 7.22047e+06 [849461]
  va 7436.07
  vp 7416.66
  axb 7239.37 x 7239.36
  mammmdt 326.404
  bstar 0.6008
  mean_motion_1st_deriv 3.8e-07
  mean_motion_2nd_deriv 0
  mean_motion 14.1246 rev/day 0.0707984 day/rev
  periapsis_distance 7220.47 km
  apoapsis_distance 7239.37 km
  periapsis_mean_height 849.461 km
  apoapsis_mean_height 868.363 km
  rev_number_at_epoch 62826
  tle_age 0.576348 day

* TLE

NOAA 19
1 33591U 09005A 21107.13507551 .00000038 00000-0 46008-4 0 9996
2 33591 99.1886 126.3072 0013072 306.8473 53.1499 14.12460815628266

Spectrum analysis

median 13.5354
noise_level_db 13.5569
min 4.53854
max 52.4736
freq_center 9572.53
trig_level_db 10
nbin_rescaling 29.9957
freq_center_trig 5212.96
signal_range_dB 38.9168
theo_range_dB 48.1648 [ 8 bits ]

Post-processing

Credits

Carte meteo WXTOIMG RESTORED v.2.10.11 https://wxtoimgrestored.xyz/

N5FXH’s page

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