Observation record.Satnogs-VHF.2021-04-12T20-30-00

Ground-station Satnogs-VHF
Owner N5CNB

Waterfall
DopplerComparaison
PostProcessing

Résumé de l'événement

satellite LUSAT_(LO-19)
date 2021-04-12
time 20:30:00
duration 600
freq 4.37125e+08
culm 82.279

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.2021-04-12T20-30-00.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.2021-04-12T20-30-00
  satellite LUSAT_(LO-19)
  date 2021-04-12
  time 20:30:00
  samp 250000
  duration 600
  freq 4.37125e+08
  culm 82.279
• paramètres réalisés
  recfile record.Satnogs-VHF.2021-04-12T20-30-00.dat
  start 2021-04-12T20:30:00
  end 2021-04-12T20:40:02
  freq 4.37125e+08
  gain 50
  ns 600
  samp 250000
  nsamp 150000000

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 2.31984
  max 2.6589
  moyenne.debut.fin 2.3398
  hauteur.signal 0.319104 [ -4.96068 dB ] (max - moyenne.debut.fin)
  longueur.totale 600
  integrale.signal -11.975 (somme - moyenne.debut.fin*longueur.totale)

Calculated and measured Doppler comparison

Abscissa: frequency in Hz
Ordinates: time in seconds

sumY2 1.46827e+11
sumDy2 4.40048e+09
dfmin 578.552 sumDy2 4.91144e+07
dtmin 0.0149227 sumDy2 4.90926e+07

* Kepler element data for LUSAT_(LO-19)

name ‘LUSAT_(LO-19)’
satellite_number 20442
central_object EARTH
ephemeris_type UnknownEphemerisType
epoch_year 21
epoch_day 101.87491174

• Kepler elements
  epoch_julday 2459316.37491174
  Time jd 2459316.37491 < 2021-04-11 20:59:52.0374 UTC >
  inclination 98.7348 deg [98 44'05"]
  right_ascension_of_ascending_node 56.7599 deg [3:47:02]
  major_radius 7160.73 km
  eccentricity 0.0011823
  periast_argument 2.6248 deg [2 37'29"]
  mean_anomaly 357.4995 deg [357 29'58"]

• Supplemental data
  cc 1.99763819237
  ra 7.1692e+06 [798187]
  rp 7.15226e+06 [781255]
  va 7470.98
  vp 7453.34
  axb 7169.2 x 7169.19
  mammmdt 51.7872
  bstar 0.3317
  mean_motion_1st_deriv -9e-08
  mean_motion_2nd_deriv 0
  mean_motion 14.3298 rev/day 0.0697845 day/rev
  periapsis_distance 7152.26 km
  apoapsis_distance 7169.2 km
  periapsis_mean_height 781.255 km
  apoapsis_mean_height 798.187 km
  rev_number_at_epoch 63129
  tle_age 0.759602 day

* TLE

LUSAT (LO-19)
1 20442U 90005G 21101.87491174 -.00000009 00000-0 13317-4 0 9991
2 20442 98.7348 56.7599 0011823 2.6248 357.4995 14.32982052631290

Spectrum analysis

median 1.78123
noise_level_db 1.84353
min -5.91505
max 29.4203
freq_center -1622.51
trig_level_db 10
nbin_rescaling 29.9957
freq_center_trig -1013.91
signal_range_dB 27.5768
theo_range_dB 48.1648 [ 8 bits ]

Post-processing

number of decodings: 0

Credits

Decodage gr-satellites v3.6.0 (Daniel Estevez)

N5FXH’s page

Up