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en:data-outputs [2017/01/05 18:39] – [Spectral records description] fluktuaciaen:data-outputs [2019/04/25 15:33] (current) – [Spectral records description] fluktuacia
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 ====== Bolidozor data outputs ====== ====== Bolidozor data outputs ======
  
-The data produced by the detection stations are sent to the [[en:servers|main data server]] running a [[http://space.astro.cz/bolidozor/support/js9browser/#/bolidozor/|JS9browser]] tool. It enables to view the visual portion of the data. Statistical data are available on [[http://rt.bolidozor.cz/|Bolidozor RealTime web]].+Data produced by detection stations are sent to the [[en:servers|main data server]] running a [[http://space.astro.cz/bolidozor/support/js9browser/#/bolidozor/|JS9browser]] tool, which enables to view the visual portion of the data. Statistical data are available on [[http://rt.bolidozor.cz/|Bolidozor RealTime web]].
  
 There are several types of files among the data records: There are several types of files among the data records:
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-JS9 web viewer enables viewing only the first two records. A specialised application is required to see the rest of the records. The description of how the data files are sorted can be found on [[en:convention|directory convenctions]] webpage. All the time records are stored either as [[https://en.wikipedia.org/wiki/Unix_time|Unix time]] or [[https://en.wikipedia.org/wiki/Coordinated_Universal_Time|UTC]].+JS9 web viewer enables viewing only the first two types of records. A specialised application is required to see the rest of the records. The description of how the data files are sorted can be found at [[en:convention|directory convenctions]] webpage. All the time records are stored either as [[https://en.wikipedia.org/wiki/Unix_time|Unix time]] or [[https://en.wikipedia.org/wiki/Coordinated_Universal_Time|UTC]].
  
 ===== Records generation ===== ===== Records generation =====
  
-The records are generated by a software running on the detection stations. Majority of data are produced by [[en:radio-observer|Radio-observer]] software. Other auxiliary meta-data outputs are generated by a software maintaining an integrity of data flow from the stations. +The records are generated by a software running on detection stations. Majority of data are produced by [[en:radio-observer|Radio-observer]] software. Other auxiliary meta-data outputs are generated by a software maintaining an integrity of data flow from the stations. 
  
 ===== Spectral records description ===== ===== Spectral records description =====
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-The radar emitting frequency corresponds to the vertical intersected with the average positions of the meteor trails. This signal is static and thus has almost entirely zero [[https://en.wikipedia.org/wiki/Doppler_effect|Doppler shift]]. +The radar emitting frequency corresponds to the vertical line intersected with the average positions of the meteor trails. This signal is static and thus has almost entirely zero [[https://en.wikipedia.org/wiki/Doppler_effect|Doppler shift]]. 
    
 {{:cs:outputs:js9browser_meteor.png?600|A typical picture of meteor generated by JS9Browser programme.}} {{:cs:outputs:js9browser_meteor.png?600|A typical picture of meteor generated by JS9Browser programme.}}
  
  
-The lower portion of the record shows a head-echo - a signal, always beginning at higher frequencies than the meteor trail. Head-echo is a signal formed by the reflection from an ionised plasma at the front of the meteor during its fly-by. It is a moving object whose signal (due to a considerable speed up to tens of km/s) has a large doppler shift that passes through zero (at the point of the shortest sum of distances transmitter -> meteor -> receiver). Some meteors lack head-echo signal as the geometry of their fly-by does not allow the reflection to the receiver station. On the other side, other meteors have a head-echo extending even behind the point of the zero doppler shift.+The lower portion of the record shows a head-echo - a signal, always beginning at higher frequencies than the meteor trail. Head-echo is a signal formed by the reflection from an ionised plasma at the front of the meteor during its fly-by. It is a moving object whose signal (due to a considerable speed up to tens of km/s) has a large doppler shift that passes through zero (at the point of the shortest sum of distances transmitter -> meteor -> receiver). Some meteors lack head-echo signal as geometry of their fly-by does not allow reflection towards the receiver station. On the other side, other meteors have a head-echo extending even behind the point of the zero doppler shift. 
 + 
 +Following the area of a head-echo signal there is an area of a static reflection from the meteor trail. Its intensity varies in time. The change in intensity is caused by a progressive recombination of a plasma trail of the meteor and periodic changes in intensity are caused by a spatial modulation of the radar signal. 
 + 
 +==== FITS header content ==== 
 + 
 + 
 +  SIMPLE  =                    T / file does conform to FITS standard              
 +  BITPIX  =                  -32 / number of bits per data pixel                   
 +  NAXIS                      2 / number of data axes                             
 +  NAXIS1  =                    2 / length of data axis 1                           
 +  NAXIS2  =               460800 / length of data axis 2                           
 +  EXTEND  =                    T / FITS dataset may contain extensions             
 +  ORIGIN  = 'SVAKOV-R12'                                                           
 +  DATE    = '2017-09-23T05:00:57' / system time of file creation (filled in by FITS library)    
 +  DATE-OBS= '2017-09-23T05:00:47' / time of observing the event derived from sampling 
 +  CTYPE2  = 'TIME    '           / in seconds                                      
 +  CRPIX2  =                    1                                                   
 +  CRVAL2  =        1506142847730 / time of first sample derived from sampling 
 +  CDELT2  =           0.01041667 / time difference between two IQ samples in ms    
 +  CTYPE1  = 'CHAN    '           / in Hz                                           
 +  CRPIX1  =                   1.                                                   
 +  CRVAL1  =                    0                                                   
 +  CDELT1  =                    1                                                   
 +  END                               
 + 
 + 
 + 
  
-Following on the area of the head-echo signal there is an area of a static reflection from the meteor trail. Its intensity varies in time. The change in intensity is caused by a progressive recombination of the plasma trail of the meteor and the periodic changes in intensity are caused by a space modulation of the radar signal. 
en/data-outputs.1483641594.txt.gz · Last modified: 2017/01/05 18:39 by fluktuacia