Differences

This shows you the differences between two versions of the page.

--- en:data-outputs [2017/01/05 18:33] – [Spectral records description] fluktuacia
+++ en:data-outputs [2019/02/23 14:50] – fluktuacia
@@ Line 34: / Line 34: @@
 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.
-Following 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.
+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.
+==== 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