Multifrequency Study of Giant Radio Pulses from the Crab Pulsar with the
  K5 VLBI Recording Terminal
  Simultaneous multifrequency observations of the Crab pulsar giant pulses
(GPs) were performed with the 64-m Kalyazin radio telescope at four frequencies
0.6, 1.4, 2.2 and 8.3 GHz using the K5 VLBI recording terminal. The K5 terminal
provided continuous recording in 16 4-MHz wide frequency channels distributed
over 4 frequency bands. Several thousands of GPs were detected during about 6
hours of observations in two successive days in July 2005. Radio spectra of
single GPs were analysed at separate frequencies and over whole frequency
range. These spectra manifest notable modulation over frequency ranges,
$\Delta\nu$, both on large ($\Delta\nu/\nu\approx 0.5$) and small
($\Delta\nu/\nu\approx 0.01$) frequency scales. Cross-correlation analysis of
GPs at 2.2 GHz showed that their pulse shapes can be interpreted as an ensemble
of unresolved bursts grouped together at time scales of $\approx 1$ mcs being
well-correlated over a 60-MHz band. The corresponding GP cross-correlation
functions do not obey the predictions of the amplitude-modulated noise model of
Rickett (1975), thus indicating that unresolved components represent a small
number of elementary emitters.
