Dispersed Radio Transients (DRATS)
Please note that the following information, opinions and conclusion are not commentary on results obtained by other amateurs.
It is to be taken solely as informational about HawkRAO results only.
This project came about as a light distraction from the restrictions on getting 'out and about' due to Covid-19.
Having observed Vela with >98% daily cadence, almost 1300 hours of archived filterbank format data have been accumulated.
What started as basically a programming exercise unexpectedly turned up a significant number of dispersed transients.
This unexpected result set in train a number of investigations to try and identify the origin of these dispersed transients.
Traditionally the presence of dispersion in a transient - where the higher frequencies arrive before the lower frequencies in a transient (pulse) event - is evidence of cosmic origin.
QUOTE: "All bursts from a given source have the same unique value of dispersion measure (DM), or integrated free-electron column density, incontrovertibly distinguishing them from impulsive terrestrial interference. "
While the origin of the dispersed transients seen in HawkRAO archival data will be shown to be almost certainly terrestrial - a number of puzzling features are note-worthy.
The following activities are a rough record of the progress of these investigations which identify these dispersed transients as RFI.
Why 'DRATS' ?
The word 'drat' in English is an exclamation of annoyance or disappointment - which fits both a nice acronym for 'Dispersed RAdio TransientS', but also an apt description of the frustrating nature of RFI.