Mouse over the spectrogram to read out frequency and time
Draw box over the spectrogram to measure signals
Filtered bearings interactive narrow band spectrogram.
Raw spectrum data from the 3-axis receiver at Todmorden is downloaded
from abelian.org and the spectrogram and bearing calculations are done by
your browser. This enables the spectrogram to be more interactive than
other web-based spectrograms.
In this unique display mode, the bearing of each bin is calculated and
only those bins which fall within +/- 20 degrees of
your compass setting are displayed.
This is a standard cardioid response with a good null in the
reverse direction. It is optimum for searching for weak signals in the
presence of strong off-beam noise. You usually have to point the cardioid
pattern away from the great circle to obtain the best S/N.
This is a special omni-directional display mode, special in that
each bin has its own cardioid response calculated. The result is the
sensitivity of a cardioid combined with omni-directional response.
Vertical E-field only. This gives a true omni-directional response
but doesn't have the S/N sensitivity of the Omni mode.
H E/W and H N/S:
The display uses one or the other magnetic field component.