Modeling the periodicity's caused by the aerostat radar

Comparing the periods from the model and P2030 data (.ps)  (.pdf)
aeroPer.dat...file containing aerostat periods.

        The aerostat is a tethered balloon radar that flies above lajas puerto and is used for drug interdiction (more info).  A model was made of the aerostat radar total power output received at the observatory. The model was then used to determine the periods that it could generate in pulsar observations.  The model used the following parameterization of the radar:

    The model creates a 12 second stretch of radar data (total power vs time) at 1 usecond time resolution. This is  1 rotation of the radar with 12000000 samples.

Comparing the model data with the pulsar data

     The periodicity's in the aerostat model data was compared with the periodicity's found in the total power time series of p2030 pulsar data (100 Mhz bw centered at 1420 Mhz with 64 usecond sampling). 12 seconds of data was fourier transformed and then then the magnitude was computed. The comparison was made with the full model, and a version of the model with no blanking, sidelobes, or gaussian beams.
    The aerostat radar was outside the rf band of p2030, but the data was taken when the 10db amplifier for the filter bank was installed (08apr05 thru 12apr05). This amplifier caused the system to go into compression when the radar pulse was on.
    The plot compares the  spectra computed from the total power time series for the model and p2030 data (.ps) (.pdf): The blanking causes  sinx/x nulls spaced at .17 hz. The sidelobes cause nulls spaced at .46 hz. The first nulls lines up with the pulsar data, the second null of the full model doesn't. This is probably because the pulsar data is only seeing compression of the system and the sidelobes may not be strong enough to drive the system into compression. But the pulsar data is definitely seeing the blanking.

List of  periods from aerostat data.

    The bottom plot shows the periods and relative amplitudes from the model for periods with amplitudes down to 10% of the maximum.  Multiple periods caused by the sinx/x have been grouped with the peak amplitude near that region. You can get a list of these periods from the file aeroPer.dat.

The model can be asked via the idl routine:

processing: usr/p2030/rfirdr/aero/