[Lvas] shortwave radio-John Boron

[Rob]

Jay & Annette wrote:
> David, how does having a Shortwave radio help in the occulting asteroid, 
> listening to WWV?  I know WWV has the time measurements, but am curious now 
> as to what's up?  Sorry for the bad pun.  I just recently built a VLF 
> receiver and have another one to build from NASA (INSPIRE project) for 
> listening to the Earth and natural phenomenon.  Jason
>
>   
Jason,

Let me attempt to answer your question.

When observing an occultation, especially if you are alone, it is 
difficult to observe an occultation and look at your watch to get an 
accurate time when the star disappears and then reappears.  With WWV and 
its continuous time hack, you can observe the occultation while 
recording WWV on a voice recorder.  When the asteroid blocks the star, 
the observe announces "Out" loud enough that the recorder picks up the 
announcement with WWV in the background.  When the star reappears, the 
observer announces "Back", again loud enough to be recorded on the 
recorder.  With the WWV time hack in the background, this produces an 
accurate time recording of the star disappearing and reappearing.  
Without an accurate measurement in time, the observation would be 
invalid - not usable for determining the size of the asteroid. 

It is possible to use an atomic watch, but you would have to have 
someone announce the time while someone else is observing.  You can't do 
both by yourself and get an accurate recording of the star's 
disappearance and reappearance.  And there is also no guarantee that 
even atomic watches are on the exact same second of time.  WWV provides 
a constant time hack for all observers that might be observing the 
occultation and contributing their observation data to the research effort.

I hope this quickly answered your question.

Rob Lambert
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