Radio Interferometry

Failure to detect solar interferometric fringes at LRO, Lichfield, UK, 13-15/8/2024

Calculating expected fringe period of interferometric solar traces, if detected (c/o Mike Otte, SARA):

Fringe rate = Baseline / wavelength *angular rotation of earth * cos declination

ex: Fringe period = (44.2 M / .21M * 7.3 x 10 -5 * cos 40)-1 = 84.96 sec  

Sun is at 14 degrees Declination

Your at 53 deg latitude

What is your baseline spacing?  At LRO, baseline spacing between aerials is 5m.

Mike Otte’s calculations of expected fringe periods for baseline spacing of 10m:

 296 sec =FP=(10M/.21M* 7.3 x 10 -5 * cos 14)-1 

296 /60 = 4.94 minutes   for 10 Meter baseline

Mike Otte’s calculations of expected fringe period for baseline spacing of 5m:

592 sec =FP=(5M/.21M* 7.3 x 10 -5 * cos 14)-1 

592 /60 = 9.88 minutes   for 5 Meter baseline.

Determining where to look for this fringe space on graphs on attached Excel workbook:

My 2 x Nooelec 1.4 GHz aerials point 163 degrees = time each day 12:27 BST (11:27 UTC) from LRO location.

Conclusion from my data 13-15/8/2024 = no clear different traces at that time hence I have NOT detected solar interferometric fringes.

I believe that level of interference is just too great from LRO backyard location.

During the two days of this measurement 13-15/8/2024, no one went into my backyard to introduce interference, large amounts silver foil wrapped around receiver and more as barrier between receiver and PC to reduce interference.

Andy

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.