Some stuff about BAA-seminar GSR

[Stephen Arbogast]

I have been using it  with some  success... question.. is   decln really altitude-latitude ?

[Marcus D. Leech]

On 2025-09-09 23:12, 'Stephen Arbogast' via Society of Amateur Radio Astronomers wrote:

I have been using it  with some  success... question.. is   decln really altitude-latitude ?

Elevation = 90° - (Latitude - Declination)

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[Stephen Arbogast]

I  get  different  results  using    ezRA..   compared to  GSR  from Marcus  Leech..... according  to my iphone  my  discovery  dish is pointed  at  60.5  degrees   elevation   where  my results  are 7.5   declination    but  with  GSR  from  Marcus  Leech  my declination  is  about  23   degrees......  so  what is  going on here? My  latitude is    about  37 degrees  North  and  longitude   is  about   107  degrees    West  my  altitude  is   about    1992 meters.

I need  to look  into conversion  of  coordinates   systems..

[Stephen Arbogast]

Oh  .. thank you!

[Alex P]

Try taking drift scans +-  several hours about 10:30 PM EDT @ + 3 deg N of Overhead for you = Declination + 40 dg

Set the 'frame' rate to save files @ 1 degree increments in RA  ( 4 minutes time )

[Stephen Arbogast]

Yes,    I am doing    drift scans  and  getting  some  results  now   with  Marcus  Leech's   GSR ...   but  it is  getting   cold  at night  now  here in  South West Colorado. My  neighbors are   running  inverters    from  solar panels  and   batteries.....    I find it  difficult  to record total power   measurements due to  RFI.

Your  plot  is  very  cool!

I  don't think  I will  ever  come close  to a  plot  like  the one  you  sent.  I am using   a  Discovery  Dish   which is minimal.    I have  found  that my  AirSpy  is very  stable inside  my work area.   I kind of  think  the  lna  in  my  Discover Dish is   fairly  stable...    the  only time I see usual  noise  power  rise   is  when the  sun  comes close to crossing  in  front  of the  beam of my dish.

A  far as I know Ted Cline  is  still  working  on his  project    to make an ezCol  version  based  on GNU Radio .  I  totally  support  this..   GNU Radio  has  built in  ring  buffer  management   and  scheduling   management  for the   flow graphs... cool stuff!

Stephen

[b alex pettit jr]

Try extending the sides of the front reflector to act as an RFI Shield .. just to compare    

When I was trying to improve the WiFi dish, my 'theory' was : 

     " If I can see the feed with my eye, an RFI source from that direction can also "  

           &   that was successful.

Alex

[Stephen Arbogast]

I think  I am onto a solution....     I have  been collecting  data  using  Marcus  Leech's  GNU Radio  Spectrometer  with ezRA  vector  logging.   I have been   doing    24 hr  scans  using  an  AirSpy  with  GRC's  SOAPY  driver  ( which is  marked  as  deprecated in GRC  Companion).  Usually the  output of total power  drops  to zero  within 3 hours. Sometimes it recovers, some time  it  does not.

I am now  collecting data  using  the  same software  but with  my  RTL-SDR V3... and  so far so good...   smooth and consistent.   See  screen shot.

So, I am thinking  the SOAPY   driver for  AirSpy in  GNU Radio  Companion is not  trustworthy.