Plotting antenna pattern from Sun noise
 

For those interested in confirming beamwidth of a large aperture dish at
microwave frequencies, the following article describes a method using Sun
noise as a measurement source:
http://www.vk1od.net/nfm/application...ernFromSun.htm .

Owen

Plotting antenna pattern from Sun noise
 

"Owen Duffy" wrote in message
...
For those interested in confirming beamwidth of a large aperture dish at
microwave frequencies, the following article describes a method using Sun
noise as a measurement source:
http://www.vk1od.net/nfm/application...ernFromSun.htm .

Owen

Hi Owen,
I have done this to plot the pattern of my 1296 14' EME dish- using both a
GR1236 meter and more recently with an SDR-IQ receiver on the output of my
transverter.

Dale W4OP

Plotting antenna pattern from Sun noise
 

"Dale Parfitt" wrote in
news:%mfRi.4787$GR1.4045@trnddc08:

Hi Owen,
I have done this to plot the pattern of my 1296 14' EME dish- using
both a GR1236 meter and more recently with an SDR-IQ receiver on the
output of my transverter.

Hi Dale,

Interesting.

I should have noted in the article that Rex's measurements were made with an
ordinary SSB transceiver (behind a transverter), the same receiver that is
used for normal QSOs.

Owen

Plotting antenna pattern from Sun noise
 

On Oct 16, 6:10 pm, Owen Duffy wrote:
For those interested in confirming beamwidth of a large aperture dish at
microwave frequencies, the following article describes a method using Sun
noise as a measurement source:http://www.vk1od.net/nfm/application...ernFromSun.htm.

Owen

The Altitude and Azimuth of the Sun or Moon During One Day application
is located at the following URL:

http://aa.usno.navy.mil/data/docs/AltAz.php

The site can also be reached as follows: Access the U.S. Naval
Observatory Home web site (at http://www.usno.navy.mil/ ); at the menu
of the left of this home page select the Astro Applications entry.
From the Astro Applications web page, select the Data Services entry.
From the Data Services web page, select Altitude and Azimuth of the
Sun or Moon During One Day.


I hope this may prove useful.


Jimmie

Plotting antenna pattern from Sun noise
 

JIMMIE wrote in
ps.com:

On Oct 16, 6:10 pm, Owen Duffy wrote:
For those interested in confirming beamwidth of a large aperture dish
at microwave frequencies, the following article describes a method
using Sun noise as a measurement
source:http://www.vk1od.net/nfm/application...ernFromSun.htm
.

Owen

The Altitude and Azimuth of the Sun or Moon During One Day application
is located at the following URL:

http://aa.usno.navy.mil/data/docs/AltAz.php

The site can also be reached as follows: Access the U.S. Naval
Observatory Home web site (at http://www.usno.navy.mil/ ); at the menu
of the left of this home page select the Astro Applications entry.
From the Astro Applications web page, select the Data Services entry.
From the Data Services web page, select Altitude and Azimuth of the
Sun or Moon During One Day.


I hope this may prove useful.

My article contains links to two spreadsheets, a basic one and an
enhanced one. The enhanced one contains macro functions that calculate
the Sun's position from the time data recorded by NFM (and your location
data). Of course, you need to make sure your computer clock is
syncronised before taking the measurements. The link to the enhanced
spreadsheet is in the Links section of
http://www.vk1od.net/nfm/application...ernFromSun.htm .

The spreadsheet uses a set of macro functions derived from the NOAA
calculator ant published by the Department of Ecology, Olympia WA.

Owen

Plotting antenna pattern from Sun noise
 

"Owen Duffy" wrote in message
...
JIMMIE wrote in
ps.com:

On Oct 16, 6:10 pm, Owen Duffy wrote:
For those interested in confirming beamwidth of a large aperture dish
at microwave frequencies, the following article describes a method
using Sun noise as a measurement
source:http://www.vk1od.net/nfm/application...ernFromSun.htm
.

Owen

The Altitude and Azimuth of the Sun or Moon During One Day application
is located at the following URL:

http://aa.usno.navy.mil/data/docs/AltAz.php

The site can also be reached as follows: Access the U.S. Naval
Observatory Home web site (at http://www.usno.navy.mil/ ); at the menu
of the left of this home page select the Astro Applications entry.
From the Astro Applications web page, select the Data Services entry.
From the Data Services web page, select Altitude and Azimuth of the
Sun or Moon During One Day.


I hope this may prove useful.

My article contains links to two spreadsheets, a basic one and an
enhanced one. The enhanced one contains macro functions that calculate
the Sun's position from the time data recorded by NFM (and your location
data). Of course, you need to make sure your computer clock is
syncronised before taking the measurements. The link to the enhanced
spreadsheet is in the Links section of
http://www.vk1od.net/nfm/application...ernFromSun.htm .

The spreadsheet uses a set of macro functions derived from the NOAA
calculator ant published by the Department of Ecology, Olympia WA.

Owen

Hi Owen

I use a free program "APTDecoder" for monitoring satellite location.
That program includes a "Flat Earth Monitor" in which the Sun and Moon are
shown. A "mouse pointer" on either the Sun or Moon will give the location
and Az-El from your location, in real time. I have never used the data to
point my dish, but, if the data is erroroneous, Id like to know where is
wrong so it can be made better.

Jerry

Plotting antenna pattern from Sun noise
 

"Jerry Martes" wrote in
news:cnwTi.7489$0l4.1447@trnddc08:

....
location and Az-El from your location, in real time. I have never
used the data to point my dish, but, if the data is erroroneous, Id
like to know where is wrong so it can be made better.

Jerry, I have no knowledge of the program you speak of, and cannot comment
on its accuracy.

Owen

Plotting antenna pattern from Sun noise
 

"Owen Duffy" wrote in message
...
"Jerry Martes" wrote in
news:cnwTi.7489$0l4.1447@trnddc08:

...
location and Az-El from your location, in real time. I have never
used the data to point my dish, but, if the data is erroroneous, Id
like to know where is wrong so it can be made better.

Jerry, I have no knowledge of the program you speak of, and cannot comment
on its accuracy.

Owen

Hi Owen

The APTDecoder program is written by Patrik Tast who lives in Finland.
The main reason for anyone using the program is to decode NOAA weather
satellite signals so images of the satellite's view of the Earth, from orbit
can be displayed on computers by amateurs (in real time).
I mentioned the "Flat Earth Monitor" in Patrik's program because it seems
to always be a source of Az-El and Lon-Lat for Sun and Moon position. You
tell the program where you are and the program tells you where to point. I
mentioned the "accuracy" because he is interested in knowing about any
improvements he can make to his program. Patrik does not charge for his
program. He is an amateur, interested in providing good data, and I
consider you to be a good critic.

Jerry

Plotting antenna pattern from Sun noise
 

"Jerry Martes" wrote in
news:QFxTi.27907$DX.11271@trnddc06:

does not charge for his program. He is an amateur, interested in
providing good data, and I consider you to be a good critic.

Hi Jerry,

That is flattering, but undeserved I am sure.

There are a lot of calculators on the 'net for giving the Sun's position
at a place and time, and they use varying algorithms for more or less
accuracy.

The routines I used in the spreadsheet were unashamedly the work of some
one else, the chap who converted them to VBA and the original NOAA
javascript routines behind their page at
http://www.srrb.noaa.gov/highlights/sunrise/azel.html . I have accepted
they were good enough for my application, and they seemed quite close to
another navigator application that I have.

Owen

Plotting antenna pattern from Sun noise
 

Owen Duffy wrote:
"Jerry Martes" wrote in
news:QFxTi.27907$DX.11271@trnddc06:


does not charge for his program. He is an amateur, interested in
providing good data, and I consider you to be a good critic.


Hi Jerry,

That is flattering, but undeserved I am sure.

There are a lot of calculators on the 'net for giving the Sun's position
at a place and time, and they use varying algorithms for more or less
accuracy.

The routines I used in the spreadsheet were unashamedly the work of some
one else, the chap who converted them to VBA and the original NOAA
javascript routines behind their page at
http://www.srrb.noaa.gov/highlights/sunrise/azel.html . I have accepted
they were good enough for my application, and they seemed quite close to
another navigator application that I have.



And, really, what precision do you need for pointing/plotting?

Presumably folks are looking at fairly wide beamwidths (so that the sun
size (1/2degree) is a small fraction of the beamwidth)
5 degrees?
1 degree?

Get into that 1 degree range and you need to start taking into account
stuff like the non-spherical earth, and stuff like the sun's apparent
diameter (which is different for radio and visible light, as well as
varying with the distance).

Heck, you might have to worry about whether your local gravity vector
(presumably what you used to set the elevation zero point) is
perpendicular to the geoid surface used for the look angle calculation.
And, whether your zero az is actually the same north as used in the look
calculation (as opposed to, say, aligned to Polaris at some arbitrary time)

(FWIW, the calculations behind the USNO page do take a lot of this stuff
into account)

Owen