NOAA Decoding

[wx2watch]

Not everyone has the space for special antennas or is simply not allowed to set them up (prohibited by the landlord).
I only have a Diamond X-30 that I use for receiving the NOAA satellites. Of course, the results are not 100%, but I think they are quite impressive. Of course, there is always a better way, but then the question is "how high is the effort and how much money do you have to spend".

Very nice indeed for a “non-specialized” antenna!! (Wish I had those results when I first started back in the 80’s – my rabbit ear antenna results convinced me to try building a helical.)

And, YES, there are many perspectives regarding time, effort, and money to achieve a given result!

Not trying to be a snob, but once again I am impressed with the results by other fellow amateurs! Also, I know the pain of living with an HOA especially after living in a rural area for 15+ years with my own “antenna farm.”

For instance, I’m now in an urban environment with a HOA - for the last 5 years I have been forced to throw all my gear into the back of my pick-up truck and find a “big box” store’s parking lot to setup in when I have the urge for an APT session. Needless to say, this has severely limited my monitoring – mostly a fair weather activity nowadays.

The compact QFH antenna is a miracle for this use although I sometimes get some funny looks from passersby…

So, in conclusion, we all have to start somewhere but no telling where the passion will take you.

 

[PDXh0b0]

As dlwtrunked indirectly alluded to, a simple whip antenna (even if cut for 137 MHz) will not do the proper job of receiving the APT signal. The APT signal uses circular polarization. (I do not recall which flavor of circular for APT, either right handed (RHCP) or left handed (LHCP)).

A simple whip antenna is going to be either horizontal or vertical polarization, either of which will give poor results for APT service.

IIRC, the APT antenna must either be physically similar to the wave form (e.g. omni-directional QFH antenna) or helical (VERY directional antenna). The linear looking v-dipole antenna achieves this by a bit of electro-mechanical phase trickery.

Some combinations just seem to work, here this person gets great images with a discone

 

[krokus]

I'm a bit late to this thread, but there was an article series on building an Lindenblad antenna just for APT reception. It was in Electronics Australia, in the June, July, & August 1992 editions, authored by Tom Moffat VK7TM, now a SK.

 

[g6zru]

Spartanman.
Have a look at this site; www.vinnant.sk/. The 137mhz turnstile is what I use as I'm useless at DIY! It gives good results, is well constructed and good value for the money (in fact I have just orded another for use with Meteor.).

Fred

 

[K5MPH]

Here is a easy Diy antenna rtl-sdr.com/simple-noaameteor-weather-satellite-antenna-137-mhz-v-dipole

 

[TexTAC]

This thread just got me interested and I am going to give NOAA weather map decoding a shot using the radio and antenna I already have. What is the best software to use to decode in realtime from a Yaesu 991A reciever? Also can one software program decode both the NOAA and METEOR satellites?

 

[wx2watch]

This thread just got me interested and I am going to give NOAA weather map decoding a shot using the radio and antenna I already have. What is the best software to use to decode in realtime from a Yaesu 991A reciever? Also can one software program decode both the NOAA and METEOR satellites?

I was hoping someone else would chime in to answer your questions. However, I’ll take a whack at it…. But first, a comment or two.

When you say NOAA weather map, I think of the HF “fax” (NAVTEX) service from the United States Coast Guard. This is available at 518kHz and HF utilizing SITOR encoding scheme. (If you go the USCG Navcenter web site, they have real-time examples of their broadcast products.) You can probably pick this service up with your existing radio and external antenna.

However, I think you probably are referring to NOAA’s APT service (pretty pictures from polar orbiting/ Low Earth Orbit satellites) available on the old NOAA/Tiros-N satellites several times a day. This is an analog ~136 MHz FM signal that requires a “band width” of approximately 38 kHz. (Also, a circular polarization antenna is desirable but don’t get me started on that topic (ha, ha))

The Russian METEOR LEO satellites (when they are working…) broadcast a digital VHF signal called LRPT – Low Resolution Picture Transmission service.

By the way, this LRPT service is also available from the “new” generation of NOAA JPSS satellites at X-band ~8GHz but that is a discussion for another day!

And just to complete the survey – LRPT is also available on L-band from the US Geostationary satellites (GOES).

As for software - I use Wxtoimage for analog APT service. I personally can’t recommend any software for LRPT but a Google search should give you an answer.

 

[TexTAC]

Thank you. I may try out the wxtoimage software just to see what happens with my current setup.