[TCRA] Slow scan TV images from the ISS this coming weekend

Rodney Anders wb9wkt at gmail.com
Thu Dec 24 06:47:23 CST 2015


Looks like this coming weekends ISS SSTV has been postponed.

"SSTV event now targeting mid January. More details as the become available
from the Russian team. #*ARISS"  (on twitter)*
<https://twitter.com/hashtag/ARISS?src=hash>


wb9wkt

On Sun, Dec 20, 2015 at 9:22 AM, Rodney Anders <wb9wkt at gmail.com> wrote:

> Hello:
>
>      Just want to let people know that the ISS (international space
> station) may be sending slow scan images down to earth on Dec 26 and Dec
> 27.  You can record these passes then play them back by your computer
> microphone and see what pictures were being sent down.
>
>  All you need to do is monitor 145.800 and record the noise.  Then take it
> inside and play it back by your computer program or app.
>
>  Looking at the PASSES it will be during the day---which is way cool.
> (see the pass schedule below)
>
>    The web will have a ton of information on all of this but here is a
> quick list:
>
> Program to decode:  I downloaded "MMSSTV" works slick.
> Mode they use:          PD120
> Freq to monitor:         145.800
>
> I have also included the times of the passes this weekend along with a
> brief write up of what might happen.  Sounds like its not 100% sure to
> happen.
> Its pretty cool to think we can capture images from the ISS which is
> moving 17,000 mph.
>
> Give it a try--if you have any questions email me back.
>
> Rodney Anders
> wb9wkt
>
> What to expect during a pass
>
> SSTV mode PD120 will be used instead of PD180 which was used during
> previous SSTV events this year. With PD180 it takes about 3 minutes to send
> an image. With PD120 it takes about 2 minutes to send an image. Since
> images transmitted with PD120 take less time to send than with PD180, more
> images can be received during a single ISS pass.
>
> An ISS pass that goes right overhead (90 degrees elevation), lasts about
> 10 minutes. ISS SSTV transmit time and off time are usually setup to
> provide the radio with a 50% duty cycle (only transmit half the time so the
> radio doesn’t overheat). With image transmission taking two minutes, off
> time will probably be two minutes as well.
>
> Compared to previous SSTV events using PD180, this means it should be
> relatively easy to receive at least two complete images in one pass, with
> the possibility to receive up to three images if timing, conditions, and
> setup are ideal.
>
> When the ISS comes into view/has line of sight with you, this is known as
> Acquisition of Signal, or AOS. The ideal situation for a high elevation 10
> minute pass would be if the first image started transmitting exactly at
> your AOS, and you had a directional antenna so you could receive the signal
> even while the ISS was very low in the beginning and end of the pass.
>
> In this case you would be able to receive three images like this:
>
> minute, image TX/off
> 0-2, complete image 1
> 2-4, off
> 4-6, complete image 2
> 6-8, off
> 8-9, complete image 3
>
> The more common situation will be that the first image transmission will
> start either before or after AOS. In this case you will only have the
> opportunity to receive two complete images, but this is still twice the
> amount of images that were possible with PD180. The downside is the image
> quality is not as high as with PD180.
>
>
>
>
>
> 25 dec -        16:36:16    10°    WNW        16:39:29    52°    SW
> 16:42:42    10°    SE    daylight
> 26 Dec    -    09:17:38    10°    S            09:19:42    16°    SE
>   09:21:51    10°    E    daylight
> 26 Dec    -    10:52:32    10°    WSW    10:55:47    77°    NNW
> 10:59:04    10°    ENE    daylight
> 26 Dec    -    12:29:43    10°    WNW    12:32:35    27°    N
> 12:35:26    10°    NE    daylight
> 26 Dec    -    14:06:44    10°    NW        14:09:38    28°    N
> 14:12:33    10°    ENE    daylight
> 26 Dec    -    15:43:04    10°    WNW    15:46:22    89°    NNE
> 15:49:40    10°    ESE    daylight
> 26 Dec    -    17:20:35    10°    W            17:22:24    14°    SW
> 17:24:08    10°    SSW    visible
> 27 Dec    -    09:59:25    10°    SW         10:02:38    61°    SE
> 10:05:52    10°    ENE    daylight
> 27 Dec    -    11:36:13    10°    W            11:39:13    32°    NNW
> 11:42:14    10°    NE    daylight
> 27 Dec    -    13:13:28    10°    NW         13:16:15    25°    N
> 13:19:03    10°    ENE    daylight
> 27 Dec    -    14:49:54    10°    NW         14:53:09    54°    NNE
> 14:56:23    10°    ESE    daylight
> 27 Dec    -    16:26:38    10°    W            16:29:24    25°    SW
> 16:32:08    10°    SSE    daylight
>
> How to read this.
>
> December 26 @10:52:32 the ISS will be on the WSW horizon.  At 10:55:47 it
> will be 77 degrees in the NNW  (0 degress is the horizon and 90 degress is
> straight over head).  Then at 10:59:04 we will lose the signal in the ENE.
>
> You can use a hand-held----point your radio WSW then when you hear it you
> can track it.  When the signal starts to get fuzzy you need to point your
> radio to the path.  it goes WSW-------NNW--------ENE  in about 8 minutes of
> time.
>
>
> Let me know if you have questions.
>
> Rod
>
>



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