[amsat-bb] SSTV SpaceCam News

MM ka1rrw at yahoo.com
Tue Jul 13 19:53:15 PDT 2010

ISS Amateur Radio Status: July 13, 2010

SpaceCam planed for July 15-16
By Miles Mann WF1F,

MAREX-MG News	www.marexmg.org

Manned Amateur Radio Experiment

Hi everyone:

Notes from the Ariss blog
MAI-75 activation planned for July 15-16 (updated)
An activity to support SSTV activation (MAI-75) has been schedule on July 15 and 16. Times fall between 12:00-15:00 UTC on the 15th and 10:00-12:00 UTC on the 16th . 
The system will be operating space cam in slide show mode and is expected to use the Martin 1 format. The times are just over 1 orbit each day (two passes over Moscow) so opportunities will be very limited.

That’s good news, it has been a while since we have had the Marex SpaceCam1 project on the air.

Note to ARISS and Sergej Samburov:
Slide Show Mode recommended Settings:
Kenwood TM-D700 Transmitter power set to Low/5 watts.
Image Delay setting 3 or 4 minutes.
Image Mode Recommendation, Robot-36
Keep the radio in a well-ventilated area.

The reason Marex recommends Robot-36 over the Martin-1 or Scotty imaging modes is because of the transmission time required to complete an image.  The lower quality image Robot-36 only requires approximately 40 seconds of transmission time to complete (Image time plus CW Id, etc).

A Martin-1 image, which is higher quality, requires 114 seconds.
Since all electronics run hotter in space, we need to make sure we do not overheat the TM-D700 again, as happened before in August 2006.

Terrestrial testing has shown that SpaceCam running slide show mode at 5 watts, Robot-36, and a 3-4 minute image delay will give us the most images, with an acceptable amount of heat loading on the Kenwood TM-D700.
If Martin-1 is required, then the delay between images will need to be increased to 8-10 minutes between images, to allow the TM-D700 time to cool down.

Optional Turbo Fan project for cooling the TM-D700

Tips for Working Slow Scan TV:

Will I be able to receive images from SpaceCam1?

Yes!  SpaceCam1 will transmit and receive images on amateur radio frequencies, using standard SSTV formats.  Although SpaceCam1 is capable of operating in several modes, the recommended format while in Slide Show mode is Robot 36.  This format offers the best standard compromise between image quality and transmission time and heat stress.

In addition to two-way "interactive" operation, SpaceCam1 provides the following fully automatic functions:

 Transmission from a live camera or disk at specified intervals 
 “Slide Show" operation from a set of images stored on the system 
 SSTV Repeater

What equipment will I need to receive the images?

Radio receiver with an outdoor antenna.  The radio receive will need to be able to receive FM signals on 145.800 MHz radio band.
A PC with SSTV software or a dedicated SSTV scan converter. 

For information on how to receive SSTV images from the International Space station, check out the MAREX link:

Over the next few weeks we maybe receiving images from the International Space station via Slow Scan TV (SSTV). The MAREX team will be collecting these images from the amateur Radio and SWL community and we will post the best.

We would like to collect all images received. However in order to properly catalog the images we request you use the following image naming format.
After you receive you images; please rename the images using the following format, All Lower case letters

Year 06, Month 07, Day 31,  (UTC time), Call sign,
Short text description, .JPG


New format:

I removed the first two numbers of the year and the “Z” for UTC time.
All dates are assumed to be in UTC dates. The images coming down from ISS will also have a time stamp embedded into the image. You can also use these numbers to generate you file names.  If you are a Short Wave listener and do not have a call sign, just place your Initials after the time (0607311905abc.jpg)

If we break this down 
Year =06
Month = 07
Day = 31
Time = 1905 UTC
Call sign = wf1f
Description (optional) = Windows shot
Image format = jpg

Image Quality
Please do not put any text over lays on the images, Example, do not put web page or advertisements in the image. Your own call sign and date are acceptable.  

Send all images directly to MAREX at
Marexmg at comcast.net

We would also like to know the following information in your email.

Name or Call sign
Country / State
Software decoding tool
Elevation or range of ISS when you decoded the image.

Slide Show Mode:
The MAREX SpaceCam1 software contains a feature called “Slide Show” mode. It allows the crew to preload a directory full of images that will be automatically transmitted to Earth. The crew will not need to keep pushing a button to send images. In theory the system can run for weeks at a time without crew involvement. The SpaceCam project will be able to transmit over 200 SSTV images per day (Robot 36 format).

Ariss has not announced any plans for a SSTV Uplink frequency.

SSTV Decoding Software

There are many choices in SSTV software, some Free, others with more features cost a few bucks. 

So have fun, find your best setup and start practicing (on Earth) how to decode SSTV on 2-meters.

Marexmg Web page

ARISS Web page and other great Space projects

73 Miles WF1F MAREX-MG

Until we meet again



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