Imaging was done with ASIStudio and stacking using AutoStakkert!3, final editing with CS4. The solar disk is not fully captured, not fitting in the field of view.
Saturday, February 19, 2022
The Sun in H-Alpha
Friday, February 18, 2022
Wednesday, February 16, 2022
First ARISS special digital SSTV experiment testing KG-STV
The first digital SSTV experiment using KG-STV is planned for 20 February 2022 between 05h12 UT and 11h51 UT. This timewindow is for five ISS passes over Europe.
The ISS crossband repeater operates on a downlink of 437.800 MHz. Each transmission sequence will consist of 1m40s transmission, followed by 1m20s pause and will be repeated several times within an ISS pass over Europe.
The used modulation is MSK without error correction. For the decoding of the 320 x 240 pixel image, the software KG-STV is required. The KG-STV software can be downloaded from the following link: "http://amsat-nl.org/wordpress/wp-content/uploads/2022/02/kgstv_ISS.zip"
The ZIP file contains the KG-STV program, an installation and setup manual, some images and MP3 audio samples for your first tests as well as links for additional technical information about the KG-STV use.
After downloading I was able to test the set up using the embedded MP3 file with below result.
KG-STV is an image transmission mode developed by JJ0OBZ in Japan. The mode transmits one 16x16 compressed jpeg block at a time, so that partial transmissions can still reveal the image with missing holes. You can see each block as it's received being reconstructed. The software allows the receiver to send a repeat request in case there are received blocks that have errors. In addition to images, users can send and receive short text messages to each other with this mode.
KG-STV has two modulation modes. MSK (Minimum Shift-Keying) and 4LFSK (4-Level Frequency-Shift Keying). The 4LFSK mode transmits twice as fast as MSK, but is more prone to being affected significantly by propagation effects. Most transmissions are done in MSK mode. Each mode has a choice of convolution encoding or no encoding. The error correction used is Viterbi Encoding (NASA standard K=7 mode)
MSK uses two frequencies, 1800 Hz for 1 and 1200 Hz for 0. For 4L-FSK, '00' 1200 Hz; '01' 1400 Hz; '10' 1600 Hz; '11' 1800 Hz.
All signals operate at 1200 Bd, and occupy a bandwidth of between 500 Hz to 2500 Hz, depending on signal quality.
Sunday, February 13, 2022
Moon Halo or Lunar Halo
This evening the moon is surrounded by a ring, a so called moon halo or lunar halo. The halo is located at a distance of 22° from the center. Image taken with Nikon D7500 10mm f/4.5 ISO400 and exposure time of 8s.
Saturday, February 12, 2022
Expedition 66 MAI75 Feb 2022 - Certificates
Golden Handle with ASI2600MC and Nikon D7500
This evening the "Golden Handle" or "Jewelled Handle according Patrick Moore" is visible on the Moon's disk. The “Golden Handle” effect is produced by way the sun strikes the curved Montes Jura mountain range surrounding Sinus Iridum on the north and west.
Following set up used : TAL200K f/8.5 with Nikon D7500 and TAL 200K f/8.5 with ASI2600MC.
Nikon D7500: ISO100 and exposure time 1/100s. Editing done using CS4.
ASI2600MC: imaging using ASIStudio. Both AVI files and png pictures captured.
- AVI files too large to stack using AutoStakkert!2. Version 3 was downloaden and memory optimized using adaptive buffering. I choose only to stack 5 frames. It took 33 minutes to have a saved result. Stacking was done again without drizzle, resulting in a working time of 20minutes.
- png files are stacked with APP and final editing using CS4. In total 10 pictures, each 52ms, are stacked. This provided the best result.
Tuesday, February 8, 2022
ARISS SSTV – Expedition 66 – MAI-75 February 2022
On Feb 7 & 8, 2022, the Moscow Aviation Institute (MAI) conducted a routine SSTV (Expedition 66-MAI75 Feb 7&8 2022) experiment during orbits that pass within range of Europe and Russia. They typically operate PD120 on a downlink frequency of 145.800 MHz using the Kenwood D710E located in the ISS Service Module. I could download 4 images during 3 ISS passes.
The quality was good but not the synchronisation. I used websdr from Nürnberg http://nbgsdr.ddns.net/
and MMSSTV software.
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