A lot of interesting details (and photos) about the onboard TV-photo system of the Lunokhod-1 could be found on [1].
Btw, it looks like the tapes indeed may contain the photos - the session dates seem to coincide with taking of panoramic shots, according to the official news coverage of the mission (mentioned earlier). Moreover, the red "Ст." marks on the tape cover might just point to the "Stereoscopic" shots, which are produced by the cameras 2 and 4 (left-right pan). This also explains the "even" remark on the tape cover.
Also, the narrator mentions that the recording was done directly from FT console (Photo-Television), likely post-factum (??for lab analysis/enhancement).
Wikipedia has a nice photo of the Control indication panel [2], the "ФТ" panel lights are on the right edge. There you could also spot SKU lights ("СИСТЕМА КУРСОУКАЗАНИЯ", Course Guidance System) on the left bottom. Lights for RIFMA were likely on the bottom edge in Scientific Instruments group (covered in the photo by a description plaque).
Fun to learn about this. Thank you for the "journey"! It was truly a great achievement not just for people of USSR, but for the whole humankind. Hopefully, given the recent declassifying of some of the Soviet space-programs, it might be possible that there could be already available the images of the very panoramas possibly contained on the tapes (matching by the session dates).
Anybody knows of any online archives of images taken by Lunokhod-1? ...Well, answering it by myself: [3] is an excellent selection of historic shots of Moon from Soviet exploration efforts, lots of technical info about cameras and signals.
> ...it might be possible that there could be already available the images of the very panoramas possibly contained on the tapes (matching by the session dates).
Indeed, an exhaustive set of scans of Lunokhod-1 panoramas has been published recently by the Laboratory for Comparative Planetology. Lunar mission Day 5 (Lunation 5) panoramas are at [1].
There were reported total 16 panoramas made during Lunar mission Day 5 (March/9-20/1971, 12 days); last one - during the session 8 (see [2], Lunation 5. Session 8. Panorama 16).
Assuming the session/seance number coding is [Lunar-day][session], session-code 508 corresponds to Lunar-day:5, session:8. That is possibly no more reported panoramas in the remaining sessions of the Lunar day.
One of the tape in question contains sessions 509, 512, 515. Thus there might be no more reported/published panoramas on that tape.
However, the audio fragment given (?session 509), annotates it as "continuation of session 508". Perhaps it may have some additional panorama data for the 8th session panorama.
As for the other tape, it's during Lunar mission day 7 (May/7-15/1971, 9days). Total number of panoramas reported for this period is 21; last made during session 8.
So, similarly, the other tape (for the session 709) may just have either no more panoramas or some additional data for the panorama taken during session 708.
Anyways, hopefully the "buzzing" as heard on the sample will be decoded to reveal something interesting.
Good luck!
P.S. Btw, the reason the tape sample sounded in reverse may be because it was played on the wrong side. Perhaps it should have been rewound prior to the replaying. Meanwhile, the other tape has a remark on it "Перемотана" (Rewound).
>... However, the audio fragment given (?session 509), annotates it as "continuation of session 508". Perhaps it may have some additional panorama data for the 8th session panorama.
Relistening to the sample, it appears that narrator announces turning ON the RIFMA just before the supposed data signal begins. I would rather interpret this data as relating to the spectral analysis of the Lunar soil, not the panorama data stream.
Both feeds supposedly use the same transmission system. RIFMA signal is modulated in the same way as the signal from cameras 1 and 4 (which could be sent simultaneously on separate sub-carriers).
On reception the signal is filtered, demodulated, and then recorded (including onto the magnetic tape). This means that the signal we hear on the sample has been already demodulated and probably represents some kind of bit-stream. The panoramas were also recorded onto thermal paper, akin Fax, not necessarily with the same protocol though.
Panorama data is known to be transmitted at 4 lines/sec, each (vertical) line is 500 pixels. So the bit rate could be around 500 x pixelbits x 4=2000 x pixelbits per sec. There should likely be some control bits.
The 4 minute sample chunk then would contain around 240 x 2000 x pixelbits of data (960 lines). Assuming 8-bit pixels, this yields about 450KB. However, it as well could be 1-bit black or white.
If indeed it's RIFMA data, then it's hard to guess the data format. In case of panorama data, at least there's a chance of simply interpreting it as a stream of intensities.
This also leaves open the question of determining the 0/1 encodinng in the recorded "audio" signal (? Freq/delay modulation)
Also the sample appears to be essentially mono doubled to both channels, instead of data and narration on separate tracks as supposedly is on the tape. This bleeds the hum and buzz ?from the narrator's mic onto the data feed.
Perhaps you could re-record the tracks/channels separarely for better chance at the data track analysis.
>... One of the tapes in question contains sessions 509, 512, 515. Thus there might be no more reported/published panoramas on that tape.
The notes sheet in Fig. 10 of your blog page are obviously related to the session 512 (mentioned in the notes and also visibly marked 512 on the back side).
According to the outlined status for the beginning of the session 512, it's stern away from/off Sun, without SKU, without TM, without panorama, with RT.
That is, the RT (Roentgen telescope) is on. So possibly the contents of the session 512 is relating to the reception of RT imaging data.
Btw, it looks like the tapes indeed may contain the photos - the session dates seem to coincide with taking of panoramic shots, according to the official news coverage of the mission (mentioned earlier). Moreover, the red "Ст." marks on the tape cover might just point to the "Stereoscopic" shots, which are produced by the cameras 2 and 4 (left-right pan). This also explains the "even" remark on the tape cover.
Also, the narrator mentions that the recording was done directly from FT console (Photo-Television), likely post-factum (??for lab analysis/enhancement).
Wikipedia has a nice photo of the Control indication panel [2], the "ФТ" panel lights are on the right edge. There you could also spot SKU lights ("СИСТЕМА КУРСОУКАЗАНИЯ", Course Guidance System) on the left bottom. Lights for RIFMA were likely on the bottom edge in Scientific Instruments group (covered in the photo by a description plaque).
Fun to learn about this. Thank you for the "journey"! It was truly a great achievement not just for people of USSR, but for the whole humankind. Hopefully, given the recent declassifying of some of the Soviet space-programs, it might be possible that there could be already available the images of the very panoramas possibly contained on the tapes (matching by the session dates).
Anybody knows of any online archives of images taken by Lunokhod-1? ...Well, answering it by myself: [3] is an excellent selection of historic shots of Moon from Soviet exploration efforts, lots of technical info about cameras and signals.
[1]:https://www.kik-sssr.ru/Lunohod-1.htm (in Russian)
[2]:https://ru.m.wikipedia.org/wiki/%D0%9B%D1%83%D0%BD%D0%BE%D1%...
[3]:http://mentallandscape.com/C_CatalogMoon.htm