Corrected Updated L-band (mostly INMARSAT) file.

[dlwtrunked]

I have discovered that some of my older rather than most recent files were merged in the L-band (mostly INMARSAT) satellite frequency list that I posted last month. Additionally some new information is now available. The new list is attached and significantly better than the list from last month. If you saved the list from last month, please replace it with this one.

 

[PACNWDude]

Thank you for sharing, and updating.

 

[dlwtrunked]

I feel really bad that I had accidentally merged some older files rather than my newest ones when I made the June list. I made an extra effort to double check against that several times this time. Note that INMARSAT IsatM2M/D+ is to reach end-of-life at the end of this year and be terminated. I hand decode the bulletin board of those (it takes me a day as it is a hands on process) and think I am the only one doing that. INMARSAT IsatM2M/D+ stayed for a while on 15W after other services left but is now gone. Below is a recent sample of the INMARSAT IsatM2M/D+ bulletin board from 98 W on 1537.995 MHz. Keep in mind that this mode is a machine-to-machine mode so only numeric data was transmitted that I have re-formatted (which RadioReference will likely corrupt by deleting multiple spaces in the table) for human reading. "PSN" indicates "Paging Subset Number".

CES (LES) 604
2020 July 4 3:05
Reg. BB Reg. 3 (IOR) 64.5 E 1537.9950 MHz 4 t/s
Reg. BB Reg. 4 (POR) 177.0 E 1537.8700 MHz 4 t/s
Reg. BB Reg. 1 (AORW) 306.0 E (54.0 W) 1538.3800 MHz 4 t/s
Reg. BB Reg. 6 (AMER) 262.5 E (97.5 W) 1537.9950 MHz 4 t/s
Svc. ID 2 Global Beam PSN 0 to 15 1537.8475 MHz 16 t/s
Svc. ID 22 Global Beam PSN 0 to 15 1537.8475 MHz 16 t/s
Svc. ID 12 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 12 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s
Svc. ID 21 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 21 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s
Svc. ID 4 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 4 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s
Svc. ID 3 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 3 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s
Svc. ID 5 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 5 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s
Svc. ID 7 Global Beam PSN 0 to 7 1537.9450 MHz 16 t/s
Svc. ID 7 Global Beam PSN 8 to 15 1537.8800 MHz 16 t/s

 

[dlwtrunked]

Thank you for sharing, and updating.

Since it looks like you are in the NW US area, if you can receive it, I could decode recording of the Pacific INMARSAT IsatM2M/D+ Bulletin Board on 1537.87 as I would like to sometime do that before it goes away at the end of the year. However, that can be as long as a couple minutes (from two tone idle to two tone idle). the hands on method I use takes about a day using an audio player, screen captures, image processing, measuring the location of pixels (tones), converting tone numbers to bits in Excel, then partitioning the bits which took me free time over 2 years to figure out.
(Also, seeing a recent copy of decoded INMARSAT C bulletin board from the Pacific would be nice if someone has decoded it.)

 

[keyhole]

@dlwtrunked
which program you are using for decoding D+?

 

[dlwtrunked]

@dlwtrunked
which program you are using for decoding D+?

It took me two years to figure out how to decode it with no information--so it is a combination of tools rather than a program. Steps are roughly this: 1. Record and save an upper sideband sound file using Audacity. 2. Play it back using Argo to see the tones with a screen capture (auto screen capture) every 7 seconds. 3. Look at each of the screen captures in an image processing program (I use PaintShop Pro) to get pixel position of each tone. 4. Use the pixel positions to figure out the tone number. But one can skip the first 12 tone after the idle, then keep the next 15, then ignore the next 7 and continue keep 15/ignore 17 until the end (when the idle starts again0. Lowest frequency tone is 0 and highest is tone 31. 5. Convert each tone number to 5-bit binary 4 (add leading 0's where needed). 6. Partition the bits the right way (learned from two years of playing with it). 7. Put it in a people readable format. If I had a recording of the bulletin board from IOR on 1537.995, I would much like to decode it. Below shows part of step 6 above:
101011001101001101000001100111011011101111001011101111100101
0110000100 CES 604 (or LES 604)
0010100 2020 (year 20+2000))
0111 7 (month)
00100 4 (day)
00011 3 (hour)
000101 05 (minutes)
01100000101000000000000000000000000000 (not sure what this is but not important as never changes)
10000000 regional bulletin board (identifies what is coming next)
10011 Region 3 (IOR) (011=3)
00101011 64.5 E (43*1.5=64.5 this was the hardest thing to realize they use 1.5 degree steps for some reason_
010101110111110 1537.9950 MHz
10000000 regional bulletin board
10100 Region 4 (POR)
01110110 177 E
010101110001100 1537.8700 MHz
00 4 tones/s (applies to the two frequencies above: 0=4 tones/s, only BB now, and 1=16 tones/s)
0 (filler) etc.