Archive - Dec 2015 - Forum topic
Data from Port side and South was better received than from overhead or closer
Two passes of London one at 12.45.30 at 135 miles from surface receiver and the other at 14.21 and at 535 miles from surface receiver found the window for data receipt on the first was from 12.45.40 to 12.46.37 say one minute. The second was from 14.19 to 14.23. This demonstrated that the closeness to the receiving station does not always have longer communications window period. It also confirmed that receipt from the South and from the Port (Left) side of the ISS was better than from overhead.
73s for 2016
M0TCE London UK
Two passess afternoon 31st December 2015 further away and longer data reception at 145.825Mz FM
Two passes of London one at 12.45.30 at 135 miles from surface receiver and the other at 14.21 and at 535 miles from surface receiver found the window for data receipt on the first was from 12.45.40 to 12.46.37 say one minute. The second was from 14.19 to 14.23. This demonstrated that the closeness to the receiving station does not always have longer communications window period. It also confirmed that receipt from the South and from the Port (Left) side of the ISS was better than from overhead.
73s for 2016
M0TCE London UK
Two passess afternoon 31st December 2015 further away and longer data reception at 145.825Mz FM
Two passes of London one at 12.45.30 at 135 miles from surface receiver and the other at 14.21 and at 535 miles from surface receiver found the window for data receipt on the first was from 12.45.40 to 12.46.37 say one minute. The second was from 14.19 to 14.23. This demonstrated that the closeness to the receiving station does not always have longer communications window period. It also confirmed that receipt from the South and from the Port (Left) side of the ISS was better than from overhead.
73s for 2016
M0TCE London UK
31st Dec 2015 Sporadic E from ISS 11.03.50 before pass by London
On the 31st December 2015 listening from 11.03.30 am before ISS was due to pass London at 11.09.03 am Sporadic E data received at 11.03.50, 11.04.14 and 11.04.40 and then at 11.07.46. Data from ISS receieved from 11.08.44 to 11.11.00 am. Noise bursts from 11.11.30 to 11.15.10am. Noise was heard on approach to London on 11.06.12 to 11.07.40. Also from 11.07.50 to 11.08.25 am with gap to 11.08.44 when data stream by normal VHF received. The pass by London on a clear sky day did not permit the ISS to be seen in the sky.
31st Dec 2015 Sporadic E from ISS 11.03.50 before pass by London
On the 31st December 2015 listening from 11.03.30 am before ISS was due to pass London at 11.09.03 am Sporadic E data received at 11.03.50, 11.04.14 and 11.04.40 and then at 11.07.46. Data from ISS receieved from 11.08.44 to 11.11.00 am. Noise bursts from 11.11.30 to 11.15.10am. Noise was heard on approach to London on 11.06.12 to 11.07.40. Also from 11.07.50 to 11.08.25 am with gap to 11.08.44 when data stream by normal VHF received. The pass by London on a clear sky day did not permit the ISS to be seen in the sky.
Good data period but shorter distance on surface than better pass of 30th December 2015 at 145.825Mz FM
From 9.25am to 9.29.45 only bursts of noise. During ISS London pass:
31 Dec 09:29:33 10° SW 09:32:43 50°SSE 09:35:54 10° E
31st December 2015 9.30 am by London on 145.825 for 560 surface miles
From 9.25am to 9.29.45 only bursts of noise. During ISS London pass:
31 Dec 09:29:33 10° SW 09:32:43 50°SSE 09:35:54 10° E
December 30th
Summary of 4 passes on 30th December 2015 excluded one pass
On the 30th December the ISS data packet transmissions was listened for from 15.11 to 15.19 at 780 Miles from London. The 10 degrees above horizon window was three minutes from 15.13 to 15.15.30. Listening was on 145.825. The period 15.11 to 15.13.40 was noise only at the time of data packets. There was some data discrimination from 15.13.40 through least distance perpendicular to the pass at 15.14. Some reception was determined to 15.16. After 15.16 to 15.19 mainly squelch noise and no data discernable.
Distant pass 780 Miles NW to SE over Spain reduced data window
On the 30th December the ISS data packet transmissions was listened for from 15.11 to 15.19 at 780 Miles from London. The 10 degrees above horizon window was three minutes from 15.13 to 15.15.30. Listening was on 145.825. The period 15.11 to 15.13.40 was noise only at the time of data packets. There was some data discrimination from 15.13.40 through least distance perpendicular to the pass at 15.14. Some reception was determined to 15.16. After 15.16 to 15.19 mainly squelch noise and no data discernable.
Quality of data packets change from pass to pass due to antenna positions and distances 30th Dec 2015
The pass to from the NW to SE was weaker and more noisy for shorter period of 13.37 to 13.40 hours on 145.825 possibly due to position shading of vertical ground antenna compared to earlier clear pass in morning. Again the approaching ISS had poorer signal than departing ISS.
73's for 2016
M0TCE