4am Propagation VK6RSX Dampier 50.304MHz beacon to Perth
Posted: Wed Jul 15, 2015 10:34 pm
VK6RSX Dampier 50.304 MHz beacon to VK6DVR Perth Propagation at 4am WAST 13-Jul-2015
I was scanning the Argo software waterfalls from the other morning and found 4-minutes of really strong signals that didn't look or sound like MS at all.
4-minutes of VK6RSX Dampier 50.304 MHz beacon - Which Propagation modes do we have in this recording at 4am WAST 13-Jul-2015?
View the YouTube screencast video I made from the .WAV file: https://youtu.be/Z6Jw5DUc1pU
The movie has been sped up about 2.5 times, so it's not too long to watch.
So, which one could it be?
1: Aircraft Enhancement (AE): Specular Reflections from the body/wings of two fly-in/fly-out large-body jets angled at ascent/descent and maybe near to each end of the flight path from Karratha/Perth between 04:15 and 04:20 am on 13-Jul-2015. Trouble with it being AE, is that there doesn't appear to be any evidence of Doppler-shift in the signals recorded.
2: Reflections from an orbital pass of the ISS at 400-km above the earth. (unsure, needs checking, never heard of it - is it possible under certain angles of the dangle?).
3: Meteor-scatter (MS - unlikely as signal presents the wrong signature, ie there was no pancake splash effect at the start).
4: Tropo-scatter (1,236km path may be a bit longish, no Hepburn Charts evidence).
On Jul 13th, there is just a surface trough running down and off the West coast. 5: Sporadic-E (does Es form this strongly at this low-mid latitude at this time of the year?).
The main consensus of opinion so far, seems to point to signals having the characteristic fading pattern of Sporadic-E.
From: Roger Harrison, VK2ZRH - "Lesson for the Day" (thanks, Roger).
Danny, It sounds distinctly like sporadic E to me, with that characteristic fading pattern.
Sporadic E is not unusual at this time of year, around the Winter solstice. Es can occur at *any* time of day or night, as the Sun does not generate the ionisation, wind shear in the E-region "sweeps up" metallic ions (chiefly iron and magnesium), compressing them into a thin, dense layer at around 95-120 km.
73, Roger VK2ZRH
6: Multi-object/Multi-path combination of various propagation modes (unlikely).
7: Two instances have now been seen at around the same time of the morning (within the hour) and requires further comparisons and analysis.
The movie has been sped up about 2.5 times, so it's not too long to watch.
Please get back to me with your thoughts on which propagation mode you see. I'm very curious.
PS: Scroll down my website and checkout the VK6RSX beacon photos and also click on the Meteor trail right up top.
VK6DVR Danny Robinson | VHF Weak-signal & Meteor-Scatter on 6-Metres | Perth, W.Australia: http://goo.gl/9fncQ1
https://sites.google.com/site/vk6dvr/
73's Danny VK6DVR
I was scanning the Argo software waterfalls from the other morning and found 4-minutes of really strong signals that didn't look or sound like MS at all.
4-minutes of VK6RSX Dampier 50.304 MHz beacon - Which Propagation modes do we have in this recording at 4am WAST 13-Jul-2015?
View the YouTube screencast video I made from the .WAV file: https://youtu.be/Z6Jw5DUc1pU
The movie has been sped up about 2.5 times, so it's not too long to watch.
So, which one could it be?
1: Aircraft Enhancement (AE): Specular Reflections from the body/wings of two fly-in/fly-out large-body jets angled at ascent/descent and maybe near to each end of the flight path from Karratha/Perth between 04:15 and 04:20 am on 13-Jul-2015. Trouble with it being AE, is that there doesn't appear to be any evidence of Doppler-shift in the signals recorded.
2: Reflections from an orbital pass of the ISS at 400-km above the earth. (unsure, needs checking, never heard of it - is it possible under certain angles of the dangle?).
3: Meteor-scatter (MS - unlikely as signal presents the wrong signature, ie there was no pancake splash effect at the start).
4: Tropo-scatter (1,236km path may be a bit longish, no Hepburn Charts evidence).
On Jul 13th, there is just a surface trough running down and off the West coast. 5: Sporadic-E (does Es form this strongly at this low-mid latitude at this time of the year?).
The main consensus of opinion so far, seems to point to signals having the characteristic fading pattern of Sporadic-E.
From: Roger Harrison, VK2ZRH - "Lesson for the Day" (thanks, Roger).
Danny, It sounds distinctly like sporadic E to me, with that characteristic fading pattern.
Sporadic E is not unusual at this time of year, around the Winter solstice. Es can occur at *any* time of day or night, as the Sun does not generate the ionisation, wind shear in the E-region "sweeps up" metallic ions (chiefly iron and magnesium), compressing them into a thin, dense layer at around 95-120 km.
73, Roger VK2ZRH
6: Multi-object/Multi-path combination of various propagation modes (unlikely).
7: Two instances have now been seen at around the same time of the morning (within the hour) and requires further comparisons and analysis.
The movie has been sped up about 2.5 times, so it's not too long to watch.
Please get back to me with your thoughts on which propagation mode you see. I'm very curious.
PS: Scroll down my website and checkout the VK6RSX beacon photos and also click on the Meteor trail right up top.
VK6DVR Danny Robinson | VHF Weak-signal & Meteor-Scatter on 6-Metres | Perth, W.Australia: http://goo.gl/9fncQ1
https://sites.google.com/site/vk6dvr/
73's Danny VK6DVR