Meteor Scatter via 17m and 20m QRSS

This is a summary of  Meteor Scatter test being conducted on 20m by WD4AH, WD4ELG and myself.   G0FTD and company in England have pioneered the use of QRSS on 10m to observe meteor pings and do so on a regular basis.  We have been pushing to explore the bands below 10m to see if meteor scatter can be detected there.  I have observed many pings from a sw brodcast station 220 miles/357 km to the north of me on 12050 kHz so know it's feasible at high power levels but how about at the low powers used by the QRSS community?  As a starting point we have concentrated on 20 and 17m.  WD4AH is 276 miles/444 km ESE of me while WD4ELG is 584 miles/ 935 km NE of me.  The strength of meteor pings decreases as the 4th power of the distance so for identical equipment ELG's signal should be about 20 times weaker than that of AH.

Our first test was on August 13 during the Perseid shower, a second on September 29 during the Sextantid Daytime shower and a third on October 23 during the Orionids shower.

Perseids  -  This was indeed a learning experience for us all.  We attempted to use 2 bands with AH and ELG transmitting on 20m to my  grabber and with me transmitting on 17m to their grabbers.  Here's a spreadsheet of the plan:

Station                 MEPT                                  Grabber                      QRSS Mode

W4HBK         TS-480 @ 5W on 17m         TS-440 on 20m                  CW

WD4AH         U3S @ 1/2W on 20m           SDR on 17m                    DFCW

WD4ELG      U3S @ 1/2W on 20m            SDR on 17m                    FSKCW

AH and ELG immediately ran into a problem of overload of their SDR receivers from their simeltaneious transmission on 20m.  The attempt on 17m was abandoned.

On 20m I  could see two components to their signals one which appeared to be meteor pings and another which appeared to be a contribution from the ionosphere or troposphere.  The skip was unexpected as it occurred between midnight and Sunrise when the band was normally dead as a doornail.  However it was during the Es season so that is a possibility.  We interpreted the results as a weak background of skip punctuated by meteor pings.

As to meteor pings only one possibility was seen on ELG, Figure 1,   while many were seen on AH, Figure 2.

Figure 1.  WD4ELG Meteor Pings

Figure 2a.  WD4AH pings

Figure 2b.  WD4AH pings

Figure 2c.  WD4AH pings

A problem I found in looking for pings was the nature of the message used.   We chose "regular" QRSS messages.   ELG used fsk cw and AH, dfcw, both with a shift of 5 Hz.  The short time span of a ping along with it's Doppler shift made a confusion of the observed data.  Lesson learned: the best signal for ms work is a continuous, unshifted signal but that wouldn't be QRSS, would it.  Likewise  propagation condx which interfere with pings should be avoided if possible.

Sextantids  -   This is a daytime shower about which little is know since most ms observations are oriented towards visual sightings.  We chose a message with only a 1 Hz shift since this is almost a straight line but still a legal  and readable QRSS signal.  The plan was to have WD4ELG and WD4AH transmit on 20m with W4HBK doing the grabbing.  Equipment failure forced ELG off the air but we pressed on with AH's signal.  As if that weren't enough a major RTTY contest started up which forced AH to QSY to the low end of the band at around 14001.84 kHz.  Following this adjustment we recorded numerous pings plus what appeared to be weak skip or tropo as we had seen during the Perseids.

Figures 3a and 3b show some of the pings on individual 10 minute grabs.  Figure 4 is from my slow grabber and shows the overall signal from AH during the test.  The jump in frequency identified as "SL Hiccup" was a spontaneous change in center frequency, a quirk of Spectrum Lab.  Also at 1600z there was a very strong increase in AH for about 3 minutes.  Actually,  I recalled having seen this before on his signal on my 20 and 30m grabbers during regular QRSS activity near Sunrise.  The distance is well within my skip zone and I  rarely see  QRSS stations that are "too close" and which I know are QRV  More about this below.

Figure 3a.  WD4AH pings

Figure 3b.  WD4AH pings

Figure 4.  WD4AH on 8 hr Grabber

I also did a stack of most of the 10 minute frames between 1330z and 1530z that combines all the pings which I will call tropo effect, Figure 5.

Figure 5.  Stack of  WD4AH 10 Minute Grabs

A Google search for what might be the cause of the weak background found that coastal tropo is common in Florida  The path between Alachua and Pensacola indeed skirts the northern Gulf coast and is likely the cause of the background. Generally a vhf/uhf phenomena it decreases with frequency but is probably ignored on HF because of all the other modes of propagation available.

In summary, we believe we have definitely seen many meteor pings on 20m during the Daytime Sextantids Metero shower and possibly have stumbled on a 20m tropo effect which has been ignored or forgotten.

Lessons learned so far: (1) use as continuous a signal as possible with as little frequency shift as possible, (2) check for contests and (3) check equipment including grabbers before the test.

Orionids   For this test W4HBK transmitted a 5 Watt QRSS-CW signal on 17m while WD4AH and WD4ELG did the grabbing honors.

The results for AH were straightforward in that we saw a number of pings with no background as discussed above.  Figure 6 is a stitch of all images and shows the total pings from roughly midnight to sunrise.

Figure 6.  Stitch of WD4AH 10 Minute Grabs

WD4ELG's signal produced what I'm fairly certain are a number of pings but signal fell right between two extraneous lines that often appear on our waterfall displays, Figures 7a,b,c,d.

Figure 7a.  WD4ELG Meteor Pings

Figure 7b.  WD4ELG Meteor Pings

Figure 7c.  WD4ELG Meteor Pings

Figure 7d.  WD4ELG Meteor Pings

In addition there was also a background signal which was probably due to either tropo or ionospheric propagation though the latter would be TOTALLY unexpected for the hours between midnight and sunrise local time.  Figure 8 is a stitch of some of the 10 minute grabs  showing what we think are the meteor pings superimposed on a non-meteor effect during the first half of the image and transitioning to ionospheric skip at Sunrise.  The signal at the lower right is KJ6ANV in New Mexico.  The wavy nature of the signal is probably due to drift in my TS-480 transceiver as it heats and cools during the 10 minute frame.

Figure 8.  Stitch if WD4ELG 10 Minute Grabs

Once more we seem to see a combination of meteor pings overlaying an unexpected effect by either the tropohphere or ionosphere.  The latter could be weak Sporatic E trying to happen and then being augmented by meteors.  Tropospheric ducting can't be ruled out either since the weather pattern over the Southeastern USA has been unusual this year, warmer and wetter with a delay in the cool, clear days normally seen.  This may be conducive to temperature inversions though we did not record wx data during our test period.

We have tried to use lessons learned to improve as we went along but equipment and planning failures still were a problem.  The latter as caused by not being aware of a major RTTY contest which made intolerable QRM.

Our conclusions are that we have definitely seen meteor pings on the shorter path between W4HBK and WD4AH on both 20 and 17m  What seems to be pings on the longer path between W4HBK and WD4ELG is tantalizingly close to certain but needs further study.  As I said in the opening paragraph "The strength of meteor pings decreases as the 4th power of the distance so for identical equipment ELG's signal should be about 20 times weaker than that of AH."