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FRC 9 Nov 2010 - K9LA Propagation Topics Carl Luetzelschwab K9LA

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Presentation on theme: "FRC 9 Nov 2010 - K9LA Propagation Topics Carl Luetzelschwab K9LA"— Presentation transcript:

1 FRC 9 Nov 2010 - K9LA Propagation Topics Carl Luetzelschwab K9LA k9la@arrl.nethttp://mysite.ncnetwork.net/k9la

2 FRC 9 Nov 2010 - K9LA A Little About K9LA Novice license WN9AVT in October 1961 Novice license WN9AVT in October 1961 Selected K9LA in the mid 1970s Selected K9LA in the mid 1970s Interested in propagation, antennas, DXing, and contesting Interested in propagation, antennas, DXing, and contesting NCJ Editor from 2002-2007 NCJ Editor from 2002-2007 My wife is Vicky AE9YL – it helps that she kind of understands this ham radio thing My wife is Vicky AE9YL – it helps that she kind of understands this ham radio thing BSEE 1969 and MSEE 1972 from Purdue BSEE 1969 and MSEE 1972 from Purdue RF design engineer by profession RF design engineer by profession

3 FRC 9 Nov 2010 - K9LA What We’ll Cover Solar Minimum and Cycle 24 Solar Minimum and Cycle 24 Recent Science News Recent Science News F2 Region Variability F2 Region Variability Propagation Predictions Propagation Predictions 160m Fundamentals 160m Fundamentals 10m Opening to EU on October 11 10m Opening to EU on October 11 Old QSL Quiz Old QSL Quiz

4 FRC 9 Nov 2010 - K9LA Solar Minimum and Cycle 24

5 FRC 9 Nov 2010 - K9LA Our Recent Solar Min Pretty unusual, right?

6 FRC 9 Nov 2010 - K9LA A Look At All Recorded History Recent solar min certainly unusual in our lifetime, but not that unusual over all recorded history Note the cyclic nature

7 FRC 9 Nov 2010 - K9LA Cycle 24 Progress Solar min in December 2008 Solar min in December 2008 Smoothed sunspot number and smoothed solar flux steadily rising ever since (in spite of the ups-and-downs of the monthly mean values) Smoothed sunspot number and smoothed solar flux steadily rising ever since (in spite of the ups-and-downs of the monthly mean values)

8 FRC 9 Nov 2010 - K9LA Latest NOAA Prediction Max smoothed sunspot number of 90 and max smoothed solar flux of 140 in early 2013 Kind of looks like the actual results are a bit behind the predictions

9 FRC 9 Nov 2010 - K9LA More Predictions Over 55 predictions in the scientific literature Range from a smoothed sunspot number of 40 to 185 Somebody is going to get it right!

10 FRC 9 Nov 2010 - K9LA When Will 15m and 10m Be Back? Let’s assume the NOAA prediction is correct Let’s assume the NOAA prediction is correct 15m needs a smoothed sunspot number of about 25 (smoothed solar flux of 85) for consistent F2 propagation 15m needs a smoothed sunspot number of about 25 (smoothed solar flux of 85) for consistent F2 propagation –We’re probably there now –CQ WW PH was consistently good –CQ WW CW should be, too 10m needs a smoothed sunspot number of about 50 (smoothed solar flux of 100) for consistent F2 propagation 10m needs a smoothed sunspot number of about 50 (smoothed solar flux of 100) for consistent F2 propagation –I hope we get there in early 2011 –ARRL DX contests in February and March 2011 have the potential of being good (more than just Carib and S Amer)

11 FRC 9 Nov 2010 - K9LA Our Very Own Prediction Long solar min points to a smaller cycle out of phase with solar min duration “cycles” – Schwabe 11 yrs Hale 22 yrs Gleissberg 88 yrs De Vries 205 yrs Halstatt 2300 yrs (from Be 10 and/or C 14 )

12 FRC 9 Nov 2010 - K9LA A Recent Prediction Annales Geophysicae, 28, 1463–1466, 2010 www.ann-geophys.net/28/1463/2010/ doi:10.5194/angeo-28-1463-2010 Size of the coming solar cycle 24 based on Ohl’s Precursor Method, final estimate R. P. Kane Instituto Nacional de Pesquisas Espacias, INPE C.P. 515, 12201-970 Sao Jose dos Campos, SP, Brazil Maximum smoothed sunspot number of 58 +/- 25 Maximum smoothed sunspot number of 58 +/- 25 That’s lower than the NOAA prediction That’s lower than the NOAA prediction 10m will suffer 10m will suffer

13 FRC 9 Nov 2010 - K9LA Recent Science News

14 FRC 9 Nov 2010 - K9LA #1 - No More Sunspots? Measured the magnetic fields of sunspots for the past 17 years, and data indicates sunspot magnetism is on the decline Measured the magnetic fields of sunspots for the past 17 years, and data indicates sunspot magnetism is on the decline Sunspots seem to form only if the magnetic field is stronger than about 1500 gauss Sunspots seem to form only if the magnetic field is stronger than about 1500 gauss Solar magnetic fields may become too weak to form sunspots after 2016 or so Solar magnetic fields may become too weak to form sunspots after 2016 or so The technique looks at a spectral line emitted by iron atoms in the Sun's atmosphere The technique looks at a spectral line emitted by iron atoms in the Sun's atmosphere Livingston and Penn, EOS, July 2009

15 FRC 9 Nov 2010 - K9LA #2 - Collapsing Atmosphere

16 FRC 9 Nov 2010 - K9LA Data Pt Arguello ionosonde shows downward trends for both foF2 and hmF2 Other ionosondes show a mixed bag of results The conclusion: More analysis is needed Details: November 2010 WorldRadio Online column

17 FRC 9 Nov 2010 - K9LA #3 - Storm Warnings

18 FRC 9 Nov 2010 - K9LA #4 - Lower Ionosphere Space is just a little bit closer, BBC News, 21Dec08, news.bbc.co.uk/2/hi/science/ nature/7794834.stm Space is just a little bit closer, BBC News, 21Dec08, news.bbc.co.uk/2/hi/science/ nature/7794834.stm NASA: Ionosphere not where it should be, UPI, 17Dec08, www.tinyurl.com/3p2pcs NASA: Ionosphere not where it should be, UPI, 17Dec08, www.tinyurl.com/3p2pcs These press releases are somewhat misleading These press releases are somewhat misleading What’s not real clear is the data is for equatorial latitudes What’s not real clear is the data is for equatorial latitudes Not understanding this leads to the erroneous conclusion that the worldwide ionosphere is lower - ionosonde data shows no such trend Not understanding this leads to the erroneous conclusion that the worldwide ionosphere is lower - ionosonde data shows no such trend Details: “Is the Ionosphere Really Lower?” at mysite.ncnetwork.net/k9la under Timely Topics link Details: “Is the Ionosphere Really Lower?” at mysite.ncnetwork.net/k9la under Timely Topics link

19 FRC 9 Nov 2010 - K9LA F2 Region Variability

20 FRC 9 Nov 2010 - K9LA A Look at Ionosonde Data MUF varied from a low of just under 10 MHz to a high of just above 20 MHz This is due to the daily variation of solar radiation, right?

21 FRC 9 Nov 2010 - K9LA Not Quite August 2009 August 2009 –Zero sunspots –Constant solar flux Solar radiation creates ionization Solar radiation creates ionization But two other issues contribute to the final ionization But two other issues contribute to the final ionization –Magnetic field activity –Events in the lower atmosphere coupling up to the ionosphere Thankfully the E region is more predictable – it’s under direct solar control Thankfully the E region is more predictable – it’s under direct solar control –Solar activity –Solar zenith angle August 2009

22 FRC 9 Nov 2010 - K9LA Another Subtle Effect The worldwide ionosphere is not necessarily “in step”

23 FRC 9 Nov 2010 - K9LA Propagation Predictions

24 FRC 9 Nov 2010 - K9LA How Do You Model the Ionosphere? It should be obvious that plugging in today’s sunspot number or today’s 10.7 cm solar flux does not tell us what the F2 region of the ionosphere is doing today It should be obvious that plugging in today’s sunspot number or today’s 10.7 cm solar flux does not tell us what the F2 region of the ionosphere is doing today The developers of the model of the ionosphere for propagation prediction recognized this The developers of the model of the ionosphere for propagation prediction recognized this They were forced to implement a statistical model They were forced to implement a statistical model Thus our propagation predictions are statistical over a month’s time frame Thus our propagation predictions are statistical over a month’s time frame The correlation between what the Sun is doing and what the ionosphere is doing is based on a smoothed solar index and monthly median ionospheric parameters The correlation between what the Sun is doing and what the ionosphere is doing is based on a smoothed solar index and monthly median ionospheric parameters

25 FRC 9 Nov 2010 - K9LA Review of Correlations Bottom line: We do not have daily predictions Median is predicted – use with variability tables to determine other probabilities MUF could be anywhere from 17 MHz to 28 MHz at a solar flux of 170

26 FRC 9 Nov 2010 - K9LA So What Does All This Mean? Let’s do a prediction for CQ WW CW Let’s do a prediction for CQ WW CW We’ll do it for 15m from Philly to Europe (DL) We’ll do it for 15m from Philly to Europe (DL) We’ll use VOACAP We’ll use VOACAP –1 KW –13 dBi Yagis I used a smoothed sunspot number of 36 (from http://www.swpc.noaa.gov/ftpdir/weekly/Predict.txt) I used a smoothed sunspot number of 36 (from http://www.swpc.noaa.gov/ftpdir/weekly/Predict.txt) http://www.swpc.noaa.gov/ftpdir/weekly/Predict.txt http://www.swpc.noaa.gov/ftpdir/weekly/Predict.txt

27 FRC 9 Nov 2010 - K9LA Results MUF On half the days of the month at 1400 UTC, the MUF will be at least 25.6 MHz On half the days of the month at 1400 UTC, the MUF will be at least 25.6 MHz On 89% of the days of the month at 1400 UTC, the MUF will be at least 21.0 MHz On 89% of the days of the month at 1400 UTC, the MUF will be at least 21.0 MHz On 27% of the days of the month at 1400 UTC, the MUF will be at least 28.0 MHz On 27% of the days of the month at 1400 UTC, the MUF will be at least 28.0 MHz UTC Median MUF 15m10m Signal Strength The median signal strength on 15m at 1400 UTC is -103 dBW (-73 dBm = S9) The median signal strength on 15m at 1400 UTC is -103 dBW (-73 dBm = S9) The median signal strength on 10m at 1400 UTC is -142 dBW (-112 dBm = S1) The median signal strength on 10m at 1400 UTC is -142 dBW (-112 dBm = S1) Unfortunately we don’t know which days will be the good ones Rule of thumb – MUF can vary about the median by one band and signal strength can vary about the median by a couple S-units on any given day in the one-month period

28 FRC 9 Nov 2010 - K9LA 160m Fundamentals

29 FRC 9 Nov 2010 - K9LA Interesting Question Is propagation on 160m different than propagation on, say, 10m? Most would answer “Yes”

30 FRC 9 Nov 2010 - K9LA “No” Is Also A Good Answer An electromagnetic wave on 1.8 MHz follows the same laws of physics as an electromagnetic wave on 28 MHz What “laws of physics” should we look at? The three that tell us – –Refraction (inversely proportional to the square of the frequency) – –Absorption (inversely proportional to the square of the frequency) – –Polarization (Earth’s magnetic field plays critical role)

31 FRC 9 Nov 2010 - K9LA Ray Trace on 10m O-wave and X-wave pretty much follow the same path O-wave and X-wave pretty much follow the same path –Index of refraction approximately the same –X-wave bends a bit more –Apogee approx 240 km –Hops to 4000 km O-wave and X-wave pretty much incur the same amount of absorption O-wave and X-wave pretty much incur the same amount of absorption –Approx 2 dB per hop O-wave and X-wave are circularly polarized O-wave and X-wave are circularly polarized On 10m the O-wave and X-wave propagate approximately equally

32 FRC 9 Nov 2010 - K9LA Ray Trace on 160m O-wave and X-wave do not follow the same path O-wave and X-wave do not follow the same path –Index of refraction significantly different –X-wave bends more –Apogee approx 170 km for O-wave –Hops limited to < 3000 km O-wave and X-wave do not incur the same amount of loss O-wave and X-wave do not incur the same amount of loss –Absorption significantly different –X-wave usually considered to be out of the picture when operating frequency is near the electron gyro- frequency ranges from.7 to 1.7 MHz worldwide ranges from.7 to 1.7 MHz worldwide –Approx 17 dB per hop Polarization of O-wave tends towards elliptical (vertical) at mid to high latitudes Polarization of O-wave tends towards elliptical (vertical) at mid to high latitudes 160m - shorter hops 160m - more lossy hops 160m – only one characteristic wave propagates

33 FRC 9 Nov 2010 - K9LA Multi-hop on 160m Based on previous slides, multi-hop propagation on 160m is via hops that are short and lossy Based on previous slides, multi-hop propagation on 160m is via hops that are short and lossy –“Short” is relative – but it’s not 4000 km hops like on 10m Per our present understanding of the lower ionosphere, at night a 1500 Watt signal with quarter-wave verticals on both ends can go about 10,000 km before being below the noise level of our receiving system (usually limited by external noise) Per our present understanding of the lower ionosphere, at night a 1500 Watt signal with quarter-wave verticals on both ends can go about 10,000 km before being below the noise level of our receiving system (usually limited by external noise) –Daytime limit around 1000 km

34 FRC 9 Nov 2010 - K9LA This Suggests Another Mode Distances greater than 10,000 km are likely due to ducting in the electron density valley above the nighttime E region peak Ducting incurs less loss due to less transits through the absorbing region and less ground reflections Key issues: what controls entry into the duct, what controls staying in the duct, what controls exiting the duct?

35 FRC 9 Nov 2010 - K9LA NM7M’s Work with GCRs Galactic cosmic rays are mostly very high energy protons coming in from all directions – day and night Galactic cosmic rays are mostly very high energy protons coming in from all directions – day and night Quiet magnetic field (solar min) lets more in – more ionization in the lower ionosphere Quiet magnetic field (solar min) lets more in – more ionization in the lower ionosphere Active magnetic field (solar max) keeps them out – less ionization Active magnetic field (solar max) keeps them out – less ionization GCR measurement on Earth (and thus impact to ionosphere) is out of phase with solar cycle GCR measurement on Earth (and thus impact to ionosphere) is out of phase with solar cycle galactic cosmic rays

36 FRC 9 Nov 2010 - K9LA CGRs and the Valley NM7M’s theory is that galactic cosmic rays play an important role in the valley formation, and thus ducting NM7M’s theory is that galactic cosmic rays play an important role in the valley formation, and thus ducting At solar maximum, not many GCRs ionizing the valley – nice and deep At solar maximum, not many GCRs ionizing the valley – nice and deep –Extremely long distance DXing best at solar max –NM7M has some interesting plots of QSO distance vs GCR decrease, but there is conflicting data At solar minimum, too many GCRs ionizing valley – fills up more and all we have left is lossy multi-hop At solar minimum, too many GCRs ionizing valley – fills up more and all we have left is lossy multi-hop solar min -------- solar max -------

37 FRC 9 Nov 2010 - K9LA W4DR Observations personal e-mail, late December 2009 “I have been DXing on 160 since 1970, with for the most part above-average antennas. “I have been DXing on 160 since 1970, with for the most part above-average antennas. During this present sun spot minimum (the last 2 years and especially the last 8 weeks) I have worked more polar path stations, Zones 17, 18, 19 and 23 plus some 40's than I have in the previous 37 years. This included my first ever zone 23 on Dec 12. During this present sun spot minimum (the last 2 years and especially the last 8 weeks) I have worked more polar path stations, Zones 17, 18, 19 and 23 plus some 40's than I have in the previous 37 years. This included my first ever zone 23 on Dec 12. On the other hand I have not worked any long path or bent path SE Asians in the last 4- 5 years.” On the other hand I have not worked any long path or bent path SE Asians in the last 4- 5 years.” Suggests that 160m propagation over the poles is best at solar min, and long distance DXing may need a bit more geomagnetic field activity to keep GCRs out N4IS and K1ZM recently reported long-haul DX into SE Asia

38 FRC 9 Nov 2010 - K9LA 10m Opening to EU on Oct 11

39 FRC 9 Nov 2010 - K9LA The Path East Coast reported good 10m opening to EU on Oct 11 East Coast reported good 10m opening to EU on Oct 11 PJ2T also reported this PJ2T also reported this No data from Goose Bay No data from Goose Bay –So we don’t know what was happening on the East Coast end El Arensillo (Spain) gives a good picture on the Europe end El Arensillo (Spain) gives a good picture on the Europe end

40 FRC 9 Nov 2010 - K9LA Ionosonde Data Something happened on or before the 11th

41 FRC 9 Nov 2010 - K9LA Space Weather It is likely that the gradual increase followed by a gradual decrease in the K index played a role in this 10m opening It is likely that the gradual increase followed by a gradual decrease in the K index played a role in this 10m opening Ionization targets at F2 region altitudes (oxygen atoms) can be re-distributed in the atmosphere due to an elevated K index Ionization targets at F2 region altitudes (oxygen atoms) can be re-distributed in the atmosphere due to an elevated K index

42 FRC 9 Nov 2010 - K9LA Old QSLs or What Deleted Entity Is It?

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51 Summary Cycle 24 is likely to be a small one Cycle 24 is likely to be a small one –Along with the next couple of cycles  Carefully read and evaluate science news Carefully read and evaluate science news We don’t have daily predictions We don’t have daily predictions 160m is still a tough band to understand 160m is still a tough band to understand –For more on propagation on 160m, visit http://mysite.ncnetwork.net/k9la, and click on the 160m link on the left http://mysite.ncnetwork.net/k9la Keep an eye on 10m Keep an eye on 10m

52 FRC 9 Nov 2010 - K9LA Q & A


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