Strongest Signal Ever During An Aurora

[+Iowa Tom]

I was quite surprised to see how strong all the GPS satellite signals were during the height of the aurora, an example of which is shown below, on November 17, 2004. Can anybody tell me what was going on to allow such a strong signal to get through? The GPSr shows my Magellan that I holding up just after midnight during one of the peaks of activity in the northern lights. [Notice I have clear tape across the screen to protect it. I wish I would have done that with my digital camera!]

 

 

 

Thanks,

 

-it

[+Isonzo Karst]

Dont know squat about it - but I'm jealous of seeing the aurora, I haven't seen one since a childhood camping trip to Canada. Thanks for posting the picture.

[+Wandering Bears]

I've not seen one either. We've lived in WV for three years, and supposedly you can see them from here sometimes.

 

I just posted to congratulate you on your excellent choice in GPS.

 

[+StarBrand]

Can't explain it either but nice picture!! If anything a geomagnetic storm should interfere with radio signals.

 

And for a head's up on possible Aurora's - Check out www.spaceweather.com

[+Team Neos]

Your post was very thought provoking~ and the photo was magnificent!

 

Naturally, my first thought was an electromagnetic storm should cause a decrease in the signal strength from satellites--and then I remembered that the ionosphere changes throughout the day and night anyway with temperature and solar energy (light) change. It makes sense that an electromagnetic storm, or any other significant change in energy from the solar wind, would effect the density of the ionosphere. So I poked around a bit and found several references to increased GPS signal strength during those kinds of events. (Listed below).

 

Now my question: Would the apparent maximum signals also mean increased accuracy--or did they only appear to be stronger because they were regularly occuring (dispersed)--In other words, would accuracy increase or actually decrease during the same time period?

 

http://www.ngs.noaa.gov/CORS-Proxy/ionosphere/TEC.jsp

 

http://www.koeri.boun.edu.tr/astronomy/primer.html

about half-way down

 

http://iono.jpl.nasa.gov//press.html

enhanced signals

 

http://en.wikipedia.org/wiki/Geomagnetic_storm

wikipedia-"The solar wind pressure on the magnetosphere will increase or decrease depending on the Sun's activity. These solar wind pressure changes modify the electric currents in the ionosphere."

[+Iowa Tom]

StarBrand said, "And for a head's up on possible Aurora's - Check out www.spaceweather.com."

 

Speaking of spaceweather.com, they just released an Aurora Mega-Gallery at: http://www.spaceweather.com/aurora/gallery.html It is awesome to say the least! A friend of mine, Stan Richards, has some pictures there. Stan started an e-mail aurora alert a couple years ago and I was the first to sign up. It's primarily for areas in the 40 - 43 degrees north latitudes. Spaceweather has a cell phone alert service which I will be signing up for in about 4- 5 years or so, when we near another peak in the sunspot cycle. The aurora that I posted a picture of was awe-inspiring. I was even watching it in my side door rear view mirror on the way home! Almost hated to go to bed that night. They are usually at their best around local midnight. If anyone wants me to send them some real time aurora update URLs, one of which is to a site where people all over the world talk about what they are seeing right then, e-mail me privately. One of the mysterious effects that shows up in some aurora pictures is a series of Newton's rings right in the middle of the picture. I just noticed that I got one of those in one of my shots! There is much debate about what causes it. Problem is, my tripod is literally worn out from use and that image is blurred.

 

Now the websites that Team Neos brought to my attention included the following:

 

http://www.koeri.boun.edu.tr/astronomy/primer.html

Systems such as LORAN and OMEGA are adversely affected when solar activity disrupts their radio wavelengths. The OMEGA system consists of eight transmitters located through out the world. Airplanes and ships use the very low frequency signals from these transmitters to determine their positions. During solar events and geomagnetic storms, the system can give navigators information that is inaccurate by as much as several miles. If navigators are alerted that a proton event or geomagnetic storm is in progress, they can switch to a backup system. GPS signals are affected when solar activity causes sudden variations in the density of the ionosphere.

 

http://iono.jpl.nasa.gov//press.html

The irregularly structured ionosphere can cause random fluctuations in both amplitude and phase of trans-ionospheric radio signals received at an antenna. The phenomenon is known as ionospheric scintillation, which degrades the quality of satellite-based navigation systems, such as GPS, and disrupts short-wave radio communications. Using the techniques developed at JPL, global ionospheric irregularities can be monitored through the global GPS network by measuring phase fluctuations in the GPS signals. The snapshot of the irregularities shown above is produced using GPS data collected from 70+ globally distributed stations during the April 10-11 geomagnetic storm. These irregularities were enhanced (higher ROTI values) at high latitudes and expanded to middle latitudes in the North American region, where disruptions in short-wave radio communications were also reported during the storm.

 

This information seems to suggest that accuracy, at least, would be degraded.

 

Interesting.

 

-it