Friday, January 29, 2010
Johannes Kepler explained the phenomenon 400 years ago. The Moon's orbit around Earth is not a circle but an ellipse, with one side 50,000 km closer to Earth than the other. Astronomers call the point of closest approach "perigee," and that is where the Moon will be Friday night through Saturday morning.
A good time to look is around sunset when the Moon is near the eastern horizon. At that time, illusion mixes with reality to produce a truly stunning view. For reasons not fully understood by psychologists, low-hanging Moons look unnaturally large when they beam through foreground objects such as buildings and trees. Why not let the "Moon illusion" amplify a full Moon that's extra-big to begin with? The swollen orb rising in the east may seem close enough to touch.
HOW TO READ PROPAGATION NUMBERS
The A index [ LOW is GOOD ]
- 1 to 6 is BEST
- 7 to 9 is OK
- 11 or more is BAD
Represents the overall geomagnetic condition of the ionosphere ("Ap" if averaged from the Kp-Index) (an average of the eight 3-hour K-Indices) ('A' referring to amplitude) over a given 24 hour period, ranging (linearly) typically from 1-100 but theoretically up to 400.
A lower A-Index generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; a low & steady Ap-Index generally suggest good propagation on the 30, 40, 60, 80, & 160 Meter Bands.
SFI index [ HIGH is GOOD ]
- 70 NOT GOOD
- 80 GOOD
- 90 BETTER
- 100+ BEST
The measure of total radio emissions from the sun at 10.7cm (2800 MHz), on a scale of 60 (no sunspots) to 300, generally corresponding to the sunspot level, but being too low in energy to cause ionization, not related to the ionization level of the Ionosphere.
Higher Solar Flux generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; Solar Flux rarely affects the 30, 40, 60, 80, & 160 Meter Bands.
K index [ LOW is GOOD ]
- 0 or 1 is BEST
- 2 is OK
- 3 or more is BAD
- 5 is VERY VERY BAD
The overall geomagnetic condition of the ionosphere ("Kp" if averaged over the planet) over the past 3 hours, measured by 13 magnetometers between 46 & 63 degrees of latitude, and ranging quasi-logarithmically from 0-9. Designed to detect solar particle radiation by its magnetic effect. A higher K-index generally means worse HF conditions.
A lower K-Index generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; a low & steady Kp-Index generally suggest good propagation on the 30, 40, 60, 80, & 160 Meter Bands.
Terms of Service
I am not responsible for any thing that happens to your mental health, computer and all personal property because you visited my site.
This site is a collection of some things sent to me by e-mail, obtained from other blogs and the internet. If there is a picture or quote that is copyrighted to you let me know and I will remove your item .
Thoughts expressed in my blog are just that . I give My Opinion on the many events, products and how too, reported by the media and other web-sites.
Do not use this blog site to obtain weather events or disasters information. What I post may not be correct. Always get information from the proper media, weather (NWS)(NOAA)
Pacific Tsunami Warning Center and USGS sites