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The Gyrator III VLF Receiver

The latest version of the Gyrator series of VLF receivers (first developed in the 1990s) is the Gyrator III, a revision of Arthur Stokes' Gyrator II by Guglielmo Di Filippo (observer A-93).


Circuit diagrams and wiring for the Gyrator III are available here in Microsoft Word and PDF formats: .doc, .pdf

AAVSO Sudden Ionospheric Disturbance Program Observers

Active Observers (Data submitted within the last year)

OBS ID Observer Name Station Location
A-94 Al McWilliams St Cloud, MN
A-96 Roberto Battaiola Milan, Italy
A-97 Jon Wallace Torrington, CT
A-118 Lionel Loudet Muret, France
A-120 Bob Terrill Ballarat, Victoria, Australia
A-121

SID Database

About the SID database

The Sudden Ionospheric Disturbance (SID) Database lists all events identified in the AAVSO Solar Bulletin. These results are provided monthly by the worldwide network of SID observers in the AAVSO Solar Division. Individual results are correlated with other observers' reports and reduced to a list of events with high definiteness ratings.

SID Monitoring Group FAQ

When the ultraviolet rays from the Sun hit the Earths atmosphere the energy they possess work to knock electrons off of the atoms and molecules that the atmosphere is made up of. These free electrons make up a region of the atmosphere known as the Ionosphere. The region is strongest on the daytime side of the earth since it is dependant on the energy from the solar ultra violet rays.

VLF Station List

VERY LOW FREQUENCY (VLF) RADIO STATIONS
                                     
           Station            Station     Frequency        Radiated
             Site               ID          (kHz)            Power
                                                             (kW)
  U.S. Navy                     
       Cutler, ME                NAA          24.0            1000
       Jim Creek, WA             NLK          24.8             250
       Lualualei, HI             NPM          21.4             566
       LaMoure, ND               NML          25.2             500

Solar Program, Reducing Data and Email Format

Solar Program, Reducing Data and Email Format

Reducing Data Gathered by VLF Monitoring Systems

(Extracted from SID Technical Bulletin Vol. 3, Number 4, Oct. 1992)

The Zurich Classification System of Sunspot Groups

The Zurich Classification System of Sunspot Groups

Contributed by Tom Fleming (FLET)

 

"A" Type: One or more tiny spots that do not demonstrate bi-polarity or exhibit penumbra.

sunspota.jpg
 

"B" Type: Two or more tiny spots that demonstrate bi-polarity but do not exhibit penumbra.

sunspotb.jpg

 

 

 

 

Dances with Wolfs: A Short History of Sunspot Indices

Contributed by Carl E. Feehrer (FEEC)

Revised August 2000

Accuracy and Consistency in the Production of the American Sunspot Number (Ra)

Addendum

ACCURACY AND CONSISTENCY IN THE PRODUCTION OF THE AMERICAN SUNSPOT NUMBER (Ra)

Contributed by Carl E. Feehrer (FEEC)

Guidelines for new solar observers

Guidelines for New Solar Observers

  • Do not look directly at the sun without the protection offered by a filter. For naked eye viewing, a piece of #14 welder's glass provides adequate protection. Do not use overexposed film, dark glasses, or other media that are not designed specifically for solar viewing.

Pages

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484