Page Created: 2016 January 04

Page Updated: 2017 February 09

Sudden Ionospheric Disturbance (SuperSID ) since 2016 January

Welcome to Starlight Cascade Observatory SuperSID System Page! Near Yarker, Ontario, Canada. (44.22.39 N 76.45.47 W    151M Elevation)

SuperSID is an automated, 20-40 KHz radio receiver and antenna system located near Yarker (outside of Kingston) Ontario Canada. It takes readings of solar flux signal strength once every 5 seconds, 24 hours a day. It went operational in 2016 January, replacing an older SID system. We built a new 2m wide loop antenna as well.

University Louisville SID Reference
lastline.txt * Image Archive * dataarchive

NAA-Maine 24.0KHz

NLK Washington 24.8 KHz

NML NorthDakota 25.2 KHz
Y axis = 50

NAA-Maine 24.0KHz

NLK Washington 24.8 KHz

NML NorthDakota 25.2 KHz
Y axis = 500 (as sometimes the data goes offscale)


Supersid is a newer multifrequency Sudden Ionospheric Disturbance detection system avilable from

Our data is uploaded once daily to:

  • Our data is on the page.. search for the letters "SCO"


               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
           LaMoure, ND               NML          25.2             500

  • VLF Station List
  • SID Monitoring Station VLF List
  • Stanford VLF Station List

    In the late 1940's, the U.S. Navy realized that they needed a high powered, low frequency, transmitter on the U.S. east coast which could broadcast to the North Atlantic and Arctic Oceans for communication with submarines. A radio transmitter was established in Cutler, Maine, for this purpose and it has been in operation since 1961. One fringe benefit is that this 1 million watt transmission at 24 kilohertz can be detected across the continental United States. The signal is very sensitive to the state of the Earth's ionosphere, because, at this frequency, it it is actually piped close to the surface of the Earth during the daytime. Several other VLF stations operate around the world, but Cutler provides the strongest daytime signal in this area.

    In this installation the radio signals are received by a directional loop antenna tuned to the Cutler station. The receiver amplifies and averages the signal with a time constant of about 10 seconds and its output is recorded

    Each day at 0 hours Coordinated Universal Time the images from the previous day are placed in the imagearchive, the latest complete plot is saved in the plot archive, and a new record is started.

    Each plot should show a signal which varies erratically during the night, but is smooth and steady during the day. The transition at sunrise and sunset is a very distinctive rise and fall pattern. When a flare occurs, the prompt X-ray emission from the Sun modifies the ionosphere and produces a sudden enhancement in the very low frequency 24 kilohertz radio signal from Cutler, Maine.

    Records of this type are kept by several amateur astronomers who coordinate their efforts through the American Association for Variable Star Observers.

    From Wikipedia: The D layer is the innermost layer, 60 km to 90 km above the surface of the Earth. Ionization here is due to Lyman series-alpha hydrogen radiation at a wavelength of 121.5 nanometre (nm) ionizing nitric oxide (NO). In addition, with high Solar activity hard X-rays (wavelength less than 1 nm) may ionize (N2, O2). During the night cosmic rays produce a residual amount of ionization. Recombination is high in the D layer, the net ionization effect is low, but loss of wave energy is great due to frequent collisions of the electrons (about ten collisions every msec). As a result high-frequency (HF) radio waves are not reflected by the D layer but suffer loss of energy therein. This is the main reason for absorption of HF radio waves, particularly at 10 MHz and below, with progressively smaller absorption as the frequency gets higher. The absorption is small at night and greatest about midday. The layer reduces greatly after sunset; a small part remains due to galactic cosmic rays. A common example of the D layer in action is the disappearance of distant AM broadcast band stations in the daytime.

    During solar proton events, ionization can reach unusually high levels in the D-region over high and polar latitudes. Such very rare events are known as Polar Cap Absorption (or PCA) events, because the increased ionization significantly enhances the absorption of radio signals passing through the region. In fact, absorption levels can increase by many tens of dB during intense events, which is enough to absorb most (if not all) transpolar HF radio signal transmissions. Such events typically last less than 24 to 48 hours.

    Resource Links:

  • The Daedalus Solar Radio telescope is an automated, 40khz radio telescope located in Calgary, Alberta, Canada.
  • Wikipedia entry on radio propogation:

    Supersid System Log

  • 20170209 - working well for many months now, with antenna 30m away from the house, out in the vegetable garden and the data logging computer in the greenhouse, 10m away from the antenna.
  • 20161108 - still working out kinks in the processing code
  • 20161020 - Correct data processing error.. have been processing the same data into graphs since 20161004!
  • 20160805 - We've been losing wifi connectivity with the SuperSID system since it moved out into the back gardens. A WiFi extender was installed yesterday and we are starting to get data again! Y axis scale moved from max 50 to 100
  • 20160715 - moved supersid antenna out to garden, well away from house, linked with a 50' RG58 cable to the netbook linked with wifi
  • 20160302 - successfully uploading data to stanford for a week now. Using only 3 stations and even then we do not appear to be picking up North Dakota or Washington State. This may change when we move the antenna out of the RF shadow of the house later in the spring, so we will keep those two stations up for now.
  • 20160201 - moved the antenna and computer outside onto a covered deck, antenna with a clear view of the eastern horizon.
  • 20160104 - built the loop antenna with 24 gauge enamelled (insulated) wire on a 1" PVC frame with arms of 2m length. The circumference of this was 5.6m and we got 24 turns out of the spool of wire we had. This was connected to a terminal block on the mast. an RG58 coax cable attached to the terminal block at one end and the supersid receiver on the other. The Supersid receiver is a newer model, powered by a 5vdc USB plug, with an audio jack to plug into a computer system. The sound card must support 96KHz sampling as 44 KHz does not get good results (we tried). Software was provided (supersid 1.2.2) and takes a reading every 5 seconds for 24 hours and then saves out the data to file. This does not show an x-axis time chart but rather an x-axis frequency chart, with intensity up the y-axis.