SCGO Sudden Ionospheric Disturbance (SuperSID) System
Welcome to Starlight Cascade Observatory SuperSID System Project!Near Yarker, Ontario, Canada. (44.22.39 N 76.45.47 W 151M Elevation)
Page Created: 2016 January 04
Page Updated: 2024 March 20
SCGO Home * Allsky1 * Allsky2 * RadioJove * SuperSID * Weather
2024May10 - OFFLINE - SCGO Supersid Data (Updates hourly):
 NAA- Cutler Maine 24.0KHz |  NML- Lamoure North Dakota 25.2 KHz |  NLK- Jim Creek Washington 24.8 KHz |
It takes readings of VLF transmitting stations as they bounce off the ionosphere every 5 seconds, 24 hours a day.
It went operational in 2016 January, replacing an older SID system. We built a new 2m wide 24 loop antenna as well (24 gauge enamelled (insulated) wire on a 1" PVC frame with arms of 2m length. The circumference of this was 5.6m and we got24 turns out of the spool)
Data is archived daily at Stanford University (California USA). It is available for viewing at:
http://sid.stanford.edu/database-browser/
You can see all stations data from a complete day by using this link, customizing the date:
http://sid.stanford.edu/database-browser/browse.jsp?date=2024-02-22T00.00.00
In addition, you can see another station: Moore Observatory
VLF Monitor for Space Weather and Solar Flares, daily images of NAA Cutler Maine USA
 24 loop, 2m antenna |  A peek inside the preamplifier/receiver | |
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Components:
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On 2024February01 we switched back to the windows software supersid v1.2.2
On 2023March05 new superSID code by Steve Berl was installed on a new build of Raspbian Bullseye 64bit OS. Multistation capability has returned as has data logging to the Stanford database. https://github.com/sberl/supersid
On 2021March10 the windows7 based software supersid v1.2.2 was replaced with a raspberry pi 3b and supersid code by Nathan Towne.
https://myplace.frontier.com/~nathan56
So now we have a more reliable data logging device, that takes much less power and never gives a windows blue screen of death.
Raspberry Pi 3 Model B is the earliest model of the third-generation Raspberry Pi. Quad Core 1.2GHz Broadcom BCM2837 64bit CPU 1GB RAM BCM43438 wireless LAN and Bluetooth Low Energy (BLE) on board 100 Base Ethernet 40-pin extended GPIO 4 USB 2 ports 4 Pole stereo output and composite video port Full size HDMI® CSI camera port for connecting a Raspberry Pi camera DSI display port for connecting a Raspberry Pi touchscreen display Micro SD port for loading your operating system and storing data
The data folder has daily entries of .csv data like this:
From http://moondog.astro.louisville.edu/naa/circuit/info.html
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.
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 raspberry pi 3b unit.
NOAA GOES XRay Flux
History
From 2016 January to 2021 March we used a windows 7 netbook running Supersid v1.2.2 for windows as a data logging software.
We monitored three stations: NAA, NLK and NML. The software generated three .csv text data files
NAA.csv, NLK.csv and NLM.csv. The data format in each file looked like this:
# Site = SCO
# Contact = xxx@xxx.com
# Country = Canada
# Longitude = -76.7631
# Latitude = 44.3775
#
# UTC_Offset = -5
# TimeZone = EST
#
# UTC_StartTime = 2016-07-22 00:00:00
# LogInterval = 5
# LogType = filtered
# MonitorID = 9193
# SampleRate = 5
# StationID = NLK
# Frequency = 24800
2016-07-22 00:00:00 0.0465797139616
2016-07-22 00:00:05 0.0457116274316
2016-07-22 00:00:10 0.0448435409015
With some custom linux bash scripting, R and python, and gnuplot, we generated three graphs every day:
On 2021 March we successfully installed the supersid code written by Nathan Towne, but could not get all three stations reporting. Eventually with a lot of trial and error, we got the one station NAA reporting.
NAA
NLK
NML
Our current Header.txt config file consists of:
# Site = SCO
# Contact = xxxx
# Longitude = -76.76
# Latitude = 44.37
# monitor_id = 9193
# the integration time
# loginterval = 5.0
#
# stations = NAA, NLK, NML
# frequencies = 24000, 24800, 25200
# group = naa, 23600, 24400, 1
# transmitter = NAA, 24000, 2, f0, 24000, sig, 47.0, lambda f: np.exp(-((f - f0)/sig)**2/2)
# group = group2, 24350, 25800, 2
# transmitter NLK, 24800.0, 2, f0, 24805.0, sig, 47.0, lambda f: np.exp(-((f - f0)/sig)**2/2)
# transmitter NML, 25200.0, 6, f0, 25200.0, sig, 49.0, f1,
f0+3.8*sig, f2, f0-4.0*sig, sig2, 0.38*sig, g, np.exp(-((f - f0)/sig)**2/2),
lambda f: g/(1+0.05/g) + 0.006*np.exp(-((f - (f1))/(sig2))**2/2) + 0.006*np.exp(-((f - (f2))/(sig2))**2/2)
# transmitter = NML, 25200.0, 2, f0, 25200.0, sig, 72.0, lambda f: OrthPoly.silineshape((f - f0)/sig)**2
The software starts on booting up using a cron job command:
@reboot /home/pi/startsidmon &
The command consists of:
cd sidmon
./sidmon.py -d plughw:CARD=Device -lp 1
The data syncs to a linux server once an hour
: 1 * * * * /home/pi/0sync
Which consists of:
rsync -auvx /home/pi/sidmon/data/*.csv pi@192.168.1.10:/web/supersid/data
rsync -auvx /home/pi/sidmon/*.txt pi@192.168.1.10:/web/supersid
rsync -auvx /home/pi/sidmon/*.hist pi@192.168.1.10:/web/supersid
-rw-r--r-- 1 pi pi 457527 Nov 26 13:23 20211126Ch0.csv
-rw-r--r-- 1 pi pi 609865 Nov 25 19:00 20211125Ch0.csv
-rw-r--r-- 1 pi pi 618958 Nov 24 19:00 20211124Ch0.csv
-rw-r--r-- 1 pi pi 614219 Nov 23 18:59 20211123Ch0.csv
The data file looks like this:
2021-11-25 23:59:47.96,199930.8,-414.1
2021-11-25 23:59:53.58,228243.1,339.7
2021-11-25 23:59:59.20,226557.2,-2386.6
Which does appear to have three values.. only some of them are negative?
Intro
Supersid is a newer multifrequency Sudden Ionospheric Disturbance detection system available from http://solar-center.stanford.edu/SID/sidmonitor/
References
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
LaMoure, ND NML 25.2 500
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.
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.
data logging win7 notebook - replaced with a raspberry pi 3b on 2021march10th.