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NRAO June 27-30, 2004. SARA 2004 CONFERENCE. Plasma Bubble Detection & Analysis at 20 MHz. Professor John C. Mannone Professor Wanda Diaz Central Piedmont Community College University of Puerto Rico Duke-Cogema-Stone & Webster Department of Physics

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NRAO June 27-30, 2004

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June 27-30, 2004








20 MHz

Professor John C. Mannone Professor Wanda Diaz

Central Piedmont Community College University of Puerto Rico

Duke-Cogema-Stone & Webster Department of Physics

Charlotte, NC San Juan, Puerto Rico

Spectral Analysis Techniques Developed

SARA Conference July 2003

Solar Physics with 20 MHz Antennas

Focus on Solar Flares

Understanding Solar Radio Propagation Encounters

Frequency Analysis Computer Simulation

Website Creation Sept 2003

NASA/Radio Jove Bulletin Article October 2003

ORION Lecture October 2003

Solar-Ionosphere Connection

Simultaneous Comparative Solar Burst Analysis

Development of Radio Scintillation Experiments

SARA Conference June 2004

Plasma Bubble Detection & Analysis



Charge deficient holes in the F-region, called plasma bubbles, are typically detected above the equatorial zone. Some of the traditional techniques of detection involve sensitive receivers called riometers tuned to 30 MHz to record time variations or  rocket-borne Langmuir probes measure the fluctuation of electron number density.In this work, the electron number density variations are recorded indirectly. Astrophysical radio waves are modulated by these variations as they travel through the ionosphere.  Spectral analysis of decametric radio signals acquired with 20 MHz antennas will provide similar information about the ionosphere. The behavior of the radio noise floor will show if radio light is scintillated. This technique is applied to data from Puerto Rico. Though just north of the magnetic equatorial zone,power spectra disclose radio twinkling by the sudden post-sunset onset of plasma bubbles just before local midnight.

Irregularities and Radio Scintillation

Optical Twinkle- Variation refractive index caused by fluctuations in mass density in the turbulent atmosphere (troposphere)

Radio Twinkle- caused by random fluctuations in electron number density in the ionosphere

Important in



Pulsar Research

Science & Industry Radio Scintillation Detection

30 MHz Riometer- very sensitive low noise receiver and 4-element Yagi arrays

Radar Backscatter

Satellite Transmission- FLEETSAT (254 MHz), GPS Satellites (~1.2 - 1.6 MHz)

Rockets Instrumented with Langmuir Probes- ne fluctuations

Global UV Imager maps ionospheric ions fluctuations (volume emission rate in the far UV at 135.6 nm, due to the radiative recombination of the F-layer predominant ion O+, is proportional to ne2)

Our Methodology on Radio Scintillation Detection

The extent of amplitude modulation of 20 MHz galactic radio background noise by the medium in its path(not necessarily restricted to the ionosphere) is determined and compared with known characteristics.

The signal is too noisy to see the scintillations directly with the simple inexpensive receiver and phased array dipoles used; however, spectral analysis reveals the behavior of the noise floor.

In concert with additional information, such as the time and location of the disturbance, geomagnetic activity, space weather, etc., the spectral analysis is a good tool that will help determine or corroborate the state of the ionosphere.

The Ionosphere is a Plasma

Hot Plasma

Electric and Magnetic Fields Govern the Solar Plasma

Radio Emission Mechanisms


Thermal (Coulomb Scattering)

Non-thermal (Synchrotron Radiation)


Atom Transitions (High Rydberg States)

Hyperfine Transition ( 21 cm spin-flip)

Molecular Transitions (methanol lines; water masers)

Adapted from Fig. 6.2 Atmospheric Window and Sky Brightness (NRAO library)

p = -0.65

Radio Spectra

of Various Sources


Frequency, MHz

Anatomy of the Ionosphere

Layout, Composition, Formation

Dynamics of Fields and Sources (g, E, B, v, P, m, n, j)

Connectivity/Nonlinear Dynamics

Boundary Flows/Shocks

Space Weather/Terrestrial Weather (El Nina South Atlantic Oscillation, Hurricanes)

Diurnal, Seasonal, Solar Cycle Effects

Exosphere (space weather)

40,000 miles / 64,400km

(contains Plasmasphere & Magnetosphere)


50 miles / 80km


400 miles /640km

(Ionosphere straddle these two spheres)


~30 miles / 50km

Troposphere (neutral atmosphere/weather)

5 miles / 8.1km at poles

10 miles / 16.1km at equator

Solar Wind Deforms Earths Dipolar Magnetic Field

A constant stream of particles flowing 106 mph from the Sun’s corona extends beyond Pluto’s orbit.

(106 cm3 = 1 m3 )

Note: green line is for Martian ionosphere

Chapman profile 120 km, max ne = 5x104cm-3

Ionospheric Plasma

Formed from complex collision dynamics and photo-ionization of air molecules involving cosmic rays and UV light.

Transparency of Earth’s Atmosphere

O2 and N2 absorb all l < 290 nmH2O and CO2 block 10m to 1 cm

Universe, 5th ed. Kaufmann and Friedman

Electron Plasma Frequency- Radio Wave Passage

Or the Langmuir Frequency of Plasma Oscillation

wpe = (4pe2n0/me)1/2

~15 MHz

on the day side of the earth near sunspot maximum and

~10 MHz

on the night side near sunspot minimum

Layer opaque to all lower frequencies

Significant Ionospheric Scintillation

of Radio Waves

Caused by Plasma Instabilities

Polar/Auroral Zone

Particle Precipitation

Equatorial Zone

Plasma Plumes and Bubbles

Mid Latitudes

Storm Enhanced Density (SED) from high latitudes

Sudden Storm Enhancement (SSE) from low latitudes

Plasma Plumes and Bubbles

Equatorial ionosphere illustration

Coupled Ionosphere-thermosphere forecast model

Linked to theoretical growth-rate model (left)

Linked to non-linear plasma bubble evolution (right)

Rayleigh-Taylor Instability


E x B Drift


Improved version over Radio Jove RJ1.1 receiver, the RF-2001A is used here (also designed by RF Associates, Dick Flagg)

Local oscillator generates a waveform at frequency around 20.1 MHz.  The range of frequencies to tune at 19.950-20.250.  The JFET transistor amplify incoming signals by a factor of 10.  The receiver input circuitry is designed for a 50 Ohm antenna.

The double dipole antenna ( Radio JOVE) is 10 feet above the ground, aligned east-west, in-phase so the beam is directly overhead. The maximum gain for a horizontal dipole is 7.3 dBi. Beam width is 115 degrees.  The VSWR  is below 1.5:1

Receiver noise figure < 5dB ( 620K).  At the operating frequency of 20.1 MHz the galactic background temperature on the order of 50,000 degrees (this is consistent with the plasma temperature vs. ne chart). 

Can Equatorial Plasma Bubbles be Detected?

Phenomena normally in the equatorial zone

+/- 20 degrees from the magnetic equator

Most southern participating site is Puerto Rico with

Geographic latitude 18.3N, but Geomagnetic latitude 28.2 N

Data was collected hourly for a period before sunset to after sunrise (6 AM to 6 PM Atlantic Standard Time). Arbitrarily, the antenna signal was sampled for the first 10 minutes of each hour. The sampling rate was 1 Hz.

Though the bubbles only survive around 30 minutes, the antenna is seeing numerous irregularities. (Future experiments will acquire more data over a shorter time interval and at a higher sampling rate).

Greatly exaggerated for clarity

Plasma irregularity

Radio wave path

Simple trigonometry =>

sin(q-b)/sin(p-q) = R/(R + z)


3 dB

  • is angle between the vertical and the half power antenna beam width

  • b is the maximum latitude displacement

  • To see an irregularity at height z (typically 600 km)

  • R is the radius of Earth: 6378 km


Antenna site

Latitude of zenith point



Questionably in the Zone:

need 8 degrees (28-8 = 20), may only have 3 degrees latitude

E-W phased dipole array with a 60 degree full beam width

and disturbance at 600 or 1100 km, allows no more than 2.8 or 4.8 degrees latitude difference, respectively. (E-W anti-phase

arrangement is preferred allowing 13-19.5 degree reprieve)

This configuration falls short. However, a free dipole array was assumed.

With the antenna 10 ft (3 m) above the ground (1/5-wavelength), the antenna pattern may become distorted. Though less sensitive, it may now see into the equatorial zone similarly to the anti-phase capability.

Dipole pattern

free space vs. close to the ground

  • Preliminary Data Reduction Sequence

  • Radio Skypipe Pro software SPD files converted to TXT files

  • -Save data in Word document which automatically delimits the data into 3 columns: date, time, signal strength

  • -Correct logging errors

  • (37:.94 must be changed to 37:0.94;

  • often jumps at the minute intervals; other errors in format or placement)

  • -Copy data into Excel and format illegible data

Data Collection &Preparation

-Note that Excel truncates the Hour in Column B. Therefore, label column as time, min:sec after the hour (e.g., after 22Z). However, computations in Excel will treat this a fractional day.

-Compute sampling interval time (in seconds) in cell D4 type


-Plot Signal Strength vs. Time to reproduce the time series.

-Compute sampling statistics

-Load FFT capability in Excel by executing the submenu path

Tools/Add-Ins/check Analysis Toolpak/OK

-Excel algorithms require exactly 2N data points for FFT, Use 512. 1024, etc not to exceed 4096.. Truncate or pad as necessary.

Sampling Statistics

-Perform FFT (Tools/Data Analysis/Fourier Analysis/OK):

Input the range of data for the signal strength matching 2N points; e.g., C4:C515; direct output, e.g., F4:F515

-Decimate the frequency according to N. That is, step-wise increase the frequency (sampling frequency/N).

-Calculate spectral power: square the magnitude of the complex number returned by the FFT (=IMABS(F4)2); propagate to N/2 -1 points to avoid reflection of results.

-Plot Power Spectrum: Power vs. Frequency.

-Scale the plot down by a factor of around 104 to105 to see the spectral components above the noise.

-Plot Log Power vs. Log Frequency with close attention to the 100 to 1000 millihertz range for behavior of the noise floor.

Spectral Analysis

Left Portion of Excel Spreadsheet Analysis

Spreadsheet Calculations

The frequency is stepped in about 2 mHz increments (step = sampling frequency/N = 990 mHz/512 samples)

Right Portion of Excel Spreadsheet Analysis

Spreadsheet Calculations

20 MHz Radio Background Noise

University of Puerto Rico, June 6, 2004 11 PM local time

Apparently uneventful

radio noise, just a dc off-set

Signal Strength vs. Time Graph Reconstruction in Excel

10 minute time series sampled at 1 Hz (990 +/- 7 mHz)

Typical Power Spectral Density (Power vs. Frequency)

not very revealing except for ringing

Diffraction and Scattering Models p1

Scintillation caused by change in refractive index, n, caused by diffraction on irregularities related to electron number density fluctuations or atmospheric turbulence.

(Appleton-Hartree equation)

Irregularity size >> wavelength, wave front is disturbed, get random phase modulation; further modulation occurs before it reaches the antenna => complicated diffraction pattern.

Temporal variation if source is moving relative to the receiver.

Diffraction and Scattering Models p2

Phase screen, simplest model: irregular layer replace by equivalent thin screen a distance z to the antenna (multiple screen are necessary for extended medium and an inhomogeneous background).

Fresnel Diffraction leads to power law frequency dependence f-pwhere p is the spectral index.

Various types of scintillation lead to different spectral indices: the quiet sky 0.65, typical ionospheric scintillation 8/3 (2.5), plasma bubbles range 2-8 with average 4, tropospheric scintillation 11/3, interstellar scintillation like ionospheric without the seasonal or geographic restrictions.

Spectral Analysis

Fresnel Zone Speed of rising plasma bubble is estimated from the corner frequency fc: (V = (lz)1/2 fc)

Spectral Index, p obtained from log Power vs. log frequency plot after the roll-off (around 50 millihertz) to about 1 Hz or perhaps 2 or 3 for very strong scintillation (cut-off frequency for Fresnel filtering). Therefore, spectral behavior is examined from about 100-1000 millihertz.

S4, Scintillation Index (normalized time averaged signal strength) (not a good index for our experiment since our receiver is not sensitive like a riometer).

Spectral index p = 4 for plasma bubbles

over Varanasi, India

Ionospheric Plasma by VHF Waves, R.P. Patel, et al

Pramana Journal of Physics, India Academy of Sciences, Vol 55, No. 5 & 6, Nov/Dec 2000, pp. 699-705

Spectral index p = 5 for plasma bubbles

over San Juan, Puerto Rico

Before and After the Irregularity

log power vs. log frequency

Time Variation of Spectral Index

June 6, 2004 6 PM

June 7, 2004 8 PM

9 PM

11 PM

6 AM

June 6, 2004 sunset 6:57 PM 23Z = -01Z 6/7/04

June 7, 2004 sunrise 5:48 AM = +10Z 6/7/04

Significant change in slope suggests multiple phenomena

50 100

1000 mHz

Corner frequency 316 mHz relates to the first Fresnel zone

Size and speed of irregularity can be estimated from this

A major change is indicated in the condition of the ionized layer

during the measurement interval.

Each linear segment is analyzed between 100 and 1000 mHz,

the correct range for scintillation observations (the “trend line” feature in Excel is used to obtain an unbiased linear regression)

Diurnal Variation of Plasma Bubble Growth

Radio sky background

spectral index -0.65

Post-sunset (-01Z) and Pre-midnight (+04Z) Growth

of Suspected Plasma Bubble

View of Eastern Sky/Milky Way from Puerto Rico June 6, 2004 11 PM

Geomagnetic Activity May Enhance the Occurrence of Irregularities

in the Mid-latitude Region

Geomagnetic coordinate treated in this page is "geomagnetic dipole coordinate" referring to the geocentric dipole field approximating the geomagnetic field based on International Geomagnetic Reference Field (IGRF). The poles are the intersections of the dipole axis with the Earth's surface at (79.5N, 71.6W) and (79.5S, 108.4E)(IGRF 2000), and move slowly according to "secular variation of the geomagnetic field".

Geomagnetic latitude and longitude are defined as shown in the illustration.

HAARP Flux Magnetometer

"H" component positive magnetic northward

"D" component positive eastward

"Z" component positive downward

Geomagnetic storminess is usually indicated in oscillatory variations in the earth's magnetic field. Additional detail concerning the nature and severity of the ionospheric disturbance can be found through analysis of the three components of the field.

The Geomagnetic Disturbance Storm Index

Dst (nT)

During a typical geomagnetic storm the magnetic field is depressed (H component is negative) everywhere in the middle and lower latitudes of the Earth.

From Some of my Radio Astronomy Web Resources

“Adventures in Astronomy by John C. Mannone”

Society for Amateur Radio Astronomers (SARA)

NASA Project Radio Jove

Space Physics & Aeronomy on the Web

Solar X-ray & Geomagnetic Storm Monitor

Sun-Earth Connection Data Availability Catalog Mission Overview Matrix

WIND Daily Spectrogram Plots and Type II & IV Solar Burst Lists


The Sun Now

SOHO Instruments

Solar & Heliospheric Weather Model (IMSAL)

Solar Physics on the Web

Latest Solar Events

Yohkoh GOES Data Base Browser

Australian Space Weather Agency


Storm Enhanced Density

SED is the ionospheric signature of the erosion of the outer plasmasphere by ring current-induced disturbance electric fields. The low-altitude ionosphere: appearance of sunward-convecting regions of enhanced plasma density at mid latitudes.

Millstone Hill incoherent scatter radar has observed SEDs in the pre-midnight sub-auroral ionosphere during the early stages of magnetic storms.

These high-TEC plumes of ionization appear at the equatorward edge of the mid-latitude ionospheric trough and stream sunward driven by poleward-directed electric fields at the equatorward limit of region of sunward convection.


High TEC observed northern Florida ( July 15, 2000 Kp=9 event) and the north-central USA is more typical of pre-midnight SED events for Kp=5 or 6.

Snapshot of SED plume in the post-noon sector obtained vertical TEC from > 120 GPS receiving sites during a 15-min interval. Red contour denotes the instantaneous position of the SED/TEC enhancement.


-spectral analysis of radio signals provides a potential probe of the intervening media the wave propagates through

-inexpensive and extensive equipment and readily available resources renders this favorable to amateur radio astronomy

-state of ionosphere can be examined by monitoring the radio noise floor as a function of time in concert with space weather and geomagnetic parameters

-major irregularities like SEDs and plasma bubbles can be detected in midlatitudes

-June 7 decametric data clearly shows the evolution of an irregularity that fits the characteristics of a plasma bubble over Puerto Rico. Geomagnetic conditions were not remarkable.

Radio Poetry


John C. Mannone

Plasma Bubbles

The furious light sinks below

And air above is tempered so

And not just anywhere this air

But somewhere in equator’s care

The daytime heated air is trapped

While colder air on top is zapped

Which tampered atoms’ state of rest

And left as ions their new guest

Hapless misty heavy layer

Grows a wave of Rayleigh-Taylor

At first a ripple, then a wave

Which drive unstable air to crave

The upper reaches-- freedom bound

The bubbles soar to higher ground

Peculiar pockets rising fast

The air had seen a solar blast

Holes large left with charge in trouble

Rising high as plasma bubbles

Gently urged by E cross B

These fickle fields that they do see

Not seen with ocular bore

But quivers in the radio floor

Bubbled pockets confuse the ray

Frantically bend it everyway

And when still dark and very late

The plasma plumes do dissipate

No longer there in hassling poise

The radio whispers quite noise.

By John C. Mannone

April 30, 2004


University of Puerto Rico

Wanda Diaz

Tamke-Allan Observatory

David Fields

NASA/Radio Jove Project

Jim Thieman, Chuck Higgins, Leonard Garcia

And many others, but especially…

… My Lord, Jesus the Christ




A Few FFT Basics

The Fourier Transform, FT is an analog tool used to analyze the frequency content of continuous signals.

The Discrete Fourier Transform, DFT is a digital tool used to analyze the frequency content of discrete signals.

The Fast Fourier Transform, FFT is an algorithm to rapidly compute the DFT.

N = total number of discrete samples

T = total sampling time; don’t confuse with period

Dt = time increment between samples = T/N

fs = the sampling frequency = 1/Dt

N is often restricted to powers of 2

Digitizing the analog signal must be frequent to faithfully reproduce it.

Nyquist criterion fsampling> 2fmaximum (Image processing considerations of brightness and contrast suggest a factor of 2.57).

Aliasing (fold-over or mixing) occurs if Nyquist sampling is violated.


(1) Analog electronics: heterodyning is used for tuning; anti-aliasing filters (low pass) filter unwanted signals before the A/D conversion.

(2) Engine timing: slow sampling by a strobe light can arrest the motion of a rotating engine.

(3) Movie making: frames per second may be too slow and “wagon wheels” will appear to stop or rotate backwards.

(4) Moiré patterns: slight motion of one of two overlapping (semitransparent) repetitive patterns creates large scale changes in patterns.

Fourier Transform Examples

Also Gaussian pulse transforms to a Gaussian frequency

Random noise can be modeled as a series of spikes (think of a train of very narrow Gaussians); transforms to huge Gaussian peak due to additive effect and a noisy tail)

Spectral Features Revealed

Power vs. Frequency Plot

Dynamic nature of the ionosphere as well as the history of travel through multiple media affecting the radio wave leads to combs, bands, modulation envelopes. Visualize Moiré patterns from multiple screen models.

Excited cavity modes and other ringing lead to resonant lines: fundamental vibration and its harmonics.

Nonlinear interaction between boundaries may lead to subharmonics.

Radio Jove Archive


Solar Burst Data


March 26, 2002 22:23 Z

Time & Frequency Analyzed in Excel

Radio Noise Floor

log Power vs. log Frequency Plot

The spectral features are superimposed on a radio sky background.

The behavior of this floor is an indicator of the state of the media the radio wave propagates through.

Log-log plots reveal spectral index.



2 x 2 array of 5-element yagi antennas &

very sensitive low noise receiver

Flares and Prominences

Solar flares are tremendous explosions on the surface of the Sun. A billion megatons of TNT energy release across the entire electromagnetic spectrum in just a few minutes.

Coronal Mass Ejections


Disruption of flow of the solar wind, compresses magnetopause magnetic fields

dB/dt => strong currents induced on power grid

Coronal mass ejections are often associated with solar flares and prominence eruptions but they can also occur in the absence of either of these processes.

Space Weather Forecasting

Measurement and Modeling Requirements

Living with a Star Measurements Workshop

NASA Goddard Space Center

February 9-10, 2000

Gary Heckman

NOAA Space Environment Center

SEC Users

Space Weather



Geomagnetic field



Energetic particle




Geomagnetic field

Neutral Atmosphere

Energetic Particles

Solar activity evolution--observations and models

Observing and Modeling



Solar EUV and X-ray Flux





Energetic particles






interaction models

In-situ observations and models within each domain

Verification is a critical function

Solar Measurement Priorities

  • CME initiation in 3 dimensions to drive interplanetary models

  • Direction

  • Radial velocity

  • Structure and configuration

  • Coronal Holes—observation and prediction of Earth impact

  • EUV/X-ray flux—observation and prediction

  • Evidence of energetic particle acceleration and interplanetary injection

  • X-ray flares and radio bursts—observation and forecasting

  • Evolution of active structures--prediction

  • Cycle evolution--prediction

Equatorial Scintillation

Polar-Orbit Sun Synchronous

Solar X-ray/EUV sensors

Solar X-ray/EUV Imager

Solar Coronagraph

Solar Wind on Sun-Earth line

Particles and Fields(LEO to GEO to HEO)

Auroral Imager

Stereo Solar Observer

GPS Occultation

Scintillation--Polar and Low Lat

TEC Networks

Ionosonde Sounders

Magnetometer Networks

All Sky Cameras

Solar Optical/Radio

Riometer Chain

Ground-based radars

Satellite Drag Observation





Hard X-ray spectrometer

















Japan L5
















Ops Riometer

SuperDARN Radars

DRAG Observer




Fully Capable Operational System

Operational, funded, or planned

R and D

Observing Gap

Less than fully capable operational system

Early stages of definition or distance into future

lessens confidence of deployment, or no funding

Planned but doubt about deployment

Space Weather Operational Sensors Timeline

Equatorial Scintillation

Polar-Orbit Sun Synchronous

Solar X-ray/EUV Imager

Solar Coronagraph

Solar Wind on Sun-Earth line

Particle Detectors(LEO to GEO to HEO)

Auroral Imager

Stereo Solar Observer

GPS Occultation

Scintillation--Polar and Low Lat

TEC Networks

Ionosonde Sounders

Magnetometer Networks

All Sky Cameras

Solar Optical/Radio

Riometer Chain

Satellite Drag Observation









Solar Polar Imager



Solar Wind Monitor

Solar Wind SENTRY





GOES n/q

Magnetospheric Constellation




Japan L5














OPS Riometer


DRAG Observer

R and D

Observing Gap

Fully Capable Operational System

Less than fully capable operational system

NOAA current, planned, or potential sensor or satellite set of sensors (e.g. GOES = GOES SEM)

Note: this version of the plan has not incorporated sensors from the NASA-interagency initiative Living with a Star

New Operational Measurement Priorities

Radio Astronomy Web Resources

Society for Amateur Radio Astronomers (SARA)

NASA Project Radio Jove

Space Physics & Aeronomy on the Web


A compilation of useful SOHO and GEOS satellite data are found at "Solar Physics on the Web." Below is a solar storm and geomagnetic storm monitor from the site and a link to it which shows current x-ray and particle flux as well as other data like magnetometer readings.  From

Solar X-ray & Geomagnetic Storm Monitor

(2) A comprehensive listing of NASA space-borne laboratories (ACE, Cluster, FAST, IMAGE, Polar, RHESSI, SAMPEX, SOHO, TIMED, TRACE, Ulysses, Voyager, and Wind) is extractable from the Sun-Earth Connection Data Availability Catalog Mission Overview Matrix. This is an extremely useful table and links to project descriptions and to live and archived data.

SECDAC Mission Overview Matrix

A useful item in the matrix is the link to various homepages and mission matrices for each of the above. These in turn have links to real-time data as well as to archived data. For example,

(3) Follow the links to the WIND spacecraft/WAVES instrument package/Waves homepage for electronic data products. Useful spectrograms of 20-14,000 KHz radio emissions are available from 1994 as well a a listing of Type II & IV solar burst events:

WIND Daily Spectrogram Plots and Type II & IV Solar Burst Lists

(4) Follow the links from the overview matrix to, say, SOHO/GONG/. It will show all the available SOHO data:


Near Real Time Images and Movies, which features 3 of the 12 SOHO instruments:

EIT (Extreme UV Imaging Telescope)

MDI (Michelson-Doppler Imager) Continuum and Magnetogram

LASCO (Low Angle and Spectrometric Coronagraph Experiment)

(4a) The latest solar images with these instruments are found on

The Sun Now

(4b) From the SOHO Data page, choose the specific instruments under "Other Near Real Time Data," which represent other instruments aboard SOHO:

-VIRGO (Variability of Solar Irradiance and Gravity Oscillations)

-Total Solar Irradiance

-CELIAS (Charge, Element and Isotope Analysis System)

-Proton and Energetic Particle Flare Activity Monitors, X-ray Flare Monitor

-ERNE (Energetic and Relativistic Nuclei and Electron) Proton and Helium Intensity

-MDI Far Side Imaging

-SWAN ((Solar Wind Anisotropies) Far Side Imaging

For a description of the 12 SOHO Instruments, see the link below: SOHO Instruments

(4c) SOHO Data page also has the "Other Near Real Time Data" list, which has the particularly useful "Solar/Heliospheric Forecast" and "Recent Solar Activity" subheadings.

(5) Solar/Heliospheric Forecast has many good products including Solar wind model and Virtual Star Lab:

Solar & Heliospheric Weather Model (IMSAL)

(6) From here, the Solar Data link is Solar Physics on the Web, which has comprehensive live and easy-to-use archive database (SOHO, GOES, WIND and the MEES Solar Observatory in Hawaii). Recommend to have some of these open when collecting Radio Jove data.

Solar Physics on the Web

(7) Recent Solar Activity: pinpoint the sunspot group that was active. Choose an event in the time span given, perhaps the strongest X-ray flare (in order of increasing intensity: A, B, C, M, X)

Solarsoft (Lockheed Martin Solar and Astrophysics Laboratory)

Header Information: Event Number, GOES Flare Classification, etc.

Flare sequence images (JavaScript frames w/ GOES flux plotted above)

TRACE event sequences 171A images (JavaScript, GIF Animations, or MPEGs), and Flare locator image

Latest Solar Events

(8) Archived data (item 7) is harder to come by. Solarsoft is developing access to the database. However, the GOES data is easily retrievable back to 1991 from their Yohkoh solar x-ray telescope database:

Yohkoh GOES Data Base Browser

(9) IPS Radio and Space Services provides several excellent resources under their "Space Weather" and "Solar" links. Real time Coolgura (18-1800 MHz) and Learmonth (25-180 MHz) Spectrograms as well as daily historical data up to 3 months (Coolgora). Space weather and ionospheric data is also provided.

Australian Space Weather Agency


A series of graduate level lectures on plasma physics: International Max Planck Research School on Physical Processes in the Solar System and Beyond at the Universities of Göttingen and Braunschweig.

Solar System School

(2) Ground based facilities, like the Alaskan High Frequency Active Auroral Research Program (HAARP). Ionospheric data (real time and archived) is available under the various instruments (Magnetometer, Riometer, HF Ionosound, Total Electron Content, Spectrum Monitor, etc.). See "Scientific Data from the Site" in the Table of Contents below,

HAARP Table of Contents

(3) Services, like those of Northwest Research Associates (NWRA) Space Weather and Ionospheric Scintillation Predictions. Very helpful staff. Site has good links to tutorials.

Space Weather Services

Ionospheric Scintillation Predictions

(4) Products from several weather and lightning satellite databases.

Aviation Digital Data Service

Vaisala Lightning Explorer

(5) Some climatological data to be displayed on a 3-dimensional globe that one can manipulate (a good option but may require a free software download). (to 1995):

The GLOBE Program

Images provided by Weather Services International Corp. (WSI) and NASA though the Global Energy and Water Cycle Experiment Continental-Scale International Project.

Currently Available

1 April 1995 to 18 April 1997, Daily

19 April 1997 to 29 May 2004, Hourly

Select the Radar product in the link below:

NEXRAD Archived Radar

(6) Specialized Databases like the 81.5 MHz Interplanetary Scintillation. Some animations are available for 1990-1993.

Interplanetary Scintillation (IPS) Data

IPS Hammer-Aitoff Projection March 1992

(7) Prediction of Jupiter storms is based on the interaction of the Jovian moon, Io, with the Jovian magnetic field. Professor Kazumasa Imai (Kochi National College of Technology, Department of Electrical Engineering) has prepared a useful prediction tool. This will prove invaluable to assess the potential influence of certain Jovian storms occurring concurrently with a solar burst (this speculation will be defended later).

The Jovian Daily Ephemeris

(8) Solar and Jovian data files from October 1999 (mostly decametric) can be accessed via the link on the Radio Jove homepage (above). It can be directly accessed via "View Current Data Archive," which allows one to specify the fields to view (be sure to mark "Data Products").

Radio Jove Data Archive

(9) Other than to look at picture files of the signal traces in the archive, one will need the SPD wave files to manipulate the data. Radio Sky Publishing has free PC software that allows strip chart recording and sharing files over the internet. The affordable Pro version may be required for some features, like converting the SPD files to TEXT files which can be manipulated in EXCEL.

Radio Sky Publishing/SkyPipe Software

(10) Planetarium software

Starry Night Planetarium Software

Cartes du Ciel (Sky Charts)

SEDS Planetarium Software List

(11) Geographical Information is obtained from several databases when the planetarium software falls short:

USGS Geographic Names Information System

Topographical Maps & Coordinates (Topozone)

Maporama: Lat/Lon for Specific Location

(12) Astronomical information

Greenwich Sidereal Time Calculator (Astro Java)

(13) Geomagnetic Latitude and Longitude

Convert Geographic to Geomagnetic Coordinates

Recorded Radio Signal Differences Explained



Electronic Noise




Antenna Pattern


Local Obstructions Geographic Coordinates

Ground Capacitance

Distance Above Ground

Soil Type


Recorded Radio Signal Differences Explained

Transmission Lines

Impedance Mismatch

Microphonic Cable/Wind Loading

Man-made Interferences

Power Lines

Cycling Electrical Equipment (motors)

Transmitters (Radio, TV, proposed digital phone lines…)

Recorded Radio Signal Differences Explained

Natural Interferences and Phenomena





Radio Twinkling



Schumann Resonances (VLF Earth Cavity)


Coronal Loop Oscillations

Plasma Instabilities


Bunching/Stretching Magnetic Field Lines

Solar Cavity

Resonant “Acoustics”

Tropospheric Scintillation


A rapid fluctuation in amplitude, phase and arrival angle

-Refractive Index

Small irregularities caused by temperature inversions

i.e., reverse of lapse rate due to:

trade wind inversion, frontal inversion,turbulent boundary

Tropospheric Scintillation

-Dry Scintillation: no fading

-Wet Scintillation: causes fading when raining

Absorption Bands

Elevation angle 90°

Latitude 45°N

Water Vapour

22.2, 182 and 325 GHz


60 and 119 GHz

Small losses < 10 GHz

The ionosphere, the closest naturally occurring plasma.

Signals transmitted to and from satellites for communication and navigation purposes must pass through the irregularities in the ionosphere (most common at equatorial latitudes, although they can occur anywhere)

Computer simulations of ionospheric processes (ionospheric model developed at the University of Alaska, Fairbanks.) The development of visualizations of this type have allowed us to see and appreciate the enormous variability and turbulence that occurs in the ionosphere during a major solar geomagnetic storm.

Adapted from “The Importance of Ionospheric Research”

VHF Satellite Scintillation

March 26, 2002 Solar Burst Event 21:23Z

Excerpt prepared for NASA Radio Jove Bulletin; full details on my web site Adventures in Astronomy by John C. Mannone

The Solar-Ionospheric Connection: Physics

with the 20 MHz Antenna

At the 2003 SARA Conference, I discussed the increased utility of the 20 MHz radio telescopes. Systems, such as Radio Jove, can be an interesting probe for both solar physics and geophysics. A variety of resources are used to compare antenna signals originating from the sun. Simultaneous records from several different locations show similar gross features. However, there are differing finer details that present a challenge to reconcile. My new web page,, presents some very useful resources (Radio Astronomy Web Tools) that benefit any effort to understand comparisons of solar bursts (or Jovian storms).

In addition to these comparison tools, a frequency analysis of the antenna signals will reveal even more. There are many things that will affect a radio wave in its path to your antenna. Most notably is turbulence. It causes fluctuations in the solar wind and in our ionosphere. In turn, they cause the radio wave to fluctuate. Even upper level winds in our atmosphere can affect the radio wave in the same way starlight is made to twinkle.

These different kinds of twinkle can be studied by signal processing methods available in Microsoft Excel. The mathematic tool is called an FFT from which a power spectrum is plotted. It reveals these effects on the radio wave and points to the physics causing it.

Radio twinkling is usually studied with more sophisticated equipment and at much high frequencies (~250-1700 MHz) because of their importance in communication, navigation, and pulsar research. The exciting thing here is exploration of “new ground” with the 20 MHz systems; and, we have a virtual global antenna farm to do it with.

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