Ionospheric Sounding Study

DPS-4D EI764 064 / 64.630750, -147.042904

Propagation for Snipers Net 3920 KHz 0200 UTC



IMPORTANT: Please read Rules of the Roadfor license information and refer to Acknowledgements List to use GIRO data per license requirements

Select Station or Calendar list above to access ionogram images

For access to numerical data in DIDBase, install SAOExplorer



with Real-Time & Retrospective HF Ionospheric Sounding Data from Lowell DIDBase

The Lowell GIRO Data Center (LGDC) implements a suite of technologies for post-processing, modeling, analysis, and dissemination of the acquired and derived data products:

  • IRI-based Real-time Assimilative Model, “IRTAM”, that builds and publishes every 15-minutes an updated “global weather” map of the peak density and height in the ionosphere, as well as a map of deviations from the classic IRI climate;
  • Global Assimilative Model of Bottomside Ionosphere Timelines (GAMBIT) Database and Explorer holding 15 years worth of IRTAM computed maps at 15 minute cadence;.
  • 17+ million ionograms and matching ionogram-derived records of URSI-standard ionospheric characteristics and vertical profiles of electron density;
  • 10+ million records of the Doppler Skymaps showing spatial distributions over the GIRO locations and plasma drifts;
  • Data and software for Traveling Ionospheric Disturbance (TID) diagnostics; and
  • HR2006 ray tracing software mated to the "realistic" IRTAM ionosphere.

In cooperation with the URSI Ionosonde Network Advisory Group (INAG), the LGDC promotes cooperative agreements with the ionosonde observatories of the world to accept and process real-time data of HF radio monitoring of the ionosphere, and to promote a variety of investigations that benefit from the global-scale, prompt, detailed, and accurate descriptions of the ionospheric variability.


Current and prospective sites with inputs to assimilative models

1. Select Time Interval:

All times in UTC

3. Select Data to Download:

Control-click to select multiple characteristics
 Visit DIDBase Portal for data availability 
 (live scan of DIDBase, wait for reply)

2. Pick one GIRO Location:   

Compute MUFD for  km

Link Station






List of years for EIELSON 
List of years for GAKONA

Strongest solar flare in over a decade
on 07 September 2017. Posted in Space Science

From the Regional Space Weather Warning Centre of the South African National Space Agency

For Immediate Release

Hermanus, South Africa, 08.09.2017

SA Space Agency monitoring strongest solar flare in over a decade  

Our life giving star, the Sun, has unleashed two massive solar flares, the second of which is the strongest flare in over a decade. The burst of radiation was so intense, it caused high frequency (HF) radio blackouts across the daytime side of Earth affecting HF communication over Africa, Europe and the Atlantic Ocean.

The first flare erupted on 6 Sep 2017 from active region 2673 and measured in at X 2.2. Hot on its heels, another flare blasted off the Sun three hours later, measuring in at a whopping X 9.3 - the most powerful flare since 2005.

Solar flares are giant explosions on the surface of the Sun that occur when twisted magnetic field lines suddenly snap and release massive amounts of electromagnetic energy. Five categories — A, B, C, M and X — are used to rank solar flares based on their intensity. A-Class flares are the weakest, while X-Class are the most energetic.

The solar flares were accompanied by a coronal mass ejection (CME) which travelled towards Earth at speeds over 1200 km per second and impacted the Earth's magnetic field early morning on 8 Sep 2017. The impact of the CME has sparked a strong (G3) geomagnetic storm on Earth which can have effects on HF communication, power grids, navigation systems such as GPS, and communication systems such as DStv, mobile phones and internet connectivity. Moderate disturbances are expected at this stage. The storm will gradually subside over the next 24 hours



Strongest flare reported in the last 24 hours was the X8.2 flare which
peaked at 16:06 UT, on September 10. This long duration flare, originated
from the Catania sunspot group 46 (NOAA AR 2673) which was, at the moment
of eruption, already partially behind the west solar limb. The flare was
associated with the EIT wave, halo CME and the shock wave which had
projected speed of about 2900 km/s. 
The steep increase of the proton fluxes, with >10 MeV, > 50 MeV as well as
>100MeV, associated with the X8.2 flare was observed yesterday. The proton
flux levels are slowly decreasing, but they are presently still above the
event threshold.The recently arrived data indicate that the arrival of the
CME-driven shock wave, associated with the X-class flare, might be expected
tomorrow morning (probably around 08:00 UT).
The Catania sunspot group 46 (NOAA AR 2673), which was the source of the
majority of the flaring activity during last few days, has rotated behind
the west solar limb. Therefore, we expect solar activity to be low, with at
most C-class flares. 

The solar wind speed remains to be rather high, amounting about 600 km/s,
and the interplanetary magnetic field magnitude is about 4 nT. The fast
solar wind, associated with the low latitude coronal hole in the northern
hemisphere which reached the central meridian in the mid-day yesterday, is
expecting to arrive at the Earth on September 13.
Geomagnetic conditions are presently quiet to unsettled. We expect active
conditions within next 24 hours due to arrival of the CME-driven shock

These IRTAM maps have been made possible due to real-time data provided by:

US Air Force Weather Agency


Australian Government Bureau of Meteorology


Institute of Geology and Geophysics Chinese Academy of Sciences


National Institute for Space Research


Istituto Nazionale di Geofisica e Vulcanologia




Jicamarca Radio Observatory JRO


Idaho National Laboratory


National Institute For Aerospace Technology, INTA


Royal Meteorological Institute of Belgium


 Leibniz-Institute of Atmospheric Physics e.V. at University of Rostock (IAP)


UiT The Arctic University Of Norway

National Observatory of Athens


Air Force Research Laboratory


South African National Space Agency, SANSA


YuG Shafer Institute of Cosmophysical Research and Aeronomy


Pushkov Institute of Terrestrial Magnetism Ionosphere and Radio Wave P


National Radio Research Agency


Ebro Observatory


Rutherford Appleton Laboratory RAL


Institute of Atmospheric Physics ASCR

Universidad Nacional de Tucuman UNT


Frederick University


UML Space Science Lab


Space Research Centre Polish Academy of Sciences


University Of Floridia

Global Ionospheric Radio Observatory, (GIRO) Lowell Digisonde International, LLC University Of Massachusetts Space Science Lab

IRI Real-Time Assimilative Mapping (IRTAM)

Global Near-Real-Time F2-layer Critical Frequency and Peak Height