Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Very Low Frequency Remote Sensing of the Ionosphere and the Radiation Belts Using a VLF Beacon Transmitter at South Pole  (VLF Beacon Transmitter at South Pole)

Outline
A VLF Beacon Transmitter at South Pole is used for the purpose of continuous measurement of both steady and burst precipitation of relativistic (>300 keV) electrons from the Earth's magnetosphere. The relativistic electron population as measured at geosynhronous orbit exhibits pronounced fluctuations in association with substorm and solar activity. However, little is known about the extent of associated precipitation into the ionosphere. When they do precipitate, these highly energetic electrons penetrate to altitudes as low as 30-40 km, producing ionization, x-rays and possibly affecting chemical reactions involving ozone production. The extent of relativistic electron precipitation is measured by means of associated amplitude and phase variations on a subionospheric VLF Beacon signal transmitted from South Pole and received at various Antarctic stations. The primary receivign site is at Palmer Station, Antarctica, but the beacon signal is detectable at all of the coastal Antarctic Stations. The availability of the South Pole VLF beacon has the potential to synergistically enhance other Antarctic Upper Atmospheric research efforts, such as the Automatic Geophysical Observatory programs. The proposed program also strongly complements ongoing satellite based measurements of trapped and precipitating high energy electrons both at low and high altitudes. The beacon transmitter will transmit at 19.4 kHz, radiating ~200 W of total power with a ~6.25 km (tip-to-tip length) long horizontal dipole antenna. The VLF beacon operates under computer control with a synoptic schedule of ~1 min out of every 15 min.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
he project has the potential to produce new understanding of the acceleration and loss of energetic radiation belt particles, thereby enabling the quantification of a major practically important component of Space Weather.

What international collaboration is involved in this project?
The international collaboration potential is very significant; the VLF Beacon transmits a highly coherent VLF signal at 19.4 kHz at 15-min intervals. The signal is strong enough to be observed with VLF receivers all across the Antarctic continent, at the various coastal stations of the different countries.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Palmer and South Pole Stations

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: 01/06 – 12/08            

Significant facilities will be required for this project:
The transmitter utilizes a very long (7.5 km) horizontal antenna deployed on a thick ice sheet. This antenna is already in place, and can be used with very little maintenance.

Will the project leave a legacy of infrastructure?
Yes, the VLF beacon transmitter at South Pole is a facility instrument that can be used in the long term to monitor relativistic electron precipitation as an important proxy measure of Space Weather.

How is it envisaged that the required logistic support will be secured?
Consortium
Own national polar operator

he major infrastructure component is the VLF transmitter which is located at South Pole. However, for full implementation of the program concept, the transmitted beacon signal should be received and recorded at the various Antartic Stations of the participating countries. These types of receivers are quite simple, and they alreday exist at many of the stations (e.g., Halley, Sanae, Syowa), but their operation and maintenance should be covered by the corresponding national polar operators. For some other sites (e.g., Davis, Casey), receivers need to be installed; these receivers can be provided by Stanford University at very low cost, but once again they have to be installed/maintained under the support of the relevant national polar operators.

Has the project been "endorsed" at a national or international level?
Yes, the VLF Beacon Transmitter at South Pole is a funded project, which is completing its first three year term at the end of 2005. A new proposal will be submitted (in June 2005) to the National Science Foundation to extend its operation for 3-5 more years, and to enhance its capabilities. The international collaboration component has also started; for example, the VLF beacon transmissions from South Pole are regularly received at the Halley Station of the U.K., and they have also been opbserved at Sanae (South Africa).

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
Expansion

The South Pole VLF Beacon has been in operation since November 2003.

How will the project be organised and managed?
On the United States side, the transmitter at South Pole and the primary receiver at Palmer Station is to be suppported under the auspices of the Office of Polar Programs of the National Science Foundation. The Principal Investigator for the project is Professor Umran Inan of Stanford University.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
There is a lot of potential for this. Many amateur radio operators have already contacted us to find out the schedule of transmissions, so that they can search for the signal. This is a rather unique signal at 19.4 kHz, highly coherent, and is produced for 1-min every 15-mins. Simple receivers can be provided to the public to measure the signal.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Primary data from Palmer Station (i.e.,g the phase and amplitude of the Beacon signal as measured at Palmer) will be made available via Internet in near-real-time. Data from other (non-U.S.) sites can also be made available, depending on the infrastructure.

How is it proposed to fund the project?
On the United States side, the transmitter at South Pole and the primary receiver at Palmer Station is to be suppported under the auspices of the Office of Polar Programs of the National Science Foundation.

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Prof Umran Inan
Packard Bldg Rm 355, 350 Serra Mall
STAR Laboratory, Electrical Engineering Department
Stanford University
94305-9515
USA

Tel: 650-723-4994
Mobile: no
Fax: 650-723-9251
Email:

Other project members and their affiliation