Accession Number:

ADA516755

Title:

Understanding and Forecasting the Sun's Impact on the Battlespace Environment

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

• Lean, J. L.
• Picone, J. M.
• Emmert, J. T.
• Dahlburg, J. P.

Report Date:

2007-01-01

Pagination or Media Count:

4.0

Abstract:

The battlespace environment extends far above the surface of the Earth. Of special importance are the outer layers of the Earths atmosphere, from altitudes 100 to 1000 km, where there is sufficient mass to impede the motion of Earth-orbiting spacecraft, and where layers of charged particles control the propagation of radio waves. Changes in atmospheric drag alter the orbits of the thousands of space objects in low Earth orbit LEO that are tracked by the U.S. Space Command. The ionosphere transmits, reflects, retards, and refracts kHz to MHz radio wave frequencies. As a result, fluctuations in the neutral and ionized environment can negatively impact Naval operations by disrupting communications and navigation and by degrading radar accuracy, targeting precision, and orbit prediction. The Sun is the primary source of variations in the neutral and ionized upper atmosphere. A suite of new solar and atmospheric data bases that extend over the Suns 11-year activity cycle are now refining our understanding of the intricately interconnected Sun-Earth system, thereby improving the ability to predict this regions impact on DoD systems. The new data bases include solar imagery from NRL instruments aboard the Solar Heliospheric Observatory SOHO, daily thermospheric mass density derived from spacecraft drag via a new NRL algorithm, and total electron content obtained from analyses of GPS timing by the Center for Orbit Determination in Europe CODE.

Descriptors:

• *SOLAR ULTRAVIOLET RADIATION
• *SUN
• *UPPER ATMOSPHERE
• *ATMOSPHERIC DENSITY
• *RADIO TRANSMISSION
• *NAVAL OPERATIONS
• *WEATHER FORECASTING
• ELECTRON DENSITY
• IMAGES
• NAVAL RESEARCH
• COMMUNICATION AND RADIO SYSTEMS
• DRAG
• EARTH(PLANET)
• RADAR INTERFERENCE
• FLUX(RATE)
• BATTLEFIELDS
• LOW ORBIT TRAJECTORIES
• EARTH ORBITS
• SPACECRAFT
• HIGH FREQUENCY
• DATA BASES
• REPRINTS

Subject Categories:

• Astrophysics
• Atmospheric Physics
• Meteorology
• Military Operations, Strategy and Tactics
• Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE