(U) Ionospheric Effects on Communication/Navigation Systems

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)

Overview: (U)
(U) This subthrust advances Air Force war fighting capabilities by providing technology to understand, mitigate, or exploit the interactions between military systems and the neutral atmospheric and ionospheric environments in which they must operate.  A real-time capability to accurately specify and forecast neutral atmosphere densities, which affect satellite drag, is under development to meet US Space Command satellite tracking, collision avoidance, and reentry prediction requirements.  The models will also have important application in satellite design, including lifetime predictions and on-board fuel requirements, and in the development of models for space-debris threat assessments.  Ionospheric research is focused on the development of reliable specification and forecast techniques and models, which are driven in near real-time with data from ground- and space-based sensors.  Included is the development of techniques to provide timely warnings of when, and how severely, ionospheric conditions and disturbances (solar related or man-made) will disrupt or even black-out C3I systems.  System operating parameters can then be appropriately adjusted, or alternate back-up systems can be deployed, to insure uninterrupted C3I operations.  In a related technology area, research is being conducted to characterize, control, and mitigate the disruptive effects produced on GPS-guidance, homing, and communication systems operating in the presence of intense ionization produced around very high speed aerospace platforms, such as the Military Spaceplane.

Description: (U)
(U) This focused technology area is comprised of three projects:  Ionospheric Impacts on Combat Operations; Chemistry Impacts on Military Space; and Precision Employment Technology.

(U) Ionospheric Impacts on Combat Operations:  Its objective is to develop global sensor-driven ionosphere specification and forecast techniques and models having errors less than 10% to specify preferred C3I-system operating frequencies and modulation schemes, and to greatly reduce surveillance tracking and range errors.  Develop the capability to globally specify and forecast neutral atmosphere density to within 5 percent over the 90-1600 km altitude range to meet DoD requirements for specifying satellite drag, and for application in models to reliably assess the long-term threat that space debris poses to DoD space systems and operations.

(U) Precision Employment Technology: Its objective is to develop advanced navigation analysis and technologies for precise positioning, guidance, targeting, pointing, and weapons delivery.  Develop positioning and targeting error analysis for hypervelocity vehicles.  Optimally integrate advanced GPS and inertial sensors is being developed for these applications and develop precise, jam-free, passive and non-emanating navigation and terrain avoidance systems for missiles and aircraft.  Apply inertial sensor technology to detecting and imaging of underground targets from moving-base platforms. 

(U) Ionospheric Scintillation Effects on C3I Systems: Its objective is to develop the capability for timely warning of impending outage conditions for communications, navigation and surveillance systems caused by disturbed regions in the ionosphere.  This requires understanding the basic physical processes that control the structure and dynamics of the ionosphere, and requires experimental measurements of the ionosphere and quantification of ionospheric effects on AF and DoD systems.

User Impact: (U)
(U) To be supplied.

Programmatics: (U)
(U) Concept/Technology.
	(U) IOC: 02/1996 (2QFY1996).

Related Initiatives: (U)
(U) None.

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) Battlespace Comms & Ops

Road Map Placements: (U)
(U) TECHNOLOGY- RDT&E.

Lead Office: (U)
(U) Air Force.

Date of Information: (U)
16 July 1997

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)