SBIR-STTR Award

Forecast skills of ionospheric operational models are negatively affected by the complexity of the underlying physical system and the necessity to specify a number of poorly known parameters. Hence these forecast models, including the PRISM used by the Air Force, are usually empirical, rather than the first-principles models. In addition, until recently ionospheric research suffered from lack and sparsity of observational data. This situation is changing dramatically owing mostly to advances in remote sensing of the ionosphere from space. Availability of vast amounts of observational data together with advances in computing power make it possible for the first time to apply data assimilation techniques to first-principles ionospheric models for improved forecasting and modeling of the ionosphere and the upper atmosphere. The primary goal of this Phase I research proposal is to identify data assimilation methods most suitable for use with ionospheric models and to implement the prototype data assimilation and forecast system for spatial distribution and time evolution of the ionospheric electron density. In Phase I we plan to design and test the algorithms using the Coupled Thermosphere Ionosphere Model (CTIM). The developed data assimilation algorithms and codes would be applicable to any physics-based global ionospheric model. In Phase II of this effort we will interface the developed system with the Coupled Thermosphere Ionosphere Plasmasphere Model (CTIPM) and the coupled thermosphere and ionosphere model CITFM used by the Air Force and create the practical real-time forecast system. Anticipated improvements in model's forecasts of ionospheric electron density profiles will be of immediate use for a number of military and civilian practical applications, particularly in communications and navigation. The proposed Phase I work will determine the fundamental data assimilation techniques needed to develop a practical operational electron density forecast system during the Phase II effort. In the private sector potential clients include companies operating cellular phone and pager networks, navigation infrastructure, in particular GPS receivers, other satellite-based communications, such as satellite-based wireless Internet service providers, and power grid companies. Development of practically feasible ionospheric forecast system will address these needs and open up radically new commercial and military applications in the field of wireless communications.

Phase I results have clearly demonstrated the potential of the application of data assimilation techniques for modeling and forecasting of the electron densities in the ionosphere. The results show a significant reduction in the ionospheric forecast error even with a relatively modest number of simulated data samples assimilated into the Coupled Thermosphere Ionosphere Model (CTIM). In Phase II we will deliver a practical forecasting system based on the theoretical principals and prototype software modules developed and tested during Phase I investigation. The proposed product is paramount for enabling precise navigation, uninterrupted communications, high accuracy mapping, and remote surveillance. Following recommendations of the Air Force technical personnel, the system will be geared toward producing nested grid high-resolution real-time regional and local nowcasts and forecasts of electron density distributions. Generated distributions will be used to determine propagation conditions for different signal frequencies and converted to high-precision GPS coordinate corrections. The system will be initially implemented for high-latitude regions over the continental US. The unique ability to accurately forecast regional ionospheric conditions will allow the Air Force or civilian wireless connectivity providers to predict potential communication interferences and make proactive routing decisions or operate on different frequencies in response to the changing environment. The high-accuracy GPS corrections are superior in temporal and spatial resolution to those provided by the Wide Area Augmentation System or other differential GPS correction services resulting in precise location determination without the bulkiness, weight and cost of the dual-frequency GPS receivers. Other applications include over-the-horizon mapping by bouncing the radar beam off the ionosphere, high-precision altimetry and surveillance via accurate measurements of delays in satellite-based radar echoes, and improved determination of satellite orbital parameters. Additionally, ground-to-satellite data links at the UHF and SHF bands are subject to degradation caused by ionospheric scintillations. As broadband ground-to-satellite field communications, such as live video links, become more important, so will the ability to forecast the signal propagation conditions at these frequencies. Accurate determination of the ionospheric structure will provide future capabilities for determining plasma irregularities formation. A major component of the proposed system is the ability to optimize placement of new space- or ground-based sensors providing operational data. This will be achieved via running multiple virtual scenarios and single value decomposition analysis. This ability, arising from high computational efficiency and small footprint of the system, will provide huge cost savings in planning future field missions, particularly when space-based instruments are concerned, and will further improve the quality of the forecast.

Benefits:
Our product has applications in most areas of military operations, from HF communications to delivering vital data to individual soldiers in remote battlefields, to precision guided weapons, to space based intelligence gathering and estimating satellite charging. Many existing military operations will see immediate benefits, e.g., better position determination with GPS receivers and efficient HF communications. The unique ability to forecast regional ionospheric conditions will allow the military connectivity providers to predict potential communications interferences and make proactive routing decisions or operate on different frequencies in response to the changing environment. While several DoD agencies will benefit from using the proposed technology, the US Air Force will likely see the biggest immediate cost-savings resulting from a better ability to communicate and large cost reductions from the new ability to optimize geometry of planned space observational missions. Target commercial applications of our product include HF FAA communications, remote voice and data services, precise mapping, E-911 services, intelligent automated vehicles (terrestrial and airborne), goods and supplies distribution management, and modern agriculture.