SBIR-STTR Award

Nuclear Scintillation Mitigation by Matched Channel Filtering
Award last edited on: 9/8/2022

Sponsored Program
SBIR
Awarding Agency
DOD : DTRA
Total Award Amount
$1,261,046
Award Phase
2
Solicitation Topic Code
DTRA202-005
Principal Investigator
Dennis Knepp

Company Information

Northwest Research Associates Inc (AKA: NWRA)

4118 148th Avenue NE
Redmond, WA 98052
   (425) 556-9055
   info@nwra.com
   www.nwra.com
Location: Multiple
Congr. District: 01
County: King

Phase I

Contract Number: HDTRA121P0005
Start Date: 3/10/2021    Completed: 10/9/2021
Phase I year
2021
Phase I Amount
$167,311
The ongoing development of new, improved technology for both hardware and software leads to the almost constant upgrade of existing strategic sensor and communications systems and the development and deployment of new systems. This work addresses warfighter concerns raised in the area of satellite communications and radar, where burst-produced ionospheric disturbances can cause scintillation of a propagating signal. The signal can experience fading of amplitude and phase, as well as rapid variation in time-of-arrival and angle-of-arrival. Without mitigation, these disturbances can cause increased error rate and degraded communications and sensor performance. All these propagation channel disturbances are mathematically described by the channel impulse response function (CIRF). The CIRF can vary in time for a particular propagation channel due to movement of the ionization or movement of the transmitter or receiver which causes motion of the propagation path with respect to the ionization. The objective of this work is to determine, in real time, the time-varying ionospheric transfer function (or channel filter) (the transfer function is the Fourier transform of the CIRF). In the proposed work, the transfer function is used to obtain the “matched channel filter (MCF).” The MCF can be applied to the received signal to precisely compensate for the effects of the disturbance. Determination of the MCF is thus a first step towards full mitigation of SATCOM link disturbances. Under this work, we will also investigate the accuracy of our processing to determine the MCF, develop and test methods to measure the channel parameters in real time, and perform a sensitivity study to determine channel parameter measurement accuracy.

Phase II

Contract Number: HDTRA222C0011
Start Date: 8/22/2022    Completed: 8/21/2024
Phase II year
2022
Phase II Amount
$1,093,735
The ongoing development of new, improved technology for both hardware and software leads to the almost constant upgrade of existing strategic sensor and communications systems and the development and deployment of new systems. This work addresses warfighter concerns raised in the area of satellite communications and radar, where burst-produced ionospheric disturbances can cause scintillation of a propagating signal. The signal can experience fading of amplitude and phase, as well as rapid variation in time-of-arrival and angle-of-arrival. Without mitigation, these disturbances can cause increased error rate and degraded communications and sensor performance. All these propagation channel disturbances are mathematically described by the channel impulse response function (CIRF). The CIRF can vary in time for a particular propagation channel due to movement of the ionization or movement of the transmitter or receiver which causes motion of the propagation path with respect to the ionization. The objective of this work is to determine, in real time, the time-varying ionospheric transfer function (or channel filter) (the transfer function is the Fourier transform of the CIRF). In the proposed work, the transfer function is used to obtain the “matched channel filter (MCF).” The MCF can be applied to the received signal to precisely compensate for the effects of the disturbance. Determination of the MCF is thus a first step towards full mitigation of SATCOM link disturbances. Under this work, we will continue to optimize and refine the MCF developed under Phase I and to transition the algorithms to operate in real-time using software radios.