Multiple radar environment emission deinterleaving and PRI prediction

The aim of this study was to research TOA based tracking and deinterleaving algorithms suited to radar emitters in an EW environment for application on the CSIR 5th generation DRFM platform. The research problem statement stipulated that the only defining characteristic of the different emitters be the time of arrival (TOA) of their pulses. The pulse repetition interval (PRI) schemes considered in the study was constant, jittered, staggered and dwell and switch. The different TOA based deinterleaving algorithms investigated were sequence search (SS), TOA difference histogram, CDIF, SDIF, CDIF with SS (CDIF SS), SDIF with SS (SDIF SS) and interleaved pulse train spectrum estimation. The interleaved pulse train spectrum estimation algorithm results could not be replicated and were not included in simulations. The TOA based tracking algorithms that were also investigated were Delta-t histogram, Kalman filter, alpha-beta filter and alpha-beta-gamma filter. The alpha-beta-gamma filter became unstable during simulations and hence their results have also been excluded. The algorithms were simulated in MATLAB against EW environments with varied TOA measurement noise, number of emitters, PRI schemes and interference pulses (missing and spurious). General conclusions drawn from the deinterleaving simulations were the success of the algorithms decrease with the increase of emitters in the EW environment, interference pulses increased the success of some algorithms and the success of algorithms increased with TMNR (time measurement to noise ratio). General conclusions drawn from the tracking simulations were track loss of the algorithms decrease with increase in TMNR, tracking error decreases with increase in TMNR and interference pulses affected the initial estimates used to initialise the filters. The performance of the deinterleaving (CDIF & CDIF SS) and tracking ( Delta-t histogram & alpha-beta filter) algorithms were compared on the DRFM platform. On the DRFM platform, the CDIF algorithm deinterleaved in fewer pulses but had more false detections as compared to the CDIF SS algorithm. The alpha-beta filter performed better with lower TMNR than the Delta-t histogram, on the DRFM platform. The CDIF SS algorithm and alpha-beta filter were chosen, based on their performance on the DRFM, to be implemented on a DRFM based system that would deinterleave and then track emitters in an EW environment. The system was successfully implemented and met all requirements that were placed on it. Possible improvements to the system and the future improvements to the research are also discussed

The applications of satellites to communications, navigation and surveillance for aircraft operating over the contiguous United States. Volume 1 - Technical report

Satellite applications to aircraft communications, navigation, and surveillance over US including synthesized satellite network and aircraft equipment for air traffic contro

Viking '75 spacecraft design and test summary. Volume 1: Lander design

The Viking Mars program is summarized. The design of the Viking lander spacecraft is described

Remote Sensing

This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas

NASA Tech Briefs, January 1991

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences;Life Sciences

The Telecommunications and Data Acquisition Report

Reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other agencies through NASA

Fall Detection Using Channel State Information from WiFi Devices

Falls among the independently living elderly population are a major public health worry, leading to injuries, loss of confidence to live independently and even to death. Each year, one in three people aged 65 and older falls and one in five of them suffers fatal or non fatal injuries. Therefore, detecting a fall early and alerting caregivers can potentially save lives and increase the standard of living. Existing solutions, e.g. push-button, wearables, cameras, radar, pressure and vibration sensors, have limited public adoption either due to the requirement for wearing the device at all times or installing specialized and expensive infrastructure. In this thesis, a device-free, low cost indoor fall detection system using commodity WiFi devices is presented. The system uses physical layer Channel State Information (CSI) to detect falls. Commercial WiFi hardware is cheap and ubiquitous and CSI provides a wealth of information which helps in maintaining good fall detection accuracy even in challenging environments. The goals of the research in this thesis are the design, implementation and experimentation of a device-free fall detection system using CSI extracted from commercial WiFi devices. To achieve these objectives, the following contributions are made herein. A novel time domain human presence detection scheme is developed as a precursor to detecting falls. As the next contribution, a novel fall detection system is designed and developed. Finally, two main enhancements to the fall detection system are proposed to improve the resilience to changes in operating environment. Experiments were performed to validate system performance in diverse environments. It can be argued that through collection of real world CSI traces, understanding the behavior of CSI during human motion, the development of a signal processing tool-set to facilitate the recognition of falls and validation of the system using real world experiments significantly advances the state of the art by providing a more robust fall detection scheme

Research & Technology Report Goddard Space Flight Center

The main theme of this edition of the annual Research and Technology Report is Mission Operations and Data Systems. Shifting from centralized to distributed mission operations, and from human interactive operations to highly automated operations is reported. The following aspects are addressed: Mission planning and operations; TDRSS, Positioning Systems, and orbit determination; hardware and software associated with Ground System and Networks; data processing and analysis; and World Wide Web. Flight projects are described along with the achievements in space sciences and earth sciences. Spacecraft subsystems, cryogenic developments, and new tools and capabilities are also discussed