Designing Wireless Sensor Solutions for Tactical ISR

Current events have demonstrated a need for effective & persistent monitoring of secure areas, structures, and/or assets. But how, and with what approach? Significant advances have availed themselves regarding the design & development of capable Wireless Sensor Network (WSN) systems via the recent confluence of relevant technologies. WSN, a specialized subset of the Internet of Things (IoT), has repeatedly demonstrated outstanding capability & versatility in achieving autonomous & cost-effective remote sensing. Through ever-evolving WSN systems, more and more endeavors associated with data acquisition and observations can be deployed worldwide without observers or control centers in proximity.

Using WSN, both military & non-military surveillance, reconnaissance, and target tracking have reached impressive levels of measurement granularity. With the availability of a dense sensor fabric through WSN systems, highly-defined mining of valuable data has been achieved by those involved in threat assessment, force projection analyses, as well as surveillance of areas of interest (AOI). For the military, WSN represents a viable approach to distributed persistent sensing anywhere in the world.  For commercial ventures, WSN systems have been, and continue to be, successfully implemented to conduct cost-effective worldwide tracking and/or assessment of various items and/or properties.

The course is based on the text, Designing Wireless Sensor Solutions for Tactical ISR [Artech House publishing, 2020]. Similar to the text, the course is structured using a “system engineer (SE) perspective -- think system design, product realization, and technical management processes (ref. NASA System Engineering Handbook SP-2016-6105 Rev2, INCOSE Systems Engineering Handbook, 5th Edition).  This course addresses sensor node design, system development processes, WSN node subsystems, and methodologies to model, evaluate, predict system performance, conceptual design phase -to- operating system product (a-to-W) process. Topics are introduced, equations derived, and actual implementations presented to define:

• Processes behind defining & revising mission objectives
• Derivation of responsive system requirements
• Physical characteristics involved (e.g., RF propagation, sensor principles)
• Reviewing mathematical approaches to RF, sensor, & system performance modeling
• WSN node subsystem design & hardware solutions
• Signal sampling & data processing review & implementations
• Approach to real-time network management system
• Middleware development & use of machine learning (ML), SOA, & use of SWE capabilities
• System-level verification & validation (V&V) tracking & process
• History behind, lessons learned, & presentation of existing WSN-based systems  

 Click this link to view a short course overview

• Those working on designs, development of remote sensing systems
• Designers or users of WSN technologies
• Remote sensor engineers & scientists
• Engineers, managers, stakeholders involved with tactical ISR
• Military field-operatives involved in T-ISR
• Non-military designers & users of remote sensing systems for application to surveillance and/or tracking of property

• The course has been decomposed into 12 individual modules.

   Preface T-ISR Systems Course

  • Course preview
  • Presentation of general terms & definitions associated with course materials

   ISR, System Design, & Critical Technological Developments

  • History of T-ISR systems effectiveness & lesson learned from previous systems are provided.
  • ISR is presented at the top-level
  • Tactical ISR objectives differentiated from ISR realm
  • ISR (T-ISR) objectives and how to evaluate overall system effectiveness?
  • What are the system products for T-ISR?
  1.  WSN-based T-ISR Systems
  • T-ISR sensor systems and issues experience
  • How did the emergence of WSN as a viable solution come about? And lessons learned?
  • WSN nodes (motes) functional diagram & technologies used to realize such
  • Future casting for WSN -- strides that impact WSN designs
  • Technical Readiness Level (TRL) definition and application: assessing appropriateness (and risk) of injecting novel technologies into a design
  • Multi-tiered sensor architecture

   

  1.  Probabilistic Modeling
  • Review of probability theory pertinent to describing detections, false alarms, and messaging traffic
  • With probability & statistical inference, can we develop performance models?
  • Gaussian & Poisson noise characterization
  • Active (laser & RF radar) sensor modeling, it differs from those using passive sensing!

   

  1.  WSN RF Propagation Characteristics
  • Review of wireless networking design, from perspective of physical (PHY) & media access control (MAC) perspectives
  • How do WSN propagation effects differ from other RF systems?
  • PHY aspects described in detail via propagation models
  • WSN requirements summary
  • Derivation of link equations for multiple received-power model (Rayleigh, Rician, TWP)
  • Fading models
  • What is we have moving nodes? Mobility-induced frequency shift model
  • Final considerations concerning LP wireless communication links

   

  1.  Sensor Modalities
  • Prevalent sensor (node) modalities: optical (passive & active), RF/ultra-wideband (UWB), acoustic, magnetic, seismic, and chemical-biological devices
  • How do the WSN sensor modalities behave?
  1. Sensor characteristics
     1. Derivation of sensor modality performance equations
  • Target & background characteristics
  • Specialized sensors:
  1. Laser vibrometry sensors (LVS)
  2. Ultra-wideband RF radars, are presented
  • Actual WSN node sensor designs and devices

   

  1.  Hardware Subsystems
  • Overview of WSN node subsystem hardware
  • WSN node examples history & examples
  • Sensor node subsystems descriptions & examples
  1. Micro-computer (uC) systems reviewed
  2. Sampling theory overview
  3. Analog-to-digital converters (ADCs)
  4. Characteristics of low power (LP) ISM transceivers
  5. Survey of LP GPS receivers
  6. Node-based secondary sensor discussed
  • Various node input/out (I/O) approaches
  • How do we connect a WSN motefield to the world?
  1. Discussion of control & data exfiltration relays, the “what” that bridges sensor field to the world
  2. Prevalent worldwide communication infrastructures (e.g., DoDIN)

   

  1. Middleware & Software
  • Intro to thin real-time operating systems (RTOS) systems
  • Middleware:  which flavor?
  1. Data-centric
  2. Network-focused
  • Target detection
  • Sensor cueing is described
  • Sensor-to-sensor correlation processing
  • Target tracking algorithms
  • Data aggregation
  • Target discrimination & identification  

   

  1.  Network Management System (NMS)
  • Network management system (NMS) control overview
  • Network formation & maintenance (e.g., self-healing).
  • Use of Jain Fairness Index
  • Which of the routing or MAC protocols to use?
  1. Various routing algorithms (e.g., DSDV, OLSR, WRP, CCS/LCC protocols)
  2. Media access control (MAC) for WSN.
  • Link characterization
  • Examples of NMS implementations

   

  1. 10.  Network Security Issues
  • Insight to WSN communication security schemes
  • Overall security goals pertinent to WSN systems
  • Various attack to be concerned over
  • And a few countermeasures

   

  11. WSN Systems Engineering (SE)

  • Using “System Engineering perspective” in WSN design & development?
  1. Embrace of DoDAF/UPDM
  2. Flow-down process for top-level requirements
  • Activities associated with verification & validation (V&V)
  • Design process of baseline system described
  • System functional block & N2 diagramming
  • Mission operation center (MOC) data acquisition & exfiltration of data,
  • Seamless integration – how to account for legacy systems & processes?
  1. Situational awareness (SA) processing
  2. Integration with MOC operations & processing center
  3. Common operating picture (COP) constructs
  • Employing System-Oriented Architecture (SOA)
  • Aiding sensor integration via system web enablement (SWE)

   

  1. 12.  System Deployment & Operation
  • Initialization of WSN systems
  • Deployment mechanisms
  • Power management
  • Operation of WSN-based system
  • How are test data obtained?
  • How well did various WSN systems performed?

   

• System-view of a remote sensing capability from mission objectives -to- final deployment & operation
• Thorough exposure to tactical ISR requirements & system functionality
• Working knowledge to perform evaluation of sensor modalities & LP RF links
• Derivation of mathematical constructs used in establishing sensor & RF performance
• Understanding of core detection & false alarm/noise characteristics
• How & which packetized network protocols work well with low-power, low-cost (LPLC) mesh networks
• What onboard functions are required by a node, as well as a WSN system
• What is meant by data aggregation
• What routing protocols have been successful
• Onboard (sensor node) processing requirements to maintain data volume & reliability through the system
• An understanding of unique challenges for wireless data communication at/near ground level
• Defining and/or deriving T-ISR data production and dissemination characteristics
• Approaches to system V&V
• How to account for seamless integration within legacy systems.
• An understanding of various ad hoc network MAC protocols, which work & which not-so-much
• Geospatial localization issues & solutions for randomly distributed sensor nodes
• What middleware-based functions are required
• Sensor node deployment schemes
• Lessons learned from history remote sensing applicable to current system requirements

Case studies of WSN embedded into T-ISR systems

Timothy Cole has 4 decades and has over 30 publications & textbooks from involvement & direct experience involving design, development, and operation of EO/IR instrumentation and attendant systems. His career “hats” include: engineering positions (system engineer, field testing), principal investigator (PI), science team member (NASA NEAR & ICESat-2 missions), and technical/line manager. During his 24 years at The Johns Hopkins University/Applied Physics Laboratory (JHU/APL), Mr. Cole developed models & simulations to evaluate performance of strategic submarine inertial systems (USN SSBNs); designed and developed the US Navy’s Geosat-1 TT&C ground station (and Ku-band altimetry data processing); worked on Cosmic Background Explorer  (COBE) ground station, demonstrated laser radar approach to perform US Navy’s non-cooperative target identification (NCID) for over-the-horizon targeting (OTH-T) applications; and designed & developed NASA’s Near-Earth Rendezvous Laser Radar (NLR) instrument. With APL & JHU Wilmer Eye Institute, he developed & tested a photorefractor instrument designed to acquire optical characteristics of preverbal patients. With the University of Mississippi, he demonstrated use of to provide remote sensing by laser radar to detect minefields. At Teledyne-Brown Engineering, Mr. Cole led science & engineering teams to develop & evaluate exoatmospheric sensors & long-wave IR (LWIR) detector capabilities for Space & Missile Defense (USBMDSCOM, Huntsville). He was involved in improving the BMD Optical Signatures Codes, various tracking models, and designed a sensor wavelength optimization tool for BMD.  As chief engineer for Northrup Grumman (NG), he led the NG/Tampa engineering department under the auspices of DARPA’s seed program, the Networked Embedded Systems Technology (NEST) program. The NEST effort involved design, evaluation, & field-testing of WSN-based systems for DARPA & DIA. While working with NASA/GSFC, Mr. Cole was appointed the instrument systems engineer (ISE) & subsequently, as part of science team, lead calibration manager for NASA/GSFC’s ICESat-2 laser altimeter (ATLAS). Mr. Cole holds degrees in electrical engineering and technical management. He has been recognized by receiving 2002 NASA Achievement Award with NEAR laser altimeter team, being awarded 1998 NASA Group Achievement Award. While at Northrop Grumman, Mr. Cole was nominated to and held the position of Technical Fellow, during which time, he provided scientific & engineering inputs across NG divisions.