Model-Based Design for a Netted ISR Concept Model-Based Design for Affordability of a Netted Intelligence, Surveillance, and Reconnaissance Concept K. Dewayne Brown, Mary Beth A. Chipkevich, Robert J. Bamberger, Tam-Thanh C. Huang, Mark A. Matties, James D. Reeves, and Christopher A. Rouff ABSTRACT This article highlights the critical importance of systems engineering methodology and its influence on downstream outcomes in complex engineering concepts. It makes a development case for complex systems of systems that contrasts netted with traditional intelligence, surveillance, and reconnaissance. Model-based systems engineering methods supported by development infrastructure can significantly impact the life-cycle affordability of complex systems of systems. The long-standing systems engineering practices of the Johns Hopkins University Applied Physics Laboratory (APL), the International Council on Systems Engineering, and the Open Group Future Airborne Capability Environment Consortium, as well as the objectives for projects such as the Defense Advanced Research Projects Agency Air Dominance Initiative, provide context for an APL brand of model-based methods. This article introduces an APL model-based systems engineering methodology within an integrated development environment and discusses the methodology in the context of a netted intelligence, surveillance, and reconnaissance concept. INTRODUCTION BACKGROUND More than 70% of program life-cycle costs are determined in the concept engineering phases. A modelbased systems engineering (MBSE) methodology, integrated development environment (IDE), and systems engineering (SE) infrastructure provide engineers the capability to cost-effectively explore, model, prototype, and validate concepts. A case study for intelligence, surveillance, and reconnaissance (ISR) concept engineering piloted use of this capability, and it was determined that one concept was more affordable (in terms of lifecycle costs) and rapidly realizable (in terms of development time lines) than an alternative concept. The overall complexity of national security and operational warfare is increasing.1 Complexity of the systems of systems (SoS) needed to deliver mission capability is also increasing, particularly with regard to the amount of information exchanged, the degree of interaction among battle force units, and the battlespace environment.2 Concurrently, DoD budgets are trending downward.1 Affordability is the new number one threat to developing, delivering, integrating, and sustaining needed capabilities.3 The DoD has recognized the need to reduce life-cycle costs early in the development of concepts and capabilities, as evidenced by various studies and initiatives (see Fig. 1). Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 23­­­­ K. D. Brown et al. The Reality... “Our current security challenges are more formidable and complex than those we faced in downturns following Korea, Vietnam, and the Cold War. There is no foreseeable ‘peace dividend’ on our horizon.” —GEN DEMPSEY, CJCS Testimony to SASC, 12 Feb 2013 $800 Korea Vietnam OEF/OIF Reagan Buildup/ Cold War $700 $500 $400 1996 2020 2017 2014 2011 2008 2005 2002 1999 1996 1993 1990 1987 65-year Average = $477B 1984 1978 1975 1972 1969 1966 1957 1954 1948 $0 1951 $100 1963 Actual 65-year Avg. PB13 Projection Sequestration Projection Historical Trough Projection $200 1981 $300 1960 CY13 $ in B $600 Figure 1. Battlespace complexity and affordability. [Right image from G. Boltz (APL) and left from Ref. 1.] MOTIVATION Applying SE practices provides necessary structure throughout the life cycle of a system. Supporting modelbased infrastructure enables effective management of performance, schedule, and cost over significant portions of the concept-development life cycle, including exploration, verification, and validation. Models facilitate efficient expression of system requirements, structure, behavior, and function along with rapid communication, distribution, and functional decomposition of complex systems. Model-based methods enable effective, rapid, and low-cost decisions to be made among alternatives when engineering a complex SoS. In this case study, application of a model-based methodology demonstrates the ability of these methods to significantly impact the life-cycle affordability of ISR concepts. Figure 2. A maritime interdiction scenario. 24­­­­ Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept Figure 3. Anti-access/area-denial maritime dynamic targeting scenario. THE ISR CASE: THE CHALLENGE Warfighters need a capability to command and operate an ISR SoS more effectively and affordably than they can today. Tasking–collection–processing–exploitation– dissemination (TCPED) is a process that uses an SoS during military operations to achieve ISR mission objectives determined by commander’s intent. The tasking– collection (TC) portion of TCPED encompasses actions and decisions related to planning for, tasking of, and operation of systems that contribute to ISR mission objectives. The increasing number and diversity of ISR assets as well as competing ISR mission requirements challenge the effectiveness of existing doctrine, processes, and systems to command and manage the use of ISR platforms and sensors.4, 5 The volume and multiple modalities of sensor data can overwhelm the processing– exploitation–dissemination (PED) portion of TCPED.5 “As-is” traditional ISR SoS TCPED processes have time-consuming and manpower-intensive TC and PED activities and require high-bandwidth reachback communications. As-is TC requires mission control operators at ground control stations or on manned airborne, surface, or subsurface platforms to perform sensor control and platform control of assigned “stovepiped” ISR assets in a reactive rather than a predictive manner. This reduces time available to properly respond to a situation and suboptimizes overall ISR SoS performance. As-is PED involves transfer of raw sensor data via reachback communications to intelligence community facilities. Analysts use available systems at these locations to process, exploit, and disseminate fused intelligence products for use by command-and-control decision makers. In dense battlespace environments and with increasingly complex SoSs, synchronization among nodes in the SoSs operated by naval, joint, and coalition forces requires timely and tight coupling with operations, targeting, and intelligence operational doctrine to deliver the ISR targeting information necessary to support weapons planning.5, 6 This is particularly true for dynamic targeting scenarios. As-is TCPED with traditional ISR SoSs does not provide the required timely coordination and reporting between operational processes and nodes/ capabilities.2, 4, 5 Figures 2 and 3 show notional scenarios for maritime interdiction and anti-access/area-denial maritime dynamic targeting, which provide operational context with communications, threat detection tracking, classification, and other challenges for the netted ISR concept. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 25­­­­ K. D. Brown et al. THE ISR CASE: NETTED ISR CONCEPT The concept of a “to-be” TCPED-centric netted ISR SoS is an alternative to the present as-is ISR architecture. A TCPED-centric netted ISR SoS enables the warfighter to command a collaborative sensor fusion capability and optimally, reliably, and locally control actions and decisions for each node; it also increases the ability of the SoS accomplish missions and tasks. Data fusion (e.g., PED), previously completed in central locations, now occurs on sensor platforms. It uses organic and remote sensor data, increasing resiliency in degraded communications environments. Data fusion also occurs at data fusion centers specified by the commander. Constellation-wide sensor resource allocation (e.g., TC) occurs on both platforms and among operational commands designated by the commander to optimize data collection. The output of data fusion is fed back nearly instantaneously as input to sensor fusion. The netted ISR concept is enabled by end-to-end connectivity with quality of service that allows in-degree nodes of the SoS to assuredly share relevant information. With netted ISR, command, sensor fusion, and data fusion capability is allocated to functional elements on segments that distribute across physical nodes in the SoS. Segments are a collection of functional elements. The expected role of each node determines the extent to which each segment is instantiated on the node. The designated role of each node for a specific operational mission determines the extent to which the instantiated segments are used on each node. As such, the netted ISR concept is extensible to platforms with varying space, weight, and power constraints; scalable to a very large number of connected nodes; and adaptable to a range of collaborative behaviors (e.g., nodes behaving as individual contributors, as neighbors, as a community, or with a swarm identity). Functional elements of command include the ability to collaborate, translate the commander’s intent into measures allocated to tasks and objectives, assess the performance of the SoS and infer achievement of the commander’s intent, decide the priority of mission requirements to achieve the commander’s intent, and assign mission requirements to ISR assets. Functional elements of sensor fusion include the ability to infer sensor collection needs, decide and task sensor data collections and platform movement, skew sensors, move sensor platforms, collect sensor data, and share sensor data. Functional elements of data fusion include the ability to receive and prepare sensor data for processing; screen sensor data; share relevant sensor data; perform processing to detect objects, track hostiles, precisely track hostiles, track all objects, classify targets, and determine intent of targets; develop object/target reports; share object/target reports; and maintain an ISR data repository. 26­­­­ Implementation of data fusion includes data conditioners, screening components specialized to multiintelligence and multi-modality sensors, fusion components that perform data association, kinematics state estimation, class estimation, and data association. The data fusion approach exploits complementary attributes of diverse sensor phenomenology/geometries and data collected over time to maintain a low system-level, post-correlation false-alarm rate. Output conditioning prepares and disseminates fusion output (e.g., actionable information, target reports, and target nomination reports) at achievable data transmission rates.7 Implementing sensor fusion will include automated components that coordinate and synchronize ISR sensor platforms as an integrated unit to continuously maximize aggregate net fused information gain and adjudicate tasking among competing priorities across the entire search volume and all targets, as well as over a configurable finite planning time horizon.8 Implementing command of a netted ISR SoS will involve automation that shifts much knowledge and inference functionality performed by operators in the cognitive domain to processors in the logical domain. Collaborative cognition will occur between warfighters and the command capability of the netted ISR SoS. The netted ISR command functional element will provide the capability to reliably optimize responses to emergent behaviors associated with SoS complexity;9 relate those responses to commander’s intent, battlespace complexity, cognitive parameters, and decision policies established in doctrine; and synchronize the information, social, cognitive, and physical domains of battlespace management command and control.10 The concept of netted ISR and its collaborative command, sensor fusion, and data fusion capability aligns well with the Navy Information Dominance Roadmap, which states, “Battlespace Awareness will require enhanced information content, advanced means to rapidly sense, collect, process, analyze, evaluate and exploit intelligence regarding our adversaries and the operating environment.”11 Netted ISR Reference Architecture To facilitate SE of the netted ISR concept, a reference architecture was developed, as depicted in Fig. 4. The reference architecture is intended to guide and frame architecture and solution development. There are sensor, command, and fusion segments, which are instantiated on nodes that distribute across an SoS and interconnect by a heterogeneous network. All node types have a multiprocessing hardware architecture. The processors can be subdivided into non-realtime and near-real-time types. Software that is event driven, such as user/mission applications and higher-level networking services (application, presentation, session, Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept Sensor subsystem Sensor 1 Sensor N Sensor manager Platform manager Platform control subsystem Local sensor data fusion applications Command applications Local sensor fusion Local core services Network services Communications services Task sensors Task weapons Task platforms Decide Infer Translate intent Network services Communications services Local core services Hardware Hardware Sense segment ∑im (m = 1, 2,..., M) Heterogeneous network Command segment ∑in (n = 1, 2,..., N) ISR fusion applications Sensor data fusion ISR repository Local core services Sensor fusion Common operating picture Network services Communications services Hardware Fusion segment ∑ip (p = 1, 2,..., P) Figure 4. Netted ISR reference architecture. transport, and network OSI [Open System Interconnection] layers), are hosted on the non-real-time processors, such as general-purpose processors and/or graphic processor units. The software architecture can be partitioned into two broad groups. Software that is near real time, such as lower-layer networking services (data and physical OSI layers), is hosted on near-real-time processors, such as digital signal processors or field-programmable gate arrays. The software architecture can be partitioned into user/mission applications and services such as local core, networking, and communication. The local core, networking, and communication services enable applications to execute the mission and interact with any node distributed in the SoS and across all segments of the SoS. User/mission applications are specific to each type of segment. For instance, sensor segments host sensor interfaces, whereas the command segment hosts user interfaces and fusion segments host data-repository interfaces. This reference architecture is modular and scalable, which facilitates rapid integration of innovative technology, legacy design reuse, and interoperability between diverse functional platforms and heterogeneous networks. Case Study Approach: Netted ISR Model-Based Design for Affordability With the ISR challenge defined, operational context provided, and initial netted ISR concept and reference architecture developed, the SE challenge is to validate that the netted ISR concept can realize the needed ISR capability more affordably and rapidly than the traditional ISR of today. Resource constraints on the MBSE methodology development were a 4-month schedule and eight parttime subject-matter experts. The study team focused on design for affordability of the netted ISR concept and performed one innovation cycle using the MBSE methodology and SE infrastructure. The approach included modeling and analysis of ISR performance for an operationally relevant scenario as well as rapid development of an ISR network model, which enabled efficient exploration of both the traditional and netted ISR concepts. The network model was central to rapidly establishing ISR prototypes of both the traditional and netted concepts. Preliminary verification tests demonstrated performance of the ISR concepts. A cost model was developed and used to assess the affordability of both concepts. Results of Netted ISR Case Study Results from one innovation cycle of the concept engineering phase showed that the netted ISR concept directly improved the affordability and effectiveness of ISR. Preliminary verification tests for one scenario demonstrated that the netted ISR concept required 30% fewer sensor platforms and at least 25% fewer operators than the traditional ISR model. Netted ISR can reduce operational costs and reduce the number of assets needed to perform ISR. Cost modeling and affordability analysis showed significant, compounded life-cycle savings with the netted ISR concept compared to the traditional concept, especially as the battlespace becomes more complex. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 27­­­­ K. D. Brown et al. Mission/operational architecture and capabilities Solution (systems and services) architecture and functionality Solution validation Integrated System Model ta duc it rch ect ign des nd a ure This case study made use of an MBSE methodology, IDE, and SE infrastructure to design for affordability as part of a 4-month concept engineering phase of a complex SoS. The remainder of this article describes the Johns Hopkins University Applied Physics Laboratory (APL) MBSE methodology, IDE, and SE infrastructure used for this case study and its relevance to supporting and influencing SE over the life cycle of a system. on Pro Figure 5. APL SE process. (Reprinted from Ref. 12.) Detailed design Integration, test, and verification Implementation Figure 6. INCOSE MBSE methodology. HW/SW, hardware/software. (Reprinted from Ref. 13.) APL SE Process Implementation of the netted ISR architecture requires an effective balance of scientific and engineering principles, performance, requirements, and sponsor program constraints. This is a classical SE challenge. The APL SE loop,12 which has matured over decades, is shown in Fig. 5, and the major phases used to solve national and international critical SE challenges are described in Table 1. Every step produces knowledge and experience, which is fed back into subsequent spirals. The APL SE process is mature and proven and has informed the development of the APL MBSE IDE. Table 1. APL SE Process 28­­­­ Mission/operational Operation and architecture views maintenance Systems and services architecture views Systems engineering Requirements views System and HW/SW verification and views architecture validation Concept of operations tion xplora Concept e gra ti Systems Engineering Capability integration inte Critical needs Capability assessment Capability architecture Solution implementation and nt Pro duc t te st yme Deplo Process Step Description Critical needs Operational/mission data analysis is conducted, focused on establishing concept feasibility and exposing critical needs. Capability assessment Existing systems are evaluated to determine whether they can meet the need or whether a new capability development is required. Concept exploration Alternative candidate concept designs, models, and analyses are completed. Trade analysis enables effective down-selection to a best concept based on any number of metrics, such as performance, efficiency, economy, risk, utility, or a combination of these characteristics. Validation Proof-of-concept (PoC) prototypes are developed to verify functional performance in a representative environment. Implementation The concept is realized in an operational prototype, and verification tests are completed. Deployment The concept is deployed for field test validation. INCOSE MBSE MBSE provides a methodology to more effectively manage the SE challenge at lower cost and shorter development cycles. The International Council on Systems Engineering (INCOSE) has developed an MBSE methodology,13 which is shown in Fig. 6. This diagram highlights how models are central to this methodology. The Integrated System Model is a repository for all knowledge about the system (aiding in communication and collaboration). Capability and product architectures, along with design, verification, and validation testing, are derived from the Integrated System Model. This results in consistency, which improves maintainability and reduces ambiguity. Requirements traceability Government partners IDE MBSE methodology Development Framework Development framework Development tool set Project repository Reference architecture Commercial partners Figure 7. Integrated development environment. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept Sponsor challenge System PoC prototyping MBSE IDE Reference architecture Concept exploration: M&S Validated concept HW/SW prototyping System concept verification System concept implementation Development tools System concept validation IDE framework System M&S concept exploration IDE backplane V&V tools Figure 8. APL MBSE methodology. M&S, modeling and simulation. to architecture and associated design elements enables change impact analysis. Documentation is generated from the Integrated System Model, ensuring accuracy. Automatic code-generation processes ensure efficient implementation and quality management. Because the INCOSE MBSE developments are embraced by a broad range of SE organizations, the INCOSE model has informed the APL MBSE IDE development. MBSE IDE APL is maturing an MBSE IDE that enables distributed stakeholders to collaboratively contribute solutions to the SE challenge. The APL SE IDE is initially provisioned and targeted for the concept exploration, implementation, validation, and deployment SE processes. It is relevant for application by projects such as the Defense Advanced Research Projects Agency-sponsored Air Dominance Initiative project,14 whose objective was to integrate its Strategic Technologies Office capabilities for communications in a contested environment. The goals of the Air Dominance Initiative project included integration of legacy and future airborne communication waveProvides a rich system design and analysis environment Design flows provide machinegenerated code Concept system Machinemodeling and generated simulation code (blade servers) Test results feedback to system concept Provides a scalable collection of reconfigurable multiprocessor architectures Reconfigurable Prototype processing hard- models ware prototypes to industry (SDR 4000) V&V testing/field demonstrations (programmable test equipment) Industry product implementation Provides a rich collection of programmable test vectors and measurements Repository Figure 10. APL IDE framework. HW/SW, hardware/software. forms through heterogeneous networking protocols across increasing numbers of pervasive airborne nodes while achieving drastically reduced innovation cycles. The APL IDE as shown in Fig. 7 facilitates distributed collaboration on shared centralized resources among government sponsors, users, and technical leadership with commercial hardware, software, and service providers. It is based on an integration of MBSE methodology, a distributed integration framework, hardware and software reference architectures, development toolsets, and a repository. AN APL-Branded MBSE Methodology An APL-branded MBSE methodology (APL has developed a unique collection of processes, methods, and tools) is shown in Figs. 8 and 9. The major iterative and collaborative processes include (i) concept exploration through modeling and simulation, (ii) rapid prototyping through code generation, (iii) verification and validation (V&V) testing, and (iv) submission to the project repository. An inner closed loop enables rapid verification of concepts developed in the low-cost-of-change (relative Reference HW/SW architectures/ design kits Concept exploration tools Application, network, and communication services development tools Process capabilities feedback to system concept Figure 9. APL MBSE methodology flow. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Concept V&V tools Repository tools IDE framework Figure 11. APL IDE notional user interface. 29­­­­ K. D. Brown et al. to cost of change in physical hardware and software) modeling and simulation environment and influenced by lessons learned from V&V testing. The outer closed loop enables stakeholders to influence the concept development through disciplined design for X (where X is a variable for affordability, six-sigma, testing, manufacturing, and so forth). Netted ISR master reference architecture Software computing architecture Portable components segment (applications) VM Sensing applications Fusion applications Sensor 1 Sensor 2 Sensor N Process 1 Process 2 Process N Platform-specific services segment (local core services) Platform common services Config Logging Platform device services App 1 App N App 2 Transport services segment (network/communications services) VM Distribution (Dist) capabilities WF functions Dist Virtual machine (VM) GPS Data-processing applications WF fcn transport QoS Interworking fcn Config Secured Red data service routing Red QoS IDE Framework The SE IDE framework shown in Fig. 10 illustrates how hardware and software reference architectures, development, V&V tools, and a repository can be integrated. This integration facilitates transfer of information, availability of resources, and maturation of concepts. Shown in Fig. 11 is a notional framework interface that enables distributed developers to navigate, access, and process using shared IDE resources for concept exploration, implementation, verification, and validation. Within the IDE, integrated tools are able to interoperate across a common backplane. Future tool versions will be provisioned with plug-and-play interfaces, common reference architecture templates, and repository libraries. VM Input/output services segment (networking services) Addressing services Power control Mobility management Black routing Neighbor discovery Black QoS Flow control Operating system (OS) segment OS kernel Partitioning File system Hypervisor Hardware architecture Digital hardware Waveform processor Device driver Device driver Application/ networking processor Switch fabric Backplane switching Analog hardware Link-16 TTNT MADL CDL Future Figure 12. APL master reference architecture. CDL, common data link; Config, configuration; DNS, domain name service; fcn, function; MADL, multifunction advanced data link; QoS, quality of service; WF, web file. Hardware and Software Reference Architecture Within the SE IDE is a hardware and software master reference architecture, as shown in Fig. 12; it is based on the Technical Standard for Future Airborne Capability Environment (FACE)15 and provides functional and interface definitions for the hardware and software to be implemented. It illustrates the major software application, networking, and communication services as well as the major non-real-time and near-real-time hardware processor types. Incremental implementation of this ref- 30­­­­ DNS/subnet formation erence architecture is planned for several APL projects over the next few years. Concept Exploration The SE IDE includes modeling and simulation toolsets that enable concept exploration through PoC modeling and simulation. These concept virtual prototypes (VPs) enable exploration of a range of alternative approaches, analyzing the performance, costs, and benefits of each approach in an agile and low-cost-of-change environment. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept Pulse n: 256 encoded bits + 24 bits (S1) + 24 bits (S2) + 105 bits (NTmin) + max 512 bits (corresponding to largest Ln) = (max) 921 bits into GMSK (10×1) Bernoulli binary (10×1)D2 (10×1) Select Packet Size = [size, delay] using Callback InitFcn in model properties Packet Cyclic encoder (5×1)D2 (549×1)D3 Carrier freq Assemble various seed packets at mbps FH-CPM modulator Frequency hopping GFSK modulator (54900×1)D3 (54900×1) D3 (54900×1) Upconverter AWGN Carrier freq nfmt19937af, “seed” P library (54900×1) (54900×1) Downconverter D (54900×1)D To frame (54900×1) (549×1) Disassemble (5×1)D2 FH-FM Cyclic packet demodulator decoder Frequency hopping Shortened FM demodulator hamming (15×10) decoder Receiver D 15-FSK (54900×1) D Carrier freq Generate (54900×1) 15 possible carriers –12 MHz to 12 MHz D 6 U Hop frequency in MHz Frequency hopping code Channel Channel Transmitter (549) Channel (54900×1) (5×1)D2 RxPacket Open scopes Spectrum Close scope scopes Received signal spectrum (10×1) 0 s1 del (10×1) D2 Tx Align s2 (10×1) D2 0 Error rate 3 D2 s2 signals D5 RxPacket calculation 5.253e+05 delay Rx (10×1) Carrier BER (10×1) Align signals frequency BER calculation monitor 380 Delay Hop time will vary by changing packet size TxPacket s1 AWGN, additive white Gaussian noise; BER, bit error rate; FH-CPM, frequency hopping continuous phase modulation; FH-FM, frequency hopping frequency modulation; freq, frequency; FSK, frequency shift keying; GFSK, Gaussian frequency shift keying; GMSK, Gaussian minimum shift keying; Ln, length; NTmin, number of minimum time periods; PN, pseudo random; RxPacket, receive packet; TxPacket, transmit packet Figure 13. TTNT Simulink physical layer modulation virtual prototype. Figure 14. Netted ISR maritime interdiction scenario virtual prototype. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 31­­­­ K. D. Brown et al. C-IDE MATLAB system model Real-time workshop/ embedded coder Simulink system model System generator DSP compiler/ linker DSP device programming GPP compiler/ linker GPP device programming VHDL compiler/ linker VHDL device programming Reconfigurable multiprocessor prototype Executable build HDL IDE Executable code Concept M&S analytical TB Source code As a second example, consider the netted ISR communication network SM for the maritime interdiction scenario shown in Fig. 14. This VP enables exploration of operational performance sensitivity to communication link parameters such as quality of service, throughput, range, power, and bandwidth. Each of these exemplar virtual prototypes enabled rapid exploration of critical performance parameters in a lowcost-of-change environment. Concept Validation The SE IDE also includes source-code-generation toolsets for rapid prototyping (i.e., converting system SMs developed during concept exploration into a PoC physical prototype [PhP] whose response to physical environmental processes can be measured with calibrated equipment). The calibration enables quantification of SM confidence intervals when measurements are compared to simulated responses. To enable rapid, low-cost-of-change prototypes, rapid software prototype tools are used, as shown in Fig. 15. These tools convert SM into source code, which can be compiled into executable code for target processors. Figure 15. Rapid prototype auto-generation processing. DSP, digital signal processor; GPP, general-purpose processor; HDL, Hardware Description Language; M&S, modeling and simulation; TB, testbed; VHDL, Very High-Speed Integrated Circuit HDL. Alternative down-selection and optimization highlight how rapid concept engineering is achieved. As an example, consider a Tactical Targeting Network Technology (TTNT)16 surrogate modulator model, as shown in Fig. 13. This simulation model (SM) is only a portion of the communication physical layer processing but highlights the capability to test system performance sensitivity under a range of modulation parametric variations. NISR master reference architecture Requirements Software computing architecture Portable components segment (applications) Sensing applications Platform common services Logging Config Platform device services VM Data-processing applications Process 1 Process 2 Process N App N App 2 Reference architecture VM Distribution capabilities Dist WF fcn transport DNS/subnet formation Addressing services App 1 Transport services segment (network/communications services) WF functions Virtual machine (VM) GPS I/O services segment (networking services) VM Fusion applications Sensor 1 Sensor 2 Sensor N Platform-specific services segment (local core services) QoS Interworking fcn Power control Config Secured Red data service routing Mobility management Black routing Red QoS Constraints Black QoS Neighbor discovery Laboratory or demonstration environmental testbed Flow control Operating system segment OS kernel Partitioning File system Device driver Hypervisor Hardware architecture Digital hardware Waveform processor Device driver SysML updates/ modifications Application/ networking processor Switch Fabric Backplane switching Analog hardware Link-16 TTNT MADL CDL Calibrated V&V testing Future Automated code generation Reverse engineering SysML tools (MagicDraw, Rhaposody, etc.) Simulationdriven development 1 s Vc RC + 3 Ro + ÷ × × 1 S S _ + × +_ mode 4 Io >= 0 OR == 1 1/C Vc × ÷ + + RC Vo 1 y 2 Vs == 2 OR – + – double vL 1 s 1/L IL IL <0 Is × 0 Test lessons learned Terminal TX system model validation Difference Concept exploration Uplink channel impairments Terminal TX Model response System model testbed Ic double Hardware response Terminal TX hardware in the loop Executable code Custom code New source tracking code Legacy source code Concept validation Base station RX hardware Downlink channel impairments Satellite RX Satellite processing Satellite TX RL Simulink Figure 16. PhPs by automatic code generation. 32­­­­ Figure 17. Hardware/software-in-the-loop RX, receiver; TX, transmitter. (SiL) V&V TB. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept Stimulus equipment Measurement equipment Wireless MIMO channel emulator RF signal generator Digital oscilloscope Large-/small-scale fading Data pattern generator TX UUT Function/ noise generator Vector signal analyzer RX UUT Multipath fading Digital logic analyzer Doppler spread BERT Network analyzer Noise/ interference Figure 18. Communication V&V TB. BERT, bit error rate tester; MIMO, multiple-input and multiple-output; RX UUT, receive unit under test; TX UUT, transmit unit under test. SIL (10×1) Bernoulli binary (10×1)D2 TxPacket Cyclic encoder D3 FH-GMSK Demod (5×1)D2 (549×1)D3 AWGN Channel Transmitter Channel (54900×1)D3 Carrier freq (54900×1)D4 (54900×1)D3 (54900×1) Carrier Freq Assemble various seed packets at 1 Mbps (54900×1) (54900×1) Channel Open scopes Spectrum Close (5×1)D2 Disassemble (5×1)D2 scope scopes Cyclic RxPacket packet decoder Received signal Shortened FH-GMSK Demod spectrum hamming (15×10) decoder Receiver 0 D3 (10×1) s1 del (10×1) D2 Tx SIL TxPacket s1 Align 3 D2 (10×1) D2 0 Error rate s2 (10×1) s2 signals RxPacket calculation D5 5.13e+04 delay FH-GMSK Demod Rx BER (10×1) Align signals BER calculation (54900×1) D4 750 D4 D4 nfmt19937af, To Carrier freq Delay 15-FSK “Seed” frame Seed Generate (54900×1) 15 possible carriers –12 MHz to 12 MHz D4 6 U Hop frequency in MHz Carrier frequency monitor AWGN, additive white Gaussian noise; BER, bit error rate; freq, frequency; FSK, frequency shift keying; GMSK, Gaussian minimum shift keying; RxPacket, receive packet; TxPacket, transmit packet Frequency hopping code Figure 19. TTNT physical layer modulation SiL. Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 33­­­­ K. D. Brown et al. Reference Architecture SysML Rapid Prototyping An MBSE rapid software prototyping example includes a processing hardware and software reference architecture such as FACE, performance requirements, and resource constraints. System designers can leverage legacy code to prototype new source code. As shown in Fig. 16, the SE IDE provisioned with SysML (Systems Modeling Language) and UML (Unified Modeling Language) toolsets (reference templates and libraries) is capable of leveraging legacy design, integrating new requirements within a Figure 20. TTNT physical layer modulation PiL. reference architecture, and generating new source code. This example demonstrates how legacy code is Fig. 18 can be integrated with the concept exploration reverse-engineered by a SysML17 tool, such as MagicDraw environment by applying the same stimulus used in the (http://www.nomagic.com/products/magicdraw.htm) or SM, and responses from the V&V TB can be compared Rhapsody (http://www-142.ibm.com/software/products/ to the simulated responses in the SM. us/en/ratirhapfami/). The reverse engineering produces Consider the rapid prototyping example in Fig. 19; SysML diagrams of what the code represents and how it is a software-in-the-loop (SiL) emulation, which is they are interconnected and can be reused in the new derived from the previous TTNT modulation SM. The system design. Based on the requirements and reference SiL provides a capability to emulate the behavior of architecture, the system designer develops a model of the 18 source code generated from the SM. system in SysML and UML. Throughout the system As a second example, consider the processor-in-thedesign process, Simulink (http://www.mathworks.com) loop (PiL) shown in Fig. 20; it is a digital signal processor code can be generated/developed to simulate target comhardware emulation derived from the same SM. It proponents. After the system has been modeled, code that represents the system is automatically generated. Custom vides a capability to embed physical hardware running code can be written for any components where automatic the SiL software within the SM. Implementation errors code generation is not possible. The SysML tool then associated with fixed-point precision, timing, and clocktracks any custom code inserted or added to include in ing can be evaluated with the PiL. Both the SiL and future automatic code generation. Automatic test cases are also generLaptop-UAV ated from the requirements stored in SysML. The automatic code generation can also be done for a partial system model or for subsystems to test the system as the model is being developed to support an incremental or spiral development. The PoC PhP can be stressed SBC-Command by mechanical, electrical, or environmental conditions in an integrated hardware/software-inthe-loop V&V testbed (TB), as shown in Fig. 17. These tests can SBC-Sensor be conducted within a laboratory Laptop-Cutter Laptop-UAV or extended to include field-test demonstrations. For instance, the communication V&V TB shown in Figure 21. Netted ISR physical layer prototype. SBC, single-board computer. 34­­­­ Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest Model-Based Design for a Netted ISR Concept MBSE capability Reduced cycle times System of systems interoperability Design optimization across broad trade space Cross domain effects-based analysis Extending maturity and capability Institutionalized MBSE across academia/ industry Defined MBSE theory, ontology, and formalisms Maturity Well-defined MBSE Distributed and secure model repositories crossing multiple domains Matured MBSE methods and metrics, integrated system/HW/SW models Ad hoc MBSE document centric Refer to activities in the following areas: Architecture model integrated with simulation, analysis, and visualization Emerging MBSE standards 2010 • Planning and support • Research • Standards development • Processes, practices, and methods • Tools and technology enhancements • Outreach, training, and education 2020 2025 Figure 22. INCOSE MBSE methodology maturity. (Reprinted with permission from Ref. 19, © INCOSE.) the PiL were auto-generated and compiled in minutes. Changes to the SM can be rapidly transferred to both emulations for verification testing. As a third example, consider the netted ISR network PoC PhP shown in Fig. 21. In this case, physical hardware has been connected to nodes in the previously discussed VP. Operational hardware hosting operational software can execute in real time. Communication traffic is generated by the PhP, exchanged between the VP nodes, and processed by the destination PhP nodes. In this manner, the hardware-in-the-loop enables verification of node application, networking, and communication services while retaining a low-cost-of-change environment for the location, ranges, and wired and wireless link effects. Link latency, quality of service, and throughput can rapidly and easily be manipulated to quantify performance sensitivities of an operational scenario. Integrated Validation Environment The SE IDE PhP can be extended to field demonstrations (for example, consider the UAV). The netted ISR PoC PhP can be deployed on a constellation of airborne platforms and demonstrated under actual operational conditions to validate the concept. A similar test stimulus used in the SM can be applied to the field demonstration hardware, and responses can be measured and compared to the simulated responses in the SM. CONCLUSION The APL MBSE IDE has been introduced and applied to the anti-access/area-denial netted ISR case and a growing list of other SE projects. The IDE infra- structure facilitates effective, agile, rapid, and affordable concept exploration, verification, and validation for complex SoS such as netted ISR. For the netted ISR case, a rapid innovation cycle project over the course of 4 months used an IDE to define, model, prototype, and produce initial results that indicated that 30% fewer sensor platforms and at least 25% fewer operators were necessary for one scenario, contributing to the potential for significant, compounded life-cycle savings with netted compared to traditional ISR SoS. Studies conducted by the National Defense Industrial Association, INCOSE, and other SE organizations recommend adoption of MBSE methodologies based on member-documented project cost and schedule reductions.19–21 The INCOSE MBSE roadmap is shown in Fig. 22. APL is midway through maturing its brand of MBSE methodology. REFERENCES 1Shaffer, A., Current S&T Priorities and the Future of DoD S&T, Department of Defense, Washington, DC (29 Oct 2013), http:// www.acq.osd.mil/chieftechnologist/publications/docs/Current_ST_ priorities_and_the_Future_of_DOD_ST.pdf. 2Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics, Report of the Joint Defense Science Board Intelligence Science Board Task Force on Integrating Sensor-Collected Intelligence, Defense Science Board, Washington, DC (Nov 2008). 3Dunaway, D., “Creating Integrated Warfighting Capabilities,” Proceedings Magazine 139/8/1,326 (2103). 4Joint Operational Access Concept (JOAC), version 1.0, Joint Chiefs of Staff, Washington, DC (Jan 2012). 5United States Joint Forces Command, Commander’s Handbook for Persistent Surveillance, version 1.0, Joint Warfighting Center, Joint Doctrine Support Division, Suffolk, VA (20 Jun 2011). 6Joint Publication 3-60 (JP 3-60), Joint Targeting, Joint Chiefs of Staff, Washington, DC (31 Jan 2013). 7Newman, A. J., and Mitzel, G. E., “Upstream Data Fusion: History, Technical Overview, and Applications to Critical Challenges,” Johns Hopkins APL Tech. Dig. 31(3), 215–233 (2013). Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest 35­­­­ K. D. Brown et al. 8Newman, A. J., and DeSena, J., “Closed-Loop Collaborative Intelligence, Surveillance, and Reconnaissance Resource Management,” Johns Hopkins APL Tech. Dig. 31(3), 183–214 (2013). 9Connor, T., and Wong, H., “Emergent Properties,” The Stanford Encyclopedia of Philosophy, Spring 2012 Ed., E. N. Zalta (ed.), last modified February 12, 2012, http://plato.stanford.edu/entries/ properties-emergent/. 10Alberts, D. S., and Hayes, R. E., Understanding Command and Control, Command and Control Research Program Publication Series, Washington, DC (2006). 11U.S. Navy Information Dominance Roadmap, 2013–2028, U.S. Navy, Washington, DC (Mar 2013). 12Seymour, J. S., and O’Driscoll M. 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MBSE Symp.: INCOSE Chesapeake Chapter and JHU/APL (29 Mar 2014). 14Defense Advanced Research Projects Agency (DARPA), DARPABAA-14-02, “Communications in Contested Environments (C2E),” Solicitation Number DARPA-BAA-14-02 (Jan 2014). 15Open Group, Technical Standard for Future Airborne Capability Environment (FACETM), Edition 2.0 (Feb 2013), http://www.opengroup. org/face/tech-standard-2. 16U.S. Department of Defense, “Waveform Specification JTRS Software Waveform,” Tactical Targeting Networking Technology (TTNT), Draft Revision 4.0 (Jul 2005). 17Object Management Group, “Documents Associated With SysML Version 1.2,” http://www.omg.org/spec/SysML/1.2/. 18Object Management Group, “Index of /spec/UML/2.3/Superstructure,” http://www.omg.org/spec/UML/2.3/Superstructure/. 19Friedenthal, S., Griego, R., and Sampson, M., “INCOSE Model Based Systems Engineering (MBSE) Initiative,” in Proc. INCOSE 2007 Symp., San Diego, CA, p. 17 (2007), https://www.incose.org/ enchantment/docs/07Docs/07Jul_4MBSEroadmap.pdf. 20Hause, M., Stuart, A., Richards, D., and Holt, J. “Testing Safety Critical Systems with SysML/UML,” in Proc. 15th IEEE Intl. Conf. on Engineering of Complex Computer Systems, Oxford, UK, pp. 325–330 (2010). 21National Defense Industrial Association (NDIA) Systems Engineering Division M&S Committee, “Final Report of the Model Based Engineering (MBE) Subcommittee,” NDIA, Arlington, VA (10 Feb 2011). THE AUTHORS K. Dewayne Brown is a communications systems engineer and Supervisor of the Resilient Tactical Communications Section in APL’s Asymmetric Operations Sector. He provided MBSE expertise for the ADI C2E and netted ISR projects. Mary Beth A. Chipkevich is a Principal Professional Staff member in the Force Projection Sector and Program Manager for Unmanned Systems and Autonomous Technologies in the Precision Strike Mission Area. Robert J. Bamberger is a member of APL’s Principal Professional Staff and Supervisor of the Autonomy Section in the Research and Exploratory Development Department. He was the Technical Lead for the Defense Advanced Research Projects Agency’s Airborne Dominance Initiative (ADI) Communications in a Contested Environment (C2E) project. Tam-Thanh C. Huang is a member of APL’s Senior Professional Staff and is a communications engineer with extensive experience in softwaredefined radio design and implementation of various military waveforms. Mark A. Matties is a member of APL’s Senior Professional Staff in the Communication and Networking Systems Group and Supervisor of the Advanced Software Defined Networking Section. He currently researches the security and advanced applications of software-defined networking to provide secure, resilient networks. James D. Reeves is a member of APL’s Senior Professional Staff and is a systems, network, and information systems security engineer for advanced technologies in the Aerospace Systems Analysis Group of the Precision Strike Mission Area. He was the Lead Systems Engineer for the netted ISR project. Christopher A. Rouff is a member of APL’s Senior Professional Staff in the Communication and Networking Systems Group. He is a computer scientist doing research in automatic code generation from system models to quickly produce simulations and prototypes of new system concepts. The ADI and netted ISR teams can be contacted through the Program Manager, Mary Beth Chipkevich. Her e-mail address is mary.beth.chipkevich@jhuapl.edu. 36­­­­ Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest