Harry M. Heckathorn

Strategic Scene Generation Model: baseline and operational software

The Strategic Defense Initiative (SDI) must simulate the detection, acquisition, discrimination and tracking of anticipated targets and predict the effect of natural and man-made background phenomena on optical sensor systems designed to perform these tasks. NRL is developing such a capability using a computerized methodology to provide modeled data in the form of digital realizations of complex, dynamic scenes. The Strategic Scene Generation Model (SSGM) is designed to integrate state-of-science knowledge, data bases and computerized phenomenology models to simulate strategic engagement scenarios and to support the design, development and test of advanced surveillance systems. Multi-phenomenology scenes are produced from validated codes--thereby serving as a traceable standard against which different SDI concepts and designs can be tested. This paper describes the SSGM design architecture, the software modules and databases which are used to create scene elements, the synthesis of deterministic and/or stochastic structured scene elements into composite scenes, the software system to manage the various databases and digital image libraries, and verification and validation by comparison with empirical data. The focus will be on the functionality of the SSGM Phase II Baseline MOdel (SSGMB) whose implementation is complete Recent enhancements for Theater Missile Defense will also be presented as will the development plan for the SSGM Phase III Operational Model (SSGMO) whose development has just begun.

Synthetic scene generation model (SSGM R7.0)

BMDO must simulate the detection, acquisition, discrimination and tracking of anticipated targets and predict the effect of natural and man-made backgrounds and environmental phenomena on optical and radar sensor systems designed to perform these tasks. The SSGM is designed to integrate state-of-science knowledge, data bases and valid phenomenology models to simulate ballistic missile engagement scenarios for both passive and active sensors aboard surveillance system platforms and defensive interceptor missiles -- thereby serving as a traceable standard against which different BMDO concepts and designs can be evaluated. This paper concentrates on describing the current capabilities and planned development efforts for SSGM. The focus will be on the functionality of the SSGM Release 7.0 and the planned development effort for subsequent SSGM releases. We shall demonstrate the current SSGM capability (R7.0, January 1996) with sample multi-phenomenology output scenes and videos. New capabilities include realistic 6-DOF dynamics for targets, simulated target radar cross section correlated with IR information, and authorative target model data sets based on actual flight experiments.

Object-oriented design of a scene generation simulation

This paper describes the object-oriented design of a physics-based simulation called the strategic scene generation model. Scientific codes in general, and physics codes in particular, have suffered from a lack of application of object-oriented technology to their domain problems. The main result of this paper is that by using the object-oriented concepts of dynamic binding and data encapsulation, integration of disparate physics models written with different programming styles by different groups becomes much easier, and the time to maintain such code is greatly reduced. The application of such techniques in other scientific domains ought to achieve similar results.<<ETX>>

Strategic scene generation model

The Strategic Defense Initiative (SDI) must simulate the detection, acquisition, discrimination and tracking of anticipated targets and predict the effect of natural and man-made background phenomena on optical sensor systems designed to perform these tasks. NRL is developing such a capability using a computerized methodology to provide modeled data in the form of digital realizations of complex, dynamic scenes. The Strategic Scene Generation Model (SSGM) is designed to integrate state-of-science knowledge, data bases and computerized phenomenology models to simulate strategic engagement scenarios and to support the design, development and test of advanced surveillance systems. Multi-phenomenology scenes are produced from validated codes--thereby serving as a standard against which different SDI concepts and designs can be tested. This paper describes the SSGM design architecture, the software modules and databases which are used to create scene elements, the synthesis of deterministic and/or stochastic structured scene elements into composite scenes, the software system to manage the various databases and digital image libraries, and verification and validation by comparison with measured data. The focus will be on the functionality and development schedule of the Baseline Model (SSGMB) which is currently being implemented.

Microchannel intensified electrography

Electrography is, in many respects, a nearly ideal electronic imaging technique. However, at very low light levels, although individual photoelectron events are in principle detectable in the film images, limitations are imposed by microphotometer and emulsion grain noise. The use of microchannel intensification allows individual photoelectron events to be unambiguously detectable and measurable, with little loss in achievable resolution. This significantly enhances the capabilities of electrographic detectors for use in imagery and spectrography of faint, diffuse objects or in applications which require a fast time response. We have conducted a quantitative study of the gains in detectivity and signal-to-noise ratio provided by this technique, through microphotometry and computer analysis of images of identical or similar laboratory light sources, using both unintensified and microchannel-intensified electrographic Schmidt cameras. We describe applications of the technique to far-ultraviolet wide-field-imaging and nebular spectrograph experiments, both of which have been used in sounding rocket flights and are planned for near-future Shuttle missions.

Physics-based, high-fidelity simulation: strategic scene generation model

This paper describes a computerized system to generate reliable line-of-sight radiometry and time-sequenced digital images in support of the design, development and test of advanced strategic surveillance systems and for strategic engagement simulations required by the Ballistic Missile Defense Organization (BMDO). The Naval Research Laboratory (NRL) is developing the Strategic Scene Generation Model (SSOM) to provide valid images, and the capability to generate them, to various BMDO program elements and technology demonstration and measurements programs - thereby serving as a standard against which different BMD concepts and designs can be tested. Consequently, the SSOM has emerged as a highly visible focus for the ongoing development of phenomenology models and currently provides many projects in the BMD community with integrated, consistent, dependable, accessible and affordable state-of-science modeling and simulation capability.

Reduction and Analysis Of Electrographic Imagery And Spectra

The photometric quality of film recorded imagery from electrographic detectors such as those proposed for use on the STARLAB and SPACE SCHMIDT telescopes and on the NRL-803 experiment 2 requires that special attention be given to the information-extraction (digitization) and data reduction and analysis techniques. These will be discussed in detail and illustrated by example. An initial attempt at ex post facto image motion compensation, which may be required for cases of inadequate pointing stabilization, and results of recent experiments in post-development autoradiographic enhancement of weakly exposed electrographic images will be described.

SSGM : From serial to parallel processing using PVM

Physics-Based Distributed Simulation using Optimistic Computing makes innovative use of emerging technologies to achieve faster generation of complex, multi-component physics-based information. The computational results are used in performing simulations that probe engineering issues relevant to system acquisition and in high-fidelity real- time distributed simulations. Four synergistic technologies are being brought together to bare on the question of high- fidelity scene generation to support HWIL simulation: integrating architectures for state-of-science, physics- based phenomenology models; protocols to support heterogeneous computers operating on a single network; accessible high-capacity networks; and optimistic synchronization to achieve demanding computational speed requirements and to overcome latency problems in real-time systems. We wish to report the first results from a multi- layer demonstration project that the Naval Research Laboratory has undertaken for the Ballistic Missile Defense Organization. We have made progress using the first three technologies and are planning to address optimistic synchronization in the near-future.

Synthetic scene generation model (SSGM R6.0)

The Ballistic Missile Defense Organization (BMDO) must simulate the detection, acquisition, discrimination, and tracking of anticipated targets and predict the effect of natural and man- made background phenomena on optical sensor systems designed to perform these tasks. NRL is developing such a capability using a computerized methodology to provide modeled data in the form of digital realizations of complex, dynamic scenes. The Synthetic Scene Generation Model (SSGM) is designed to integrate state-of-science knowledge, data bases, and computerized phenomenology models to simulate ballistic missile engagement scenarios and to support the design, development, and test of advanced electro-optical interceptor and surveillance systems. Multi-phenomenology scenes are produced from validated codes -- thereby serving as a traceable standard against which different BMDO concepts and designs can be tested. This paper describes the SSGM software architecture, the software modules and databases that are used to create scene elements, the synthesis of deterministic and/or stochastic structured scene elements into composite scenes, the software system to manage the various databases and digital image libraries, the ancillary software tool suite, and verification and validation by comparison with empirical data. The focus is on the functionality of the SSGM Release 6.0, and the planned development effort for subsequent SSGM releases.

Backgrounds Data Center

The Backgrounds Data Center (BDC) is the designated archive for backgrounds data collected by Ballistic Missile Defense Organization (BMDO) programs, some of which include ultraviolet sensors. Currently, the BDC holds ultraviolet data from the IBSS, UVPI, UVLIM, and FUVCAM sensors. The BDC will also be the prime archive for Midcourse Space Experiment (MSX) data and is prepared to negotiate with program managers to handle other datasets. The purpose of the BDC is to make data accessible to users and to assist them in analyzing it. The BDC maintains the Science Catalog Information Exchange System (SCIES) allowing remote users to log in, read or post notices about current programs, search the catalogs for datasets of interest, and submit orders for data. On-site facilities are also available for the analysis of data, and consist of VMS and UNIX workstations with access to software analysis packages such as IDL, IRAF, and Khoros. Either on-site or remotely, users can employ the BDC-developed graphical user interface called the Visual Interface for Space and Terrestrial Analysis (VISTA) to generate catalog queries and to display and analyze data. SCIES and VISTA permit nearly complete access to BDC services and capabilities without the need to be physically present at the data center.