2009 Users' Conference Resources

• COTS Interoperability, Tom Urie, AGI
• Integrating STK and QualNet, Dr. David Finkleman, CSSI
• STK/Analyzer and STK/Missile Modeling Tools, Amanda Brewer, AGI
• STK/Terrain, Imagery & Maps, Ronnie Allan, AGI
• Trajectory Optimization Using STK, Patrick Wiliams, PSU
• Using STK/Coverage Point Files for 4D Analysis, Daniel Benedict, SAIC
• What is Insight3D, Deron Ohlarik, AGI
• Wireless InSite Real-Time: Site-Specific Urban Propagation Prediction in Real Time, Greg Skidmore, Remcom

Communications

• ArrayLab and STK: Dynamic Mission-Specific Communication Performance
  Kathy Minear, Harris Corporation
  
  

  Harris Corporation's dynamic system simulation tool ArrayLab analyzes communication performance of antenna arrays on dynamically maneuvering spacecraft or celestial bodies. The arrays feature arbitrarily placed and oriented elements in a wide variety of configurations and are controlled using adaptive and model-based algorithms. ArrayLab, written entirely in Mathwork's MATLAB, directly and interactively interfaces with STK for pertinent space-time data needed to analyze multiple simultaneous links. Together, the software programs provide step-by-step communication analysis and visualization throughout the mission scenario. This presentation will concentrate on how the merger of the two tools simplifies communication systems design trades and allows performance to be accessed for the specific orientations and positions of the proposed array as it communicates with the targets of interest.

• Improved Communications Hardware Testing Using STK
  Steve Williams, RT Logic
  
  

  More comprehensive testing of RF communications hardware is achieved with lower cost and risk by using AGI's STK application to realistically simulate the channel conditions that will be experienced in nature.

  RT logic describes how STK is used to control laboratory RF test and measurement equipment to precisely create the received powers, antenna geometry, Doppler shifts, range delay, attenuation, noise, interference and other RF channel characteristics and behaviors experienced in the field. This allows many more test scenarios to be readily evaluated including those that would be impossible, dangerous and/or too expensive to conduct outside the lab. Recent applications to missile test range planning and the design of a satellite crosslink are discussed to demonstrate how higher levels of mission readiness confidence were achieved through this pre-mission, hardware-in-the-loop, full-path testing approach. GIS

GIS

• An Introduction and Update to the CJMTK Geospatial Appliance
  Brett Cameron, Northrop Grumman
  
  

  The CJMTK Geospatial Appliance (CGA) offers the AGI user community a turnkey solution to the NGA geospatial data needs. The CGA is a bundle of hardware, software and geospatial data that provides out-of-the-box functionality throughout the hosting of application-ready data. This data is hosted via WMS, KML, Rest, Geodatabase or file-sharing access methods. Data includes the entire holdings of the NGA unclassified VPF, DTED and RPF data sets.

• A Mission Planning Tool for Maritime Operations
  Mike Gingell, General Dynamics Canada
  
  

  General Dynamics Canada and Defence R&D Canada (DRDC) are developing a Mission Planning Tool (MPT) for Canadian Forces maritime operations. The MPT will be used for detailed mission planning and options analysis ahead of deployment; for guiding mission execution in theatre; and for de-briefing post deployment. The MPT will also support training and tactics development. The MPT is based on a service-oriented architecture (SOA) that provides common data-sharing capability for command and control (C2) and allows the system to take advantage of network resources such as environmental or geographic data when available, or to operate independently when connectivity is poor or disrupted. To meet the operational requirement, the MPT also has to have several other demanding capabilities. These include high-performance Geographical Information System (GIS) functionality, the ability to execute external custom models and the ability to simulate and track multiple platforms in the scenario.

• Visual Analysis of Vehicle Simulations, INS/GPS Solutions and Real-World Data
  Robert Addiss, senior software engineer, CAST Navigation, LLC
  
  

  CAST Navigation, LLC, used STK Engine to create a 2-D and 3-D modeling and simulation application that tested aircraft missions and included the plane's ability to access GPS satellites. This presentation will describe the challenges presented to CAST by its potential customer and how STK Engine software was critical to creating a solution that exceeded expectations within an aggressive time schedule.

ISR Mission Planning

• Assessing ISR and Comm Planning
  Lt. Col. Brian Zacherl, operations analyst, United States Marine Corps
  
  

  The United States Marine Corps, with the help of AGI, has built and deployed two ruggedized computers in Afghanistan that use STK to assess the success of intelligence, surveillance and reconnaissance (ISR) and communications planning. Operations currently require a trained analyst, but the Marines are working toward a deployable application for untrained users.

• Configuring STK to Drive Operational and Concept Analysis
  Arthur Brooks, senior systems engineer, L-3 Integrated Systems
  
  

  L-3 Integrated Systems, Mission Integration Division, Modeling Simulation and Operations Analysis (MSOA) Group supports analysis, operational, system and design concepts through a robust constructive modeling and simulation environment. Using STK Professional Edition, STK/Coverage, STK/Aircraft Mission Modeler and STK/Communications, the MSOA has added credibility to proposal submissions and shaped early phase program development. This presentation will demonstrate how the MSOA group configures STK to predicted performance, dependency, sensitivity, utility and inefficiency to support existing and future programs.

Missiles

• Custom Logic for Airborne Early Warning
  Timothy Booher, US Air Force, Pentagon
  
  

  How much is a pound of ISR worth? What impact does sensor capability have on a military campaign? How does ISR reduce risk in the integrated air and missile defense mission? The answers to these questions, while difficult, are of active interest to Pentagon senior leadership. This presentation will address the complexities of modeling ISR and how Headquarters USAF A9 integrated STK with MATLAB, Ruby and Google Picasa to illuminate the risk inherent in various future ISR acquisition programs. The flexibility, support and visual feedback available in STK enabled a year-long study to be completed in a month—in time to influence the acquisition of a major ISR program.

• Missile Flight Test Planning and Analysis with STK
  Franklin Grose, senior space systems analyst, SAIC
  
  

  The System Test and Evaluation Planning Analysis Lab (STEPAL) exists to provide the Missile Defense Agency (MDA) Ballistic Missile Defense System with an analytical resource to develop and assess flight test events that demonstrate the system's inherent performance capability. Since its inception in 2002, STEPAL has relied upon STK and other AGI products to examine threat capability, the system's operational characteristics, range safety compliance and engagement parameters to assess how flight tests fit into the operational space. This presentation will discuss key technical capabilities of AGI's software that make it an invaluable tool for STEPAL analysts and how STK contributes directly to the successful execution of the STEPAL mission.

• Optimal Weapon Allocation Solution Built With AGI Software
  Dr. Shaonn Shon, Signature Analytics
  
  

  Signature Analytics LLC conducted an 'Automated Weapon-Target Allocation Optimization' study under an MDA SBIR Solicitation topic on Battle Management and Planning Aids. The Solicitation called for "a feasibility study of innovative, advanced and robust weapon target allocation algorithms applicable to missile defense, to extend, enhance, optimize and automate the BMDS battle management and planning capabilities." This presentation discusses how the breadth, flexibility and extensibility of AGI software were leveraged to eliminate much of the time and cost of demonstrating the solution. Custom code was integrated with STK, STK/Analyzer, STK/Scheduler and STK/Missile Modeling Tools into a weapon allocation solution. This allowed Signature Analytics to focus on its expertise, demonstrate a solution in just six months and capture a follow-on contract award.

Space

• Development, Deployment, Training and Education Using STK
  Joyce Stivers, principal analyst, Northrop Grumman
  
  

  Operators supporting Air Force Space Command are facing rapidly changing mission objectives. These changes generate new requirements that need to be addressed quickly with limited budgets. Further, operators are frequently expected to perform tasks concerning spacecraft operations for which they are minimally prepared. This challenging environment requires:

  • a solution that provides efficient operations with systematic and repeatable processes
  • a diverse set of validated algorithms coupled with the use of Air Force Standards software
  • a training and educational program designed to prepare the operators for the rigors of spacecraft operations.

  This presentation will describe the OPS Tool Set, built on AGI's STK Engine and implemented in an operational environment. It will cover why STK Engine is a key solution for this type of environment and describe a series of training tutorials that have been created to support the operational application.

• IBEX Mission Planning and Operations
  Michel Loucks, owner and principal astrodynamics scientist, Space Exploration Engineering Co.
  
  

  NASA's Interstellar Boundary Explorer (IBEX) mission was successfully launched on October 19, 2008, and is now exploring the interaction between solar wind and the interstellar medium. Mike served as the trajectory lead for the Flight Dynamics Team that used STK/Astrogator as the sole mission-planning tool and Orbit Determination Tool Kit for orbit determination. The flexibility and power of these tools allowed operators to completely re-plan the mission several times after launch in order to accommodate additional requirements from the science team.
  
  Mike will describe and demonstrate:

  • Techniques used in operations to plan the trajectory ascent, accounting for launch and maneuver dispersions.
  • Results of maneuver planning and calibration.
  • Reconstruction of the launch and solid rocket motor firing.
  • Models and algorithms used to plan multiple-maneuver phasing loop ascent.
  • How the final mission orbit was achieved.
  • How Monte Carlo analysis during operations ensure that the science objectives will be met over the two-year mission lifetime.
  
  
• Kepler Dust Cover Ejection Event Design and Optimization
  David Acton, Ball Aerospace & Technologies Corp.
  
  

  STK Professional, Astrogator, and Analyzer were used to design and analyze a dust-cover release attitude for the Kepler spacecraft, with the goal of ensuring safe relative trajectories after the release event. Kepler is a deep space NASA mission intended to find Earth-like planets around other stars. This presentation will cover how the software was employed for mission planning and in real-time operations.

• Satellite Maneuver and Catalog Mistag Detection via TLE Analysis
  Dr. Jacob Griesbach, Chief Scientist, Agilex Technologies
  
  

  Using a MATLAB script through the STK/Integration Object Model interface, Dr. Griesbach identifies satellite maneuvers and mistags in the satellite catalog database. He will describe how, by using STK to propagate forward a given satellite’s TLE data to the time of the next TLE update, the prior (predicted) and updated positions may be simply differenced. The resulting difference measurements give observations regarding estimating the expected TLE positional error uncertainty. A byproduct of this analysis is that satellite maneuvers exceeding the error uncertainty result in TLE difference spikes. These spikes may be simply thresholded to detect maneuvers, or with a much larger threshold, catalog mistag errors.

• STK in Launch Range Support Analysis
  Jay Pittman, Range and Mission Management Office chief, Wallops Research Range
  
  

  The Wallops Research Range is NASA's only launch range. It provides launch support for operational as well as first-of-kind launch vehicles, payloads and technologies. In 2004, the range initiated the STK-based Mission Planning Laboratory (MPL) to assist its operations teams with planning and optimization tasks associated with flight operations support. The effort has been an overwhelming success and has grown beyond its original intent. This presentation will describe how the MPL is used pre-and post-flight to visualize, analyze and optimize mission specifications and how it has aided in the growth of the Wallops range.

• Aircraft Mission Modeler Software Architecture
  Tom Neely, AGI
  
  

  The AMM expert system comprises a large COM API with more than 200 objects implementing 500 interfaces along with 100 ActiveX controls. This talk will examine how this system is integrated with STK and how it can be integrated with other applications.

• Attitude Modeling in STK
  Dr. Sergei Tanygin, AGI
  
  

  Attitude modeling is an important part of many computations performed in STK including sensor targeting and intervisibility analysis, force modeling, antenna link budget, sensor swath, coverage and visualization. The models range from simple inertially fixed alignment to numerically integrated attitude. The models can be customized using various configuration parameters and new models can be created using custom plugins and components from Vector Geometry Tool. Attitude information is available in various reports, graphs and 3D displays. It can also be exported into a file for further processing outside of STK. Conversely, external attitude data can be imported into STK via file or Connect interface. STK 9 includes several new types of attitude models available via the Vector Geometry Tool.

• Covariance Realism
  David A. Vallado, Center for Space Standards & Innovation
  
  

  Covariance information from orbit determination is becoming a popular means to assess the validity of many space operations. There have been scattered claims and discussion of realistic covariance, but few, if any, detailed studies to demonstrate the actual performance against independent references. This paper shows the performance of predicted ephemeris errors against reference and precision orbits, to what the covariance propagation provides. Several satellite orbital classes are studied.

• Intimate Communication Network Simulation with STK and QualNet
  Dr. David Finkleman, CSSI
  
  

  This presentation is an introduction to new collaboration between STK and communication network simulations. The new paradigm is to replace QualNet physical layer calls with the rich STK physical layer, as opposed to the previous approach where communication transactions controlled through applications were invoked only when all STK constraints were satisfied. Our experience with this important collaboration led to a more intimate exchange beyond STK Connect commands. The fundamental exchange objects are QualNet network interfaces. These interfaces acquire properties of transmitters and receivers in STK with the attributes that the communication objects inherit from sensors and platforms. Interfaces on host objects can be linked wirelessly or assigned to wireless subnets. The STK and QualNet object browsers are available in the same graphical user interface. The user can coordinate and execute both simulations simultaneously. Using practical airborne relay and satellite scenarios, we will show that physical access is necessary but not sufficient. We will demonstrate how higher layer network interactions and background traffic can inhibit links that enjoy complete physical access.

• Maximizing STK 9's Automation and SOA Capabilities
  Dr. T.S. Kelso, Center for Space Standards & Innovation
  
  

  Many users operate in an environment where analysts must perform structured tasks with standard data. Oftentimes, these analysts need to use the power of STK but may have rudimentary skills in implementing their workflows in a standardized fashion that ensures effective use of their time. The good news is that STK 9 incorporates several new features that make it easy to deploy standardized workflows that use approved data sources. We will examine how standardized workflows can be deployed from a corporate Intranet or the Internet to provide STK-based tools for analysis. Examples from Rev 2 of SOCRATES-GEO will be used to illustrate how this supports conjunction monitoring.

• Methods of Orbit Propagation
  Dr. Vince Coppola, AGI
  
  

  AGI products model orbit trajectories in many ways. In this presentation, a variety of methods including closed-form analytical solutions, general perturbations, semi-analytic solutions and special perturbations will be described. We will discuss advantages and disadvantages of the various methods, and their applications with AGI products.

• Modeling Antenna Attitude and Positional Offsets
  Dr. Haroon Rashid, AGI
  
  

  This presentation focuses on the enhancements made to the STK/Communications module for more accurately modeling antenna attitude and positional offsets relative to the parent object. This becomes critical when computing access intervals and modeling link degradation due to obscuration of the parent body. This presentation will also touch on the new STK 9 antenna object and best practices for using it in modeling communications systems.

• Modeling Dynamic Urban Propagation Loss
  Dr. Haroon Rashid, AGI
  
  

  Computing RF urban propagation loss is a challenging task due to high barriers imposed by the urban construction. The line of sight (LOS) obstructions due to buildings, reflections from the building faces, multipath echoes and propagation through walls present tricky situations. The problem can be further compounded by the dynamics of the objects. One or both terminals of a communications link may be mobile at the same time and may be moving in or out of the urban environment. We review several possible configurations in this session. We start with the communications terminals in space and move toward an urban area, covering situations where one terminal is in an urban environment, including the case where both terminals may be outside the urban area but the communications may be passing through or grazing the urban landscape. A couple of examples are presented and a possible future development direction is discussed.

• Moving Heaven and Earth: Implementing the International Celestial Reference Frame
  John Seago, AGI
  
  

  The IAU 2000A precession-nutation theory relates the International Celestial Reference Frame (ICRF) to the International Terrestrial Reference Frame (ITRF). This new theory became the official IAU standard in 2003. Unfortunately, we now have several documented or implemented standards that relate the ICRF and ITRF but differ to within several micro-arcseconds. These differences are mainly caused by changes of variables and very slight changes in modeling, and are fairly close to the original level of precision of the IAU 2000A nutation model (one micro-arcsecond). For example, the IAU replaced the IAU 2000A precession component with a new precession model that officially went into effect January 2009. AGI has now implemented many of these methods, but added a bonus method: one that maintains the original level of precision but runs almost 400 times faster.

• New Computational Tools for STK 9
  Dr. Sergei Tanygin, AGI
  
  

  Timeline and Calculation tools are developed to unify, standardize and customize use of time and other calculations within STK. The tools are designed using the same methodology as Vector Geometry Tool. This includes having various types of components for different calculations, placing these components within a common browser, accessing them by name via GUI, Connect and eventually Object Model, providing a number of pre-configured components, creating new custom components using existing components and using template components for all instances of the same STK object type.

• Powered Missile Flight Simulation Using STK/Missile Modeling Tools
  Chris Weekley, Science Applications International Corporation (SAIC)
  
  

  For designers and analysts of ballistic missiles, kinetic interceptors, sensor systems and integrated missile defense architectures, STK/Missile Modeling Tools (STK/MMT) simulates threat trajectories, intercept engagements and defense system performance. STK/MMT delivers system-level fidelity without complexity. This allows users to incorporate realistic missile simulation into analysis without specialized training or knowledge. This presentation describes the background and modeling detail employed in STK/MMT to simulate boost, midcourse and terminal phases of ballistic missile trajectories. Topics include software heritage to the Strategic and Theater Attack Modeling Process (STAMP) application funded by the National Air & Space Intelligence Center (NASIC) and modeling approaches for gravity, atmospheric drag, propulsion, guidance, post-boost vehicle maneuvers, free flight and reentry.

• SensorCAD Under the Hood: Radiometrics and the Electro-Optical Sensor Model
  Bob Anderson, Space Dynamics Lab - Utah State University
  
  

  This presentation will introduce the measurement of optical radiation as it relates to the SensorCAD Electro-Optical sensor model. Topics covered include:

  • Optical radiation and its generation by sources being imaged and its transport to the sensor
  • Transformation of the optical radiation into a digital readout
  • Noise and Signal to Noise Ratio

  Related terms and their meanings, e.g. dynamic range, quantum efficiency, relative spectral response

• Space Environment and Effects Toolkit (SEET) Technical Primer
  Dr. Richard A. Quinn and Paul P. Whelan, Atmospheric and Environmental Research, Inc. (AER)
  
  

  AER's Space Environment and Effects Toolkit (SEET) provides extensive modeling of the near-Earth space environment, with the capability to predict various effects on space vehicles. SEET's functionality is provided by six components consisting of scientific models of the space environment, including: Radiation Environment, South Atlantic Anomaly (SAA) Transit, Particle Impacts, Near-Earth Heavy Ion Environment, Vehicle Temperature and Magnetic Fields. These components are seamlessly integrated into the overall STK user interface and fully accessible through STK Engine as well. This talk will focus on giving a technical underpinning for the SEET, SAA-Transit Component in the context of a typical use case. The SAA is a near-Earth region of highly energetic charged particles which can easily penetrate spacecraft and create negative impacts on internal electronics. Impacts include single-event upsets (SEUs) and internal deep-dielectric charging/discharging. The current SAA model was developed at the Air Force Research Laboratory by binning six years of data from the Compact Environment Anomaly Sensor on-board the TSX-5 satellite. A general description of the physics of the SAA will be given, as well as a technical review of the model itself, followed by a description of a typical use case, computing entrance and exit times for a LEO orbit and ways that end-users (e.g. satellite operators) could expand the utility of the model using their own anomaly databases.

• Trajectory Optimization in STK 9
  Patrick Williams, Penn State University
  
  

  As of the release of STK 8.1, users were given the ability to insert their own targeting profiles in STK/Astrogator via a search plugin. These plugins can be used to implement user-defined optimization algorithms (either coded in-house or from an external source) within STK/Astrogator, allowing for optimization of mission parameters and mission segments. In the fall 2009 release of STK 9.1, users will also be able to add and integrate their own variables to STK's internal state vector. This process allows for trajectory optimization through an indirect optimal control method. Both a basic optimization search plugin and optimal control setup will be described, as well as how to use them in coordination to solve the cumbersome optimal control problem.

• Using Root-Finding and Optimization Search Algorithms in Maneuver Planning
  Paul Black, AGI
  
  

  Root-finding and optimization search algorithms play an important role in trajectory design and maneuver planning problems. The algorithms find the times, directions and magnitudes of maneuvers needed to meet mission requirements. In this presentation, several such algorithms are discussed, including the bisection search, Newton-Raphson, differential correction and gradient optimization methods. Examples of using these methods with STK/Astrogator to solve maneuver planning problems are provided.

• Wireless InSite Real-Time® Urban Propagation: Reasonable Fidelity in Real Time
  Gregory Skidmore, Remcom
  
  

  AGI's STK/Communications software is being enhanced to provide EM urban propagation calculations using Remcom's Wireless InSite Real-Time. This talk provides an overview of Wireless InSite Real-Time, which combines optimized ray-tracing techniques developed at Remcom and Wireless InSite's powerful geometry processing capabilities with novel techniques to quickly estimate field levels in an urban environment. The result is a capability to predict the path loss between a given transmitter and receiver pair with calculation time on the order of a millisecond. The discussion covers the suite of real-time models that are included in the calculation engine and describes the general algorithms used in each model. It concludes with a comparison of results between higher-fidelity physics models and the real-time models, along with the computational savings (orders of magnitude) that the real-time models provide over full physics models.

AGI Components

• AGI Components Communications Library
  Trevor Stief, AGI
  
  

  This talk will present best practices for using the AGI Components Communications Library. Learn how to develop software which models the signal links between platforms using the antenna models and propagation effects provided by this library. A comparison with the STK/Communications Specialized Analysis Module will also be provided.

• Building Vehicle Routes with AGI Components' Routing Library
  Richard Page, AGI
  
  

  Discover the functionality, usability and sample code planned for AGI's "Routing Library." This library creates dynamic ground, sea and air vehicle routes for mission planning.

• Developing with Insight3D
  Patrick Cozzi, AGI
  Michael Bartholomew, AGI
  
  

  Learn the major features of this new 3D visualization component, including terrain, imagery, primitives, overlays and camera control. A wide array of code examples, screen shots, demos and performance best practices are also included.

• Leveraging Multi-Core/64-Bit Processors with AGI Components
  Frank Stoner, AGI
  
  

  AGI Components are built to take advantage of the latest processor technologies, such as multi-core processors, which allow multiple computational threads to work toward a problem solution in parallel,and 64-bit processors, which use significantly larger process memory spaces. Learn how the AGI Components team leveraged a Dual Quad Core, 64-bit Windows XP Workstation with 32 GB memory to quickly solve the complex problem of identifying possible collisions between nearly 12,000 Earth-orbiting satellites and debris.

STK/STK Engine

• Developing with the Astrogator 9.0 OM and Scripting Tool
  Paul Black, AGI
  
  

  Uncover the basics of the STK/Astrogator Object Model, including points like stopping conditions and single segment mode. A simple scenario including targeting will be created. Discover the new scripting tool via examples such as having one control map to more than one place, using ST as an initial guess tool and using the ST to augment MCS logic.

• Platform Independence: Developing STK Engine Applications with Java
  Matt Ward, AGI
  
  

  Learn how to utilize the STK Engine from AGI's Java API in various Java application configurations. Specifically, key points/best practices/code samples will be discussed for embedding the Map/Globe/Object Model in AWT/Swing and SWT RCP applications on Windows/Linux/UNIX platforms.

• Real-Time Tracking Technology (RT3) Integration
  Matt Amato, AGI
  
  

  Get your RT3 development feet wet with an overview of RT3 architecture, plug-in points and integration options.

• STK 9 OM Usability Improvements
  Matt Ford, AGI
  
  

  The STK 9 Object Model features usability improvements including code snippets, new automation events and many coarse-grained convenience functions for rapid development. Several code examples demonstrating the new interfaces will be presented.

• STK 9 UI Plugins
  Ed Mackey, AGI
  
  

  Integrators can now create custom workflows for the STK 9 desktop via User Interface (UI) Plugins. Examples will show how you can design toolbars, GUI panels and context menu options that integrate third-party or in-house capabilities inside of STK.

Orbit Determination Tool Kit (ODTK)

• Integrating ODTK & STK with Scripting
  Tom Johnson, AGI
  
  

  Learn from a master Orbit Determination Tool Kit scripter advanced techniques and tricks for manipulating ODTK scenarios and interfacing with STK & STK/Astrogator maneuvers. ODTK 6 scripting improvements will be highlighted. Examples in several scripting languages will be provided.

• A Description of Filters for Minimizing the Time Required for Orbital Conjunction Computations
  Dr. Jim Woodburn, technical director/chief orbital scientist, AGI
  
  

  Identifying potentially dangerous conjunctions is most commonly done by determining periods of time when two objects have an unacceptable risk of collision. Solving this problem for the entire catalog of objects vs. all other catalogued objects quickly illustrates the need for computational acceleration techniques.

  Hoots et al.1 designed a series of three filters through which candidate objects have to pass before a final determination of the close approach distance is made. Two of the filters are purely geometrical and one uses the known properties of the orbital motion of the two objects. These filters serve to "weed out" the majority of the objects in the catalogue and greatly reduce the number of computations needed. After the application of the filters, the trajectories of the remaining candidate objects are sampled to determine the actual close approach periods. The three filters will be referred to as the apogee/perigee filter, the orbit path filter and the time filter. These filters are easy to understand, but in practice they have been shown to be inadequate when implemented as originally described. Additionally, the filters were originally designed for use with a space catalog comprised solely of two line element (TLE) sets. Now that a special perturbations version of the space catalog is being generated, any dependence on TLEs must be eliminated.

  For each of the filters put forth in Hoots et al., we will examine the premise of the filter, demonstrate failure cases and provide details of an improved implementation. The assumptions and potential failure cases for the improved implementations will be identified. Requirements for the use of computational pads will be examined along with the associated impact on computation time. The computational efficiency provided by each filter will be tabulated both independently and in conjunction with other filters. Finally, the reliability of the filtering process will be evaluated using an "all on all" example where results will be generated with and without the use of conjunction filters.

• A New Measure of Nonlinearity for Relative Motion during Close Approach
  Dr. Sergei Tanygin, senior astrodynamics specialist, AGI
  
  

  A new measure of nonlinearity for relative motion during close approach is introduced. It is based on the second order expansion of the two-body differential equation. The measure compares contributions from the first and second order terms and quantifies nonlinearity of the relative motion by the relative significance of the second order term. Given this measure and some nonlinearity threshold, a volume of space around a primary satellite can be defined within which the relative motion of any secondary satellite or a piece of debris can be considered linear.

• Assessing Satellite Conjunctions for the Entire Space Catalog using COTS Multi-core Processor Hardware
  Dr. Vince Coppola, senior astrodynamics specialist, AGI
  
  

  This presentation discusses results for the all-on-all conjunction assessment of ~12,000 objects over both a one-day and five-day analysis period. Two methods for obtaining the state information for the space objects are considered. The first method utilizes analytical propagation of the orbit state from known elements at a given epoch (i.e., using SGP4 with TLEs). Analytical propagation reduces the computer memory footprint of each object at the expense of reduced accuracy of the ephemerides themselves. The second method models the ephemeris of each space object using a table of ephemeris coupled with an interpolation method. The accuracy of the ephemeris can be made quite high using this scheme; however, the memory footprint per object is greatly increased.

  Two different software implementations will be used. The first software implementation is a general purpose COTS 32-bit application which has, as part of its feature set, the ability to perform conjunction analysis between space objects. The second software implementation is a custom application designed specifically to perform conjunction analysis between space objects, but built using a set of COTS software components.

  Performance and accuracy of the determination will be presented using three hardware configurations: a single 32-bit 4Gb RAM dual-core COTS personal computer (~$2.5K); five 32-bit 2Gb RAM dual-core COTS personal computers (each ~$2.5K); and a single 64-bit 32Gb RAM 4-core dual processor COTS personal computer (~$5K). Each will be running on a commonly available Windows operating system.

• Anti-Satellite Engagement Vulnerability
  Dr. Sal Alfano, senior research astrodynamicist, CSSI
  
  

  This presentation discusses several simplifying assumptions that can be made to initially assess the threat from an ASAT interceptor to produce a conservative engagement volume. An initial determination of vulnerability can be made by assuming the interceptor is given all its energy at launch and follows a ballistic trajectory to the target. The resulting trajectory begins at the launcher altitude and follows a simple two-body dynamical path until reaching the target satellite. The mathematical equations for such free-flight representation are explained by Bate in describing ballistic missile trajectories for a spherical, rotating earth. This work modifies their approach because the target is in orbit and the launcher can be located above the earth's surface. The effect of earth rotation is addressed by transforming from the ECEF frame to an Earth-Centered Inertial (ECI) frame.

  An engagement volume relative to the interceptor's launch platform is determined by creating a sufficient family of forward trajectories based on different initial launch azimuths and elevations; this volume is sometimes referred to as a "kill basket." Entry and exit times through this volume define the bounds of satellite vulnerability for a specific launcher and specific type of ASAT missile on an ascending or descending intercept profile. Alternately, a vulnerability region can be represented as a geographical footprint relative to satellite position that encompasses all possible launcher locations for a specific interceptor. This is accomplished by creating a sufficient family of backward trajectories from the target satellite using maximum range equations for ascending or descending intercepts based on the ASAT missile's burnout energy.

  These volumes and footprints are created by simply knowing the interceptor's final ECEF energy and are only approximations due to the aforementioned assumptions. The intercept trajectory time of flight from launch to burnout will be underestimated because the actual powered flight segment takes longer than its ballistic representation. The intercept range from launch to burnout will be overestimated because the actual powered flight covers less ground than its ballistic representation. This causes the preliminary analysis to be conservative, creating an oversized volume or footprint. Because of this, the results are adequate for understanding and visualizing the threat, as well as determining if more detailed analysis is required. The actual missile fly-out profile for a specific engagement would be required to more accurately assess the threat.

• Analysis of the Iridium 33-Cosmos 2251 Collision
  Dr. T.S. Kelso, senior research astrodynamicist, CSSI
  
  

  On 2009 February 10, Iridium 33 - an operational US communications satellite in low-Earth orbit - was struck and destroyed by Cosmos 2251 - a long-defunct Russian communications satellite. To better understand the circumstances of this event and the ramifications for avoiding similar events in the future, this presentation provides a detailed analysis of the predictions leading up to the collision, using various data sources, and looks in detail at the collision, the evolution of the debris clouds, and the long-term implications for satellite operations. The only publicly available system available to satellite operators for screening for close approaches, SOCRATES, did predict this close approach, but it certainly wasn't the closest approach predicted for the week of February 10. In fact, at the time of the collision, SOCRATES ranked this close approach 152 of the 11,428 within 5 km of any payload.

  A detailed breakdown is provided to help understand the limitations of screening for close approaches using the two-line orbital element sets. Information is also provided specifically for the Iridium constellation to provide an understanding of how these limitations affect decision making for satellite operators. Post-event analysis using high-accuracy orbital data sources will be presented to show how that information might have been used to prevent this collision, had it been available and used. Analysis of the collision event, along with the distribution of the debris relative to the original orbits, will be presented to help develop an understanding of the geometry of the collision and the near-term evolution of the resulting debris clouds. Additional analysis will be presented to show the long-term evolution of the debris clouds, including orbital lifetimes, and estimate the increased risk for operations conducted by Iridium and other satellite operators in the low-Earth orbit environment. The final portion of the presentation will look at how collaborative efforts, such as the current Data Center operations supporting SOCRATES-GEO, might be used to reduce the overall risk of similar events in the future.

• Discriminating Threatening Conjunctions with Data Fusion Principles
  Dr. David Finkleman, senior scientist, CSSI
  
  

  The objective of the presentation is to apply information theory and data fusion principles to discriminating the most important satellite conjunctions from thousands of close approaches that occur every day. The significance of predicted conjunctions is now determined from single conjunction assessments based on the most current orbit data. Generally, attention focuses on the few most probable conjunctions at each reporting interval. The hierarchy of probability changes with each assessment. Highest probabilities on previous assessment may be supplanted by currently more likely events. However, the probabilities that caused concern previously generally have not changed, and conjunctions that demanded attention previously and which are yet to come still deserve attention. We will demonstrate conjunction significance assessment techniques that fuse past conjunction reports, information about the conjunction partners, and estimates of the consequences should collision occur. We will show that these techniques would have discerned the Iridium 33 - Cosmos 2251 collision days before it happened. We will also show how these techniques illuminated several important events since the Iridium/Cosmos collision.

  Once a conjunction rises to immediate high probability, we determine how many other conjunctions the most significant collision partner might be exposed to within the assessment period. We then compound the probabilities of all of these estimated events in chronological order. The important measure is how likely the most valuable asset is to collide with anything during the assessment period, not just how likely the single highest probability is. We demonstrate this with a very recent cluster of conjunctions experienced by Cosmos 1818. We assess consequences with trusted fragmentation models and note the distribution of fragment masses and trajectories. We also consider the characteristics of the satellite missions and payloads.

• 2009 LMCO User Group Meeting (valid company login required)
• 2009 NASA User Group Meeting (valid company login required)

• General Users' Conference Photos
• Conjunction Analysis Workshop
• Developer Sessions
• Networking Lunch
• Tech Zone
• Under the Hood
• User Presentations