Perestroika and glasnost in the soviet space programme A personal view

For many years the world-famous Kettering Group of amateur satellite observers have confounded many more ‘official’ organization with their accucary in tracking Soviet space launches. In this article the group's founder, Geoffrey E. Perry, MBE, presents his personal perspective on current developments in the Soviet space programme. The USSR's increased openness about non-sensitive issues is to be welcomed, he concludes, but the Kettering Group has work to do yet.     

Susan: A New Doppler Radionavigation System

SUSAN is a novel electronic Doppler navigation system which can be used with moving vehicles including aircraft, missiles, satellites, and ships. The system uses a technique of time delays and frequency multiplication to determine the rates of change of the Doppler frequency component present on a signal received from a moving vehicle. From this information the range and velocity of the vehicle can be determined with respect to a transmitting station whose position or ephemeris is known.     

Office Information Systems Cost Justification

The purpose of this paper is to present a new methodology for the cost justification of office information systems in engineering environments [1]. The methodology is called the hedonic wage model. It is based on the fact that the allocation of labor resources in an organization tends to conform to certain logical economic criteria. These criteria, along with information on the costs of labor and on how workers spend their time, permit inferences about the organizational values of key activities. The value of an information system can be estimated based on its contribution to the key activities.     

Application of the Concept of Referenced Radio Navigation

This paper discusses referenced radio navigation, the concept whereby monitoring stations at known locations are used to calibrate out systematic errors in a navigation system. This concept is implemented by broadcasting calibration data to the navigating user for application as real-time corrections to the position fixes made by the user's basic navigation equipment. A method is suggested for the automatic transmission and receiver processing of the correction data. Referenced radio navigation overcomes many of the shortcomings generally associated with long-distance navigation systems, and can increase accuracy and repeatability significantly. The concept is particularly applicable to global navigation systems such as OMEGA, in which propagation or synchronization errors can contribute substantially to the system error budget.     

Aircraft flight parameter estimation using acoustical Lloyd'smirror effect

A model is developed for the acoustical Lloyd's mirror effect observed in the output time-frequency distribution of a microphone located near the ground during the transit of a jet aircraft. The feasibility of using this effect for flight parameter estimation is assessed by a simple Cramer-Rao lower bound analysis. The nonlinear least-squares method and the generalized Hough transform method are formulated for flight parameter estimation. The performances of both methods are evaluated and compared using real acoustic data     

SAR imaging of moving targets

A method of forming synthetic aperture radar (SAR) images of moving targets without using any specific knowledge of the target motion is presented. The new method uses a unique processing kernel that involves a one-dimensional interpolation of the deramped phase history which we call keystone formatting. This preprocessing simultaneously eliminates the effects of linear range migration for all moving targets regardless of their unknown velocity. Step two of the moving target imaging technique involves a two-dimensional focusing of the movers to remove residual quadratic range migration errors. The third and last step removes cubic and higher order defocusing terms. This imaging technique is demonstrated using SAR data collected as part of DARPA's Moving Target Exploitation (MTE) program     

Wind Farm Clutter Mitigation in Air Surveillance Radar

Windmills provide a renewable energy resource that could become major components of the power infrastructure in the United States, Europe, and Asia within the next decade. However, collections of windmills, known as wind farms, cause interference in radars that are critical to air defense and air traffic systems. Therefore, to maintain and, perhaps, improve air surveillance, methods that mitigate the inevitable performance degradation seen in radar systems must be proven and implemented to deal with wind farms as they become more prevalent. Herein, the authors discuss recommended techniques for wind farm mitigation, which are based on a UK Royal Air Force-sponsored demonstration on a Watchman radar, conducted at Clatter, South Wales. Specifically, false alarm and false track reductions will be quantified.     

The IBEX Flight Segment

IBEX provides the observations needed for detailed modeling and in-depth understanding of the interstellar interaction (McComas et al. in Physics of the Outer Heliosphere, Third Annual IGPP Conference, pp. 162–181, 2004; Space Sci. Rev., 2009a, this issue). From mission design to launch and acquisition, this goal drove all flight system development. This paper describes the management, design, testing and integration of IBEX’s flight system, which successfully launched from Kwajalein Atoll on October 19, 2008. The payload is supported by a simple, Sun-pointing, spin-stabilized spacecraft with no deployables. The spacecraft bus consists of the following subsystems: attitude control, command and data handling, electrical power, hydrazine propulsion, RF, thermal, and structures. A novel 3-step orbit approach was employed to put IBEX in its highly elliptical, 8-day final orbit using a Solid Rocket Motor, which provided large delta-V after IBEX separated from the Pegasus launch vehicle; an adapter cone, which interfaced between the SRM and Pegasus; Motorized Lightbands, which performed separation from the Pegasus, ejection of the adapter cone, and separation of the spent SRM from the spacecraft; a ShockRing isolation system to lower expected launch loads; and the onboard Hydrazine Propulsion System. After orbit raising, IBEX transitioned from commissioning to nominal operations and science acquisition. At every phase of development, the Systems Engineering and Mission Assurance teams supervised the design, testing and integration of all IBEX flight elements.