Stephen Paul Lake

Design and fabrication progress in BAe's high-complexity resistor-array IR scene projector devices

Developments are described in the design and manufacture of full 512 X 512 infra-red scene projector (IRSP) systems, as well as in a high complexity demonstrator program to realize 1024 X 1024 complexity. Design aspects include choice of drive circuit, the suspended resistor pixel design factors, the choice of busbar configurations, and the optimization of emissivity coatings. Design of the peripheral drive systems for the 512 system is outlined, and progress on manufacture reported. Development plans for the provision of suitable high complexity computer scene generation is outlined.

Performance characteristics of a 256 x 256 suspended resistor infrared scene generator system

A 256 X 256 suspended resistor infrared scene generator system is being constructed. The system consists of a high technology core device which generates the infrared radiation and three conventional technology peripheral subsystems. At the time of writing, measurements have been made of the critical core device component parts, i.e., the transistor drive backplane and the suspended resistor superstructure separately, measurements of the complete integrated system have yet to be completed. Measurements of performance are presented and brief subsystem descriptions are included to aid in understanding of the overall system.

Refinements in practical accuracy factors for resistor-array IR scene projectors

We describe incremental improvements in measurement, understanding and control of sensor-perceived scene accuracy factors for BAe resistor-array IR scene projector devices by means of system and device design, analysis and measurement methodology. Progress has been made in the areas of fill- factor measurement, aliasing effects, dead pixel statistics, image spreading, the design of non-uniformity correction (NUC) systems, busbar robbing, heatsink effects and noise sources.

Practical accuracy factors in resistor-array infrared scene projector systems

This is the second in a series of papers describing an on- going investigation into the detailed performance of our resistor array infra-red scene projector devices and systems. The purpose is to extract understanding and information which will enable validation of simulations involving the systems, and design compromises to be resolved. Following last years conclusions, the importance of Non Uniformity Correction is reinforced and the concept of Local Step Error and its importance is developed and investigated practically. A test methodology is developed, and the first steps in practical measurements are reported.

Developments in the use and design of a suspended resistor IR scene projector technology

This paper describes two aspects of work carried out at British Aerospace on a family of suspended resistor infrared scene generators intended as sources for exercising infrared seeker systems in simulation environments. In the first aspect, a 256 X 256 system has matured and entered service with hardware-in-the-loop (HWIL) simulation facilities. This system, designated TPS4 (for thermal picture synthesizer) has performance suitable for air target tracking studies, and certain aspects of its characteristics in use are described. In the second aspect, research work has been carried out on the extension of the system performance to enable the representation of higher temperature targets, such as are required for countermeasures work. These improved devices are designated TPS5, and aspects of their rationale, design, and evaluation are described. Prototype arrays suitable for eventual systems of complexity 512 X 512 and beyond have been tested.

Developments in the design and performance of IR scene projector devices at BAE Systems

The status of development of resistor-array infra-red scene projector devices at BAE SYSTEMS is that two variants of a 512 X 512 array have each been brought to a second development stage, whilst work on higher complexity arrays is slow but purposeful. In this paper we describe the latest features of the 512 arrays, exhibiting on the one hand high fidelity performance through a ballast-load configuration, and on the other hand very high apparent temperature output, coupled with high speed performance. For higher complexity arrays we describe some of the system philosophy and preliminary design work.

Nonuniformity correction of resistor arrays with a precision projector/sensor mapping method

We present a description of a new non-uniformity correction system for infra-red resistor arrays which has been designed to produce the maximum uniformity of output from neighbor pixels achievable, with a special emphasis on performance at low (ambient) output radiance levels. The system is based on a precision 1:1 mapping between the sensor and projector pixels, and utilizes an all-on approach for projector pixel illumination. The philosophy for system choices is presented, together with analyses and measurements. The system hardware is outlined, and measurements are presented from the system in use showing that at ambient levels, uniformity of better than 100 mK can be achieved between neighbor pixels. This corresponds to a uniformity deviation of some 0.35%.

Update on BAe resistor-array design and development

We describe the status of various aspects of BAe resistor array infra-red scene projector systems for hardware-in-the- loop testing. The aspects covered include subsystem development on current 512 X 512 systems; electronic data handling and driver systems, optical projection collimators, heatsink, cooling and environmental gas control systems. Design aspects are sketched for the progression from existing demonstrator arrays of up to 1024 X 1024 into complete systems.

Characterization of BAe 512x512 resistor array IR scene projection devices

We describe preliminary characterization results from two newly completed types of 512 X 512 IR scene projection system, covering the cardinal performance features. The two systems have been optimized for different applications, one specializing in high radiometric output and speed, the other in radiometric accuracy and low fixed-pattern noise. The devices show improvements over our previous systems not only in complexity, but also in dynamic output, picture dependency performance and non-uniformity correction. Both systems have been built to operate on flight motion simulator tables.

High-fill-factor suspended-resistor IR scene generator: design, fabrication, and preliminary performance

We describe an experimental program of design, fabrication and preliminary performance of an infrared scene generator system designed as a 256 X 256 element electrically heated pixel array. Each pixel consists of a suspended resistor element which has a high area fill factor, being designed as a 3D structure of an electronic drive backplane. Initial performance shows that a practical device can be designed with around 300 degree(s)C temperature range.