While studying the concepts of energy, entropy, and action propagation through the aether, the authors had occasion to review the ideas used by those who founded the age of modern physics. This paper will revisit this era using Sir Edmund Whittaker's treatise, A History of the Theories of Aether and Electricity,1 Max Planck's The Theory of Heat Radiation,2 and Arnold Sommerfeld's Thermodynamics and Statistical Mechanics.3 as primary reference sources.

The alignment of a dual-axes Sun sensor subsystem to, a telescope having a multiple sensor subsystem is described. The Sun sensor consists of two analog and one digital silicon detectors. The analog detectors are shadow mask type operating in the visible spectrum. The detectors are mounted for azimuth and elevation positioning of biaxial gimbOs. The digital detector is a linear diode array that operates at a spectral position of 0.7 micron and is used for elevation positioning. The position signals correspond to relative angles between the Sun sensor and the solar disk. These three detectors are aligned on an Invar structure which is mounted to a Cassegrain telescope. This telescope relays solar radiance to an eight channel detector subsystem operating in the infrared range from 2 to 10 microns. The test technique and results to check the boresight alignment of these two subsystems by scanning the solar disk will be reported. The boresight alignment for both the azimuth and elevation axes of the two detector subsystems is verified using this technique.

The photopolarimeter ISOPHOT is one of the complex instruments on board of ISO. For that purpose integrating detector signal multiplexers, operating at or below 4 K are designed and manufactured. Although at deep cryogenic temperatures Silicon MOS transistors show anomalies in their characteristics, compared to room temperature operation, it will be demonstrated that the requirements of the ISOPHOT mission can be reached. The circuit design options will be discussed. The results of the measured power dissipation, DC transfer function, noise and stability will be compared with the mission requirements. The power dissipation is lower than 300 pw at a readout rate of 9.4 kHz, the read noise is limited to 200 electrons and the Noise Equivalent Power in combination with Si:Ga detectors is 2.E-17 W√Hz.

This paper describes a technique for conducting environmental tests of multi-spectral sensor systems. The method combines the advantages of field tests and the economics of laboratory experiments to provide an accurate test bed for predicting system performance for a wide range of temperatures. It consists of placing the system inside a carefully controlled temperature chamber while the sensors observe real-world targets in the field. The major difficulty in this type of test, i.e. the problem of finding a chamber window which will remain functional over the desired temperature and wavelength range, has been overcome. The solution, which was shown to work quite well, is to utilize a Nitrogen gas window to prevent fogging at cold temperatures. The line-of-sight (LOS) deviations introduced by this window are extremely small at all wavelengths. This paper also describes the insulated mounted scheme, the temperature controls, and the chamber design. Test data establishing the optical performance of the thermal system under a wide range of temperatures (-45C to 70C) and wavelengths (0.4 to 11 micrometers) have demonstrated that this method is technically superior to field testing, at a much lower cost.

An absolute reflectometer for the 0.8 - 5.5 microns region is described, and reflectance spectra for some diffuse metallic surfaces are given. Some of the spectra show a dip of 5-7% in the reflectance values of the surfaces in the 3.0 - 3.5 microns region. Possible causes for the observed dips are discussed.

This paper describes a study made on several mirror coatings for near and far infrared applications at room and cryogenic temperatures. Three materials (Al, Ag and Au) have been tested at two angles of incidence. Absolute measurements at 10.6 μm were obtained with a power stabilized CO2 laser. Bidirectional reflectance distribution function (BRDF) and total integrated scattering (TIS) are given for three wave-lengths at 0° and 45° angles of incidence.

A variety of spatial filters have been previously proposed as detection filters for automated target acquisition. One class of filters, namely the matched filter, is designed for maximimum signal to noise response at true target locations. The filter design is a function of target dimensions and intensity distributions, and of the corresponding background spectrum. The filter sensitivity to target dimensions may be overcome by adapting the filter's dimensions to the incoming image signal, or by the economical use of (at least) two filters, designed separately for small and large targets. The robustness of the Difference-of-Boxes (DOB) filter is established for a class of targets having smooth, 2nd order intensity distributions, in the presence of both white noise and cluttered backgrounds.

Many industrial blackbody furnaces are nonisothermal cavities. It is obvious that the calibrating errors of infrared(IR) thermometers are caused by those nonisothermal blackbody furnaces. In this paper, a narrow-waveband IR thermometer(Si-cell detector) is calibrated and researched by means of experiment and theoretical calculation. The law of the calibrating errors is found. According to the theory of the effective temperature of a blackbody cavity, the calibrating errors are calculated. The calculating results are basically consistent with the experiment results.

This paper compares the status of millimeter wave (MMW) technology as applied to military systems to the status as described in a paper published 10 years ago on the same subject. Brief descriptions of MMW systems are given, even though none have yet been deployed. An attempt is made to explain why infrared systems have proliferated while MMW systems are constantly under development.

Several sources of thermal band infrared data and their use for statistical scene analysis are discussed. Special calibration experiments for the Daedalus Thematic Mapper Simulator and the LANDSAT Thematic Mapper are described which show the accuracy of both sensors to be within 2 to 3 degrees Celsius. A statistical background data base developed for many different backgrounds is presented.

The past ten years has seen progress in the understanding of the ultraviolet background of the earth's atmosphere. These airglow, auroral, and scattering emission sources set limits on the usefulness of UV for space observations. They also, however, enable several types of passive remote sensing; such as, electron density profiles, neutral density and composition, and auroral location and strength. The paper describes our measurements and data analysis in these areas. UV imaging of the aurora has been achieved by four experiments, and these are briefly reviewed. UV imaging has opened up a new way to study solar-terrestrial relationships.

The quality of radiometric models for generation of synthetic scenes is difficult to evaluate because of the cost and complexity of experimental data collection. In addition, the number of variables to be controlled or monitored is prohibitive. This paper suggests the use of a cold hohlraum and calibrated LWIR imaging systems as a method for testing certain components of radiometric models. The model tested includes self-radiance from the source, reflected background radiance, specularly reflected sky radiance, diffuse sky radiance, diffuse and hemispheric angular emissivity, atmospheric transmission, path radiance, sensor spectral response functions, sensor instantaneous field-of-view, and various types of sensor noise. The laboratory measurements are able to evaluate those aspects of the radiometric synthetic imaging model used in generation of the radiance field toward the sensor as a function of view angle. The final modeled image can be compared to the laboratory observed radiance field propagated to the sensor. This method allows for evaluation of the model's ability to effectively account for changes in emissivity with look angle, the effects of changing "sky temperature," changing emissivity of background surfaces (e.g. water roughness in naval scenes), and the interplay of target and backgrounds in the formation of infrared "halos." Both image comparisons for phenomenological assessment and quantitative radiometric comparisons are included in the discussion.

Initial evaluation of the performance characteristics of a 1 x 128 dual multiplexed MWIR FPA assembly are discussed. The CMOS multiplexer individually buffers the input to each element of the photovoltaic indium antimonide (InSb) detector array. Individual charge amplifiers allow signal integration on an integration capacitor located within each channel of the multiplexer. Two different capacitance values can be digitally selected to allow high sensitivity in low incident background or high storage capacity for high background applications. A description of the multiplexer architecture is presented. In the high sensitivity mode of operation, the detector charge storage capacity is 3.5 x 10⁶ electrons with an electronic sensitivity of 0.6 μV/electron. A larger storage capacity of 3.5 x 10⁷ electrons can be selected in a lower sensitivity mode. The InSb detectors have spectral response in the 1 to 5.5 μm region. The detectors operate at near zero bias so dark current non-uniformities are minimized and operating temperatures of 100 to 120 degrees Kelvin are practical. Performance characteristics discussed will include D*, signal linearity, read noise, responsivity, and quantum efficiency.

Preliminary evaluation of the performance characteristics of a new two-dimensional multiplexed MWIR focal plane array assembly is discussed. The CMOS BDRO multiplexer individually buffers each detector in the 64 x 64 element array. This multiplexer was designed with an emphasis on low-background applications and results will be reported accordingly. The detector is an array of photovoltaic indium antimonide (InSb) diodes bump bonded, using indium columns, to the silicon multiplexer and is thinned for back-side illumination. The detector element size is 87 x 87 microns on 100 micron centers. Charge storage capacity is approximately 4 x 106 electrons. The InSb array substrate is thinned to approximately 15 microns and spectrally responsive in the 1 to 5.5 μm region. Electro-optical test results include the performance parameters: quantum efficiency, signal linearity, and dark current. IR images will be presented to illustrate initial array performance.

Infrared 14-16 micron band earth horizon radiance measurements have been made by the Static Earth Sensor on the IRS-1A remote sensing spacecraft launched in March, 1988. The satellite carries a 4-head Static Earth Sensor detecting radiance from the earth horizon in the Carbon Dioxide emission band at 15 microns. Four separate Germanium lenses with thermopile detectors and processing electronics are used. The output is converted into radiance in Wm-2sr-1. This is the radiance measured by the detectors and emitted from the atmosphere at about 30-40 km altitude over the Sensor crossing points. The Sensor outputs are used to derive the roll and pitch errors of the spacecraft.

MITSUBISHI THERMAL IMAGER model IR-5120A is high resolution and high sensitivity infrared television imaging system. It was exhibited in SPIE'S 1988 Technical Symposium on OPTICS, ELECTRO-OPTICS, and SENSORS, held at April 1988 Orlando, and acquired interest of many attendants of the symposium for it's high performance. The detector is a Platinium Silicide Charge Sweep Device (CSD) array containing more than 260,000 individual pixels manufactured by Mitsubishi Electric Co. The IR-5120A consists of a Camera Head. containing the CSD, a stirling cycle cooler and support electronics, and a Camera Control Unit containing the pixel fixed pattern noise corrector, video controllor, cooler driver and support power supplies. The stirling cycle cooler built into the Camera Head is used for keeping CSD temperature of approx. 80K with the features such as light weight, long life of more than 2000 hours and low acoustical noise. This paper describes an improved Thermal Imager, with more light weight, compact size and higher performance, and it's design philosophy, characteristics and field image.

Silicides used commonly for Schottky barrier infrared (IR) imaging arrays, are those of platinum and palladium. Recently good results have also been reported for IR sensitive composed Pt-Ir silicides. The uniformity of the response over large detector arrays and the VLSI fabrication compatibility are their main advantages, as compared to non Schottky type detectors. This paper presents theoretical as well as experimental data on the cobalt silicide as used in Schottky detectors for the short wavelength IR (SWIR) band. The big advantage of a CoSi2 detector, over the conventionally used silicides, is its higher operating temperature allowing passive cooling in space remote sensing applications.

Recent Advances in staring infrared focal plane technology make possible the design of advanced infrared imaging systems whose performance can meet or exceed that of classic FLIR systems. The design considerations and performance evaluation relating to staring systems is similar to, but differs from those of the classic FLIR system. This paper discusses the general concepts and design philosophy directed at the development of a fieldable high performance staring infrared imaging system. Examples of system evaluation techniques for fieldable systems are discussed.

A series of wind tunnel experiments were conducted as part of a systematic study for evaluation of infrared thermography as a viable non-intrusive thermal measurement technique for aerodynamic applications. The experiments consisted of obtaining steady-state surface temperature and convective heat transfer rates for a uniformly heated cylinder in transverse flow with a Reynolds number range of 46,000 to 250,000. The calculated convective heat transfer rates were in general agreement with classical data. Furthermore, IR thermography provided valuable real-time fluid dynamic information such as visualization of flow separation, transition and vortices.

A continuous programme of development of the TICM II imager has allowed significant improvements in system performance to be realised. Some of these developments are described, concentrating in particular on modifications to the SPRITE detector and associated system components which hive led to substantial increases in the thermal sensitivity and spatial resolution.

The philosophy of the U.K. Thermal Imaging Common Module programme, TICM, envisaged from the outset that future requirements that could not be met by using the basic module suite would be met by developing "stretched" or enhanced versions of the modules. The design of the system took that into account. The philosophy has been completely justified by the success of the many stretch programmes. In the ten years since the first class II imager was produced, the inventory of enhanced, "stretched" modules has grown to include higher sensitivity, improved spatial resolution, alternative line standards, reduced size, multi spectral variants and latterly an all digital version of the imager. This paper reviews those and other related stretch programmes, and includes a brief review of the UK Common Module Programme.

A complete simulation system has been developed to perform motion table testing of IR imaging seekers. The system consists of an IR projector, an imaging system composed of a computer and a real-time graphics processor, and an integrated IR signature modeling system. The simulation system can perform both seeker-in-the-loop and open-loop simulation. The IR projector, which uses a liquid crystal light valve (LCLV), is driven by a conventional CRT and projects images in the 8-12 micron range. The off-line IR signature modeling software is completely integrated with the simulation system. It consists of (1) a geometric target modeler, (2) an interactive geometric scene editor, (3) a thermal model, and (4) an atmospheric attenuation model based on LOWTRAN 6.

In its current form, the NVL model does not adequately predict the laboratory measured minimum resolvable temperature (MRT) values at low or high spatial frequencies. The differences between the measured and the predicted values are caused by inappropriate modeling of the eye, tremendous variability in observers, and ill-defined data analysis methodology. In the usual laboratory procedure, the observer is allowed to move his head. This, in effect, removes the eye's response from the model because by adjusting his viewing distance, the observer appears to achieve equal detection capability at all spatial frequencies. Threshold detection can vary significantly from observer to observer and from session to session. For a large population, the detection process can be described by a log-normal distribution, and the mean MRT is the geometric average of the individual MRT responses. Geometrically averaged MRT data from three different common module-based, digital scan-converted forward-looking infrared (FLIR) systems have been compared to theoretical values. The modulation transfer function (MTF) of each FLIR was calculated using the same equations found in the NVL model. The theoretical MRT curves fit the experimental MRT data when MRT = 0.7*NEDT/MTF. For one FLIR system, the MTF was experimentally obtained by taking the Fourier transform of a slit response. The resultant MTF matched theory extremely well and therefore an objective MRT test was established.

Failure and yield analysis capabilities were developed for focal plane array (FPA) readout devices probe tested at wafer level instead of merely performing production rate testing and cataloging data. Innovative test strategies have been combined with software techniques to provide tools which accomplish these analyses while maintaining high throughput in test. This approach has been beneficial and valuable in saving test time when searching for hardware faults, investigating design susceptibilities, revealing foundry process variations from wafer to wafer and/or lot to lot, and creating a yield model for the parts tested. Testing of readout devices has historically been viewed as a major obstacle in high volume production of reliable components for focal plane systems. Thorough testing in a high throughput automated wafer probe environment may be achieved, but often at the expense of real-time analysis of failures and yield factors. Production testing has been established with these goals in mind rather than as an afterthought. This enables one to identify failure mechanisms as they occur in order to reduce yield loss and unnecessary test time. In addition to performing requisite data base management, routines have been created to re-sort data and reevaluate yield through varying performance parameter limits, to track and map failure mechanisms as they are encountered, to examine acquired data as a function of limits, and to provide yield information for feedback response to foundry processing. Ideas for aiding operators in recognizing and diagnosing possible test set hardware problems (as opposed to on-chip failures) have also been implemented.

Significant advances have been made in recent years in the development of photodetector arrays for optical processing applications. The dynamic range of optical processors has been until now limited mainly by photodetector arrays. Detector performance issues and developments in detector arrays for optical processing are reviewed with emphasis on time-integrating arrays. A first report of a 60 dB dynamic range photodetector array developed at Loral Fairchild Imaging Sensors is also presented.

A 1024x1 element CCD photodetector array is being developed for optical processing applications that require high frame rates and wide dynamic range. Initial characterization of the photodetector array has shown a 60 dB dynamic range in optical power. The detector output circuits support a total output data rate greater than 256 MHz.

The need for increased resolution and sensitivity in tactical IR systems applications has provided the impetus for the development of high performance second generation staring focal plane array technology. Previously, the availability of these focal plane array components has been limited and the costs associated with delivery of useful hardware have been high. Utilizing proven InSb detector technology and foundry silicon CMOS processes, a high performance, affordable hybrid focal plane array and support electronics system has been developed, with the cost being less than $3 per pixel. The 128 x 128 array of photovoltaic InSb detectors on 50μm centers is interfaced with the silicon readout by aligning and cold welding indium bumps on each detector with the corresponding indium bump on the silicon readout. The detector is then thinned so that it can be illuminated through the backside. The 128 x 128 channel signal processing integrated circuit performs the function of interfacing with the detectors, integrating the detector current, and multiplexing the the signals. It is fabricated using a standard double poly, single metal, p-well CMOS process. The detector elements achieve a high quantum efficiency response from less than 1 µm to greater than 5 μm with an optical fill factor of 90%. The hybrid focal plane array can operate to a maximum frame rate of 1,000 Hz. D* values at 1.7 x 10¹⁴ ph/cm2/sec illumination conditions approach the BLIP value of 9.4 x 10¹¹ cm√Hz/Watt with a capacity of 4 x 10⁷ carriers and a dynamic range of greater than 50,000. The devices operate with only 3 biases and 3 clocks.

The staring infrared focal plane arrays used by Boeing in some applications have large numbers of pixels that are unusable due to variations in detector sensitivity. Values for these defective pixels may be estimated from the neighborhood of surrounding pixels. A linear model of an image is used to determine an RMS error associated with each kind of defect compensation. The RMS error was minimized by median filtering; however, averaging nondefective neighboring pixels and substituting one neighboring pixel at random also produced low errors. Simulation results verifying the study are also presented.

A significant improvement in performance of classical ammunition has become possible by using intelligent fuzes. For short target distance applications the use of Single or Dual Mode IR-Sensors has become state of the art. Excessive requirements to both axial and radial g-load arise from the fact that the sensor, normally positioned excentrically relative to shells rotating axis, has to withstand the cannon launch. High requirements on temperature stability, microphonic noise insensitivity and cross talk are essential for high sensor performance. The response has to be stable over an extended temperature range from -46 degrees C to +63 degrees C. Insensitivity against microphony prevents mechanical vibration induced reduction of sensor signal noise ratio, and low detector element cross talk guarantees high spatial resolution and therefore target classification. In addition, by means of a 20-year wooden round concept, there is a strong requirement for long-term stability. The choice of detector material and operation temperature is essentially determined by cost effectivness. All the requirements mentioned above can be met with different results depending on different detector materials. The usability of some detector materials for intelligent ammunition application has been investigated comparatively by theory and experiments. In a feasibility study different pyroelectrics, thermic detectors, as well as the photonic detectors (thermoelectrically cooled photo conductors), lead sulfide (PbSe) and mercury cadmium telluride (MCT), have been compared.

This paper describes new alloy heterojunction detectors of In.8Ga.2As/InAs.56p.4 which can detect light between 1.7 and 2.6 μm with 50% quantum efficiency and 5 mA/cm2 dark current (-1V) density at room temperature. Wafer probe data showed that over 50 good contiguous 100 μm diameter devices (spaced 400 um) could be made on a 25 x 30 mm wafer with overall yield above 93%. The ability to operate under -1V reverse bias makes these devices ideally compatible with existing commercial multiplexer readouts.

The quantum efficiency distribution function of a detector has a direct influence on the performance and imaging quanlity of a CO2 laser heterodyne detection system. This paper gives out regularization theory to calculate the discrete point quantum efficiency of a detector and method which applies twice splines function to draft quantum efficiency distribution function. Two stablized-frequency CO2 laser and a singal processing system are used to test the quantum effiency distribution function of a photo-voltage HgCdTe detector. The result shows that the quantum efficiency in each point of the detector is uneven. The maximum is twice the minimum. Simple analysis is given to the cause of uneven distribution.

Infrared detectors, two-dimentional arrays, optical components, infrared systems and their applications in civilian, industrial and satellite fields have been extensively studied in various universities, national and company laboratories, which are mainly distributed in the middle part of the mainland in Japan. Among these, only recent unique studies are briefly introduced on the following items, i.e. infrared detector, two-dimentional array, system in satellite and laser diode.

Magnesium fluoride(MgF2) and Magnesium aluminate spinel(MgA1204) ceramics for 3-5 micron IR transmission have been developed by a powder processing technique. Their optical, physical, mechanical, and thermal properties have been measured and compared with each other. The transmittance and flexural strength related with microstructures are studied.

This paper describes the research and development results of the precision horizon-crossing indicator for synchronous orbit (PHIS) suitable for the attitude control of a three-axis stabilized satellite operating at transfer and geosynchronous altitude. The bread-board model (BBM) for Engineering Test Satellite-VI(ETS-VI) to be launched in Summer 1992 by NASDA JAPAN was designed, fabricated and evaluated. The evaluation test results of PHIS/BBM show the excellent earth-pointing performance with respect to its on-orbit operation. And also the environmental and reliability tests have been successfully done for the sensor critical component parts. It is believed that this earth sensor will be one of the most relible and high-accuracy instrument after the 1990's.

This paper describes an online measurement system to detect dew point and CO gas concentration simultaneously in a high temperature furnace using infrared absorption. The measurement system has been successfully applied to the in-situ measurement of the chemical reaction between steel sheet surface and water vapor in the continuous annealing furnace of steel production line.

Infrared radiation heating is becoming widely applied to drying processes of wet industrial materials and to heating processes for food-stuff containing water etc. Thus a growing importance is attributed to clarify the exactpenetration depth of IR radiation into water from heating engineering view point. Many IR transmittance data on water film have been published by various authors. All of them as far as the author knows, however, failed to indicate the detailed optical data of the two window plates used to fix water film thickness. Accordingly the exact penetration depth (or inverse of Lambert absorption coefficient) into water cannot be known, since multi-reflection takes place within bounded water and window plates too, thus affecting the transmittance value to be measured. Moreover in the measurement of very thin water film, there takes place often an interference between forward going electro-magnetic wave and successively reflected backward one. This too affects the measurement particularly in IR region of higher transmittance. Messrs. Robertson & Williams tackled with the captioned theme in the early years, and indicated, in their report"; difficulty to remove the unfavorable effects introduced by window plates in view of finding Lambert coeff. of water. The difficulty had been experienced those days by many authors. Robertson & Williams elaborated a special precise absorption cell with window plates of either CaF2 or KRS-5, and succeeded in giving fairly good Lambert coeff.∝ for 2.33 - 33.3 micro-meter wavelength region. They seemed to have paid enough experimental consideration and made some corrections on the inevitable interference effect, but not enough on the multi-reflection effect. Accordingly their derived formula for giving∝ was not fully theoretically correct, since taking ratio of the two transmittance values with different water thickness did not cancel out all of the window plate effect. The author has carefully taken into consideration the above two effects in his analysis and measurement. He first established analytical formulae comprizing multi-reflection effect under condition with no interference, and second rejected to employ measured transmittance data seemingly under interference state, thus has succeeded in giving the exact penetration depth for 0.9 - 25. micro-meter wave with normal-incidence to free water surface at room temperature(25 ± 5°C). Conversely, taking advantage of the mentioned unfavorable interference, he has also succeeded in giving water refraction-index spectrum covering 0.9 - 2.5 micro-meter region. The same spectrum for 2.5 - 25. micro-meter is also given in the text, by using a special reflectance measurement, though the latter being approximate value. The above water refraction-index spectra are, depending on wavelength region, in good or poor agreement with the corresponding table data which was compiled by Messrs. Hale & Querry in early years from those days published date The spectrum data obtained by himself was employed in later calculation to find 0C.

We are proposing current readout for infrared charge coupled devices (IRCCDs) which can operate at higher temperatures. Feedback direct injection (FDI) consists of a simple amplifier of gain, A<1, connected to a photodiode and a conventional direct injection (DI) circuit. The amplifier feeds the source voltage of an input field-effect transistor back to the photodiode, making the diode's resistance effectively 1/(1-A) times larger. This improves conventional direct injection current readout efficiency. FDI was used in a medium-wavelength IRCCD operating at a high temperature. We made a 64-element HgCdTe linear IRCCD using FDI. The device operates at 195 K with an NETD of 0.5 K.

For astronomical observation in space, we have developed a JFET amplified InSb infrared detector array which can be operated at liquid helium temperature. This detector array uses 24- channel InSb photodiodes, 1 mm x 0.5 mm per element, having low junction capacitance for reducing noise. The JFET amplifier circuit is designed as a hybrid IC containing a 24-channel charge integration amplifier (CIA) array. Since the JFET amplifier circuit cannot operate at liquid helium temperature, it is suspended from the frame using aramid wires and warmed up to about 70 K by a built-in heater. We have evaluated this JFET amplified InSb infrared detector array and obtained good results with readout noise of about 100e . It was confirmed that this noise level is low enough for use in astronomical observation in space.

A CO2 laser for an optically pumped CH OHlaser is stabilized on the center of the CH3OH absorption line y using a photo-acoustic spectroscopy. The frequency stability is measured by referring to a CO2 laser which is stabilized by Freed-Javan method. The stability of the pump laser is obtained to be Jy(t) = 3.0 x 10^-9 x t^{-1 /2} ( is , 1:c100s ) in the terms of the square root of Allan variance. The offset frequency between the CO2 laser line center and the CH3OH absorption line center is also obtained from the beat frequency to be 24.8± 0.1 MHz.

The project of a PLANETENTELESKOP (telescope for planetary observations), a German space project, is introduced briefly. The pointing measurement system of this proposed spacecraft is very ambitious. Requirements derived from the system ask for available CCD and CID detector arrays to be operated in unusual modes. Changes to readout structures are proposed to facilitate such operational modes. The resulting devices could provide problem solutions to a variety of image tracking applications.

This paper describes a study made on five black paints for visible and infrared applications at room and cryogenic temperatures. This work was undertaken for the Infrared Space Observatory, a space optical project under study, planned for 1993. Reflectivity measurements have been performed in the spectral range 0.4 μm - 500 μm at 300 K and 7 K; variations with the angle of incidence are examined at five wave-lengths. Bidirectional reflectance distribution function measurements were obtained with a He-Ne laser. Adhesion and thermo-optical characteristics were studied before and after several thermal cycles (300 K to 4 K).

The Thermal Infrared Profiling Spectrometer (TIPS) is an airborne/spaceborne sensor concept developed at DLR-Institute for Optoelectronics for scientific observations in remote sensing of the earth surface. The patented spectrometer design is based on a fast scanning Fourier spectrometer (FSM) using a rotating retroreflector to achieve the appropriate path alteration thus avoiding the usual linear movement of one of the mirrors in an conventional Michelson interferometer. The spectral band covers the 3 - 13 μm band with a spectral resolution of 5 cm-1 (50 nm at 10 μm). The measured signal is an interferogramm, derived quantities are spectral emissivity, spectral radiance and surface temperature. The optical system consists of an aperture filling plane tilting mirror to provide off-nadir observation and calibration mode. The collecting mirror focal length and the detector area yields an instantaneous field of view (ifov) of 1.2 mrad, noise equivalent temperature resolution of 0.04K (300K), and a noise equivalent change in emissivity Δεof 6 x 10^-4. Calibration is performed by two aperture filling area blackbodies at two different temperatures. An extensive simulation of signal/noise performance of the TIPS has been evaluated by means of the simulation programm SENSAT9, developed by DI.R. This simulation comprises the sensor performance, typical variations of atmospheric conditions and selected spectra from ground surfaces. Results of this simulation are discussed and a description of the sensor is presented.

In the field of infrared spectroradiometry there are several systems available, of which a large majority is intended for measurements on relatively stable radiation sources. Such type of equipment is perfectly suitable for the task of determining spectral radiometric characteristics (emissivity; transmission and reflection coefficients) of specific material samples in a laboratory. Their utility, however, becomes limited when used to analyze rapid events especially out in the field, due to the equipments' (low) speed of acquisition and mechanical overall design.

A computer code, called SENTRAN, which automates process of LOWTRAN-6 analysis by providing various capabilities has been developed. The capabilities include; fail-safe interactive input session, automatic generation of LOWTRAN-6 input deck sets with perturbed values for multiple input parameters, autonomous post-processing of TAPE7 outputs including data extraction and partial derivative evaluation, and graphical representation of the outputs in both 2D and 3D formats. SENTRAN is so versatile that it can provide extremely fast turn-around time for any LOWTRAN-6 analysis.

An imaging spectrometer and associated data processor has been developed which, when fully implemented, will provide a wide (0.4 to 11 micrometer) spectral region coverage with very narrow (hyperspectral) image acquisition capability. The instrument has a field of view of just less than one degree and a pixel IFOV of 27 microradians in the visible - near infrared. The spectral sample dimension is 0.002 micrometers in the visible - near infrared. The instrument is described and the first field test of the short wavelength (0.4 to 2 micrometer) breadboard on the Navy Long Jump III measurement program is reviewed.

Several optical configurations were investigated for acquisition, tracking, and pointing (ATP) systems. These configurations were to be employed for ATPing targets that were to be interrogated by neutral particle beams (NPBs). NPBs delineate real targets from replica or false targets. This particular optical design investigation was for the NPB Concepts and Requirements Definitions Study (CARDS). The proposed NPB CARDS ATP consisted "of a coarse and a precision-passive IR acquisition and tracking sensor coupled to a precision-active UV tracker that referenced boresight, range, and target motion to an NPB-pointing control system."1

In order to model the fluctuations of the order of 5 km in the locator tangent height due to seasonal-latitudinal variations in stratospheric temperature, for improved accuracy in attitude determination from horizon sensors, a study was carried out on the dependence of 50% and 66% locator tangent height on the slope of the horizon radiance profile. A monotonic, second-order relationship was observed between the 66% locator tangent height and the slope of the horizon radiance profile.