bluuebunny/crossref_metadata_2025 huggingface dataset:
ATM Objectives and Requirements For Next-Generation Networks
Authors: Eng Kai Y.
Published: February 2023

Worldwide activities on ATM (Asynchronous Transfer Mode) have been intensifying with rapidly evolving standards (CCITT and ATM Forum) [1,2]. Applications include multimedia services, high-speed LAN's, central-office switches and high-speed digital crossconnects. Potential large-scale network conversion into ATM is being considered and debated within various research and development communities. The push for deploying ATM to upgrade the existing network infrastructure has sometimes been compared to the "analog-to-digital revolution". The primary incentive to do so stems almost entirely from its service flexibility. Here, we discuss various aspects of ATM networking, emphasizing the transport objectives and requirements for next-generation networks. We will begin with the basic notions of ATM networking and then shift to a specific example of a VP (Virtual Path) transport network using an integrated ATM Crossconnect as a key network element.
Transition from Optical Interconnections to Optical Computing
Authors: Williamson Richard C.
Published: February 2023

Optical interconnections will be a foot in the door to the next generation of computer systems and provide an evolutionary path toward the use of optics in finer scales.
Applications of Smart Pixels
Authors: Cloonan Thomas J.
Published: February 2023

Summary not available at time of printing.
Smart Pixel Based Viterbi Decoder
Authors: Haney Michael W. , Christensen Marc P.
Published: February 2023

As voice and data communications networks proliferate, they face ever increasing demands for reliability, portability, and bandwidth. In many applications, the transmitted power is limited by practical considerations. Examples include satellite, cellular, and undersea long haul fiber communications systems. In these applications Forward Error Correction (FEC) techniques may be used to achieve reliable communications within the constrained power. FEC techniques are ultimately limited in their performance by the conflicting requirements of high speed, high computational complexity, and low size and power consumption. VLSI implementations of the elegant and powerful Viterbi convolutional decoding algorithm (VA) [1], which uses a recursive parallel search computation, are limited by the massive intra- and inter-chip communications requirements between nodes of the search graph. This constraint limits the number of states (nodes of the VA graph), for high-speed applications, and hence the overall performance of the VA. Current high speed single chip VLSI implementations are limited to a convolutional constraint length of about 7 and therefore require 27=128 processing nodes. Incrementing the constraint length by one provides nearly an order of magnitude improvement in BER [2], but requires twice as many computational and communications resources -- beyond the capabilities of a single chip. This size constraint limits single chip VLSI implementations to a coding gain of ~7dB. Strong motivation exists for using longer constraint length codes, requiring several decoding ICs. A multi-chip VLSI VA implementation is impractical for high speed applications due to the inter-chip communications bottleneck. The approach discussed in this paper overcomes this limitation by employing free-space optical interconnects to provide the required inter-chip connection, while maintaining on-chip speeds between chips.
Cost-Performance Tradeoffs in Optical Interconnects
Authors: Stirk Charles W.
Published: February 2023

To compare monolithic and hybrid optoelectronic technology to electronics for interconnects, this paper considers systems with the same manufacturing cost. For a given cost system, we calculate the performance advantage that makes chip-to-chip optical interconnects competitive with electronic wire bonds and solder bumps. Adjusting the number of I/O connectors by the ratio of the technology defect densities forces the system costs to be identical. Balanced system design principles and present defect densities farther restrict hybrid optoelectronics to a logic/connector ratio of 104 and monolithic integration to a ratio of ten.
Challenges and Prospects for Multi-chip Microlens Imprints on front-side illuminated SPAD Imagers
Authors: Bruschini Claudio , ANTOLOVIC IVAN , Zanella Frédéric , Ulku Arin , Lindner Scott , Kalyanov Alexander , Milanese Tommaso , Bernasconi Ermanno , Pesic Vladimir , Charbon Edoardo
Published: February 2023

The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. The fill factor loss can however be recovered by employing microlenses, whereby the challenges specific to SPAD arrays are represented by large pixel pitch (> 10 µm), low native fill factor (as low as ~10%), and large size (up to 10 mm). In this work we report on the implementation of refractive microlenses by means of photoresist masters, used to fabricate molds for imprints of UV curable hybrid polymers deposited on SPAD arrays. Replications were successfully carried out for the first time at wafer reticle level on different designs in the same technology and on single large SPAD arrays with very thin residual layers (~10 µm), as needed for better efficiency at higher numerical aperture (NA > 0.25). In general, concentration factors within 15-20% of the theoretical maximum were obtained for the smaller arrays achieving an effective fill factor of 75.6-83.2%. A concentration factor up to 4.2 was measured on large arrays with a pitch of 16.38 m and a native fill factor of 10.5%, whereas improved simulation tools could give a better estimate of the actual concentration factor. Spectral measurements were also carried out, resulting in good and uniform transmission in the visible and NIR.
Lidar Techniques for Remote Sensing of Atmospheric Temperature and Pressure
Authors: Gardner Chester S.
Published: February 2023

A variety of lidar techniques based upon differential absorption, multi-color laser altimetry, resonance-fluorescence and Raman scattering have been developed to measure atmospheric pressure and temperature in the troposphere, stratosphere and mesosphere. The underlying principles for these techniques are reviewed and experimental results are discussed.
El Chichon: Lidar and Satellite Measurements Versus Time and Latitude
Authors: McCormick M. P.
Published: February 2023

The March-April 1982 eruptions of El Chichon produced the largest perturbation to the stratospheric aerosol since at least the 1963 eruption of Agung, and possibly the largest in the last 70 years. Its presence was soon detected by lidars in Hawaii and Japan as the upper portion of the cloud was driven by easterlies and began to immediately impact various remote sensors, producing artifacts in their retrievals. This stratospheric cloud was optically thick enough so that GOES could track it during an entire 3-week circuit of the Earth, At the same time material below about 20 km moved to the east-northeast. In addition, the clouds began spreading meridionally. The bulk of the material below about 20 km moved slowly toward the poles with portions arriving at the Arctic in late April. The material above 20 km contained most of the mass and was primarily confined to the northern Tropics (0° to 30°N) for about the first 6 months after the eruption. In late June and early July, portions of the upper cloud, which was peaked at about 26 km at that time, were detected at Langley (37°N).
Laser Radar System Theory*
Authors: Shapiro Jeffrey H.
Published: February 2023

Coherent laser radars represent a true translation to the optical frequency band of conventional microwave radar concepts. Moreover, the emerging technology of compact CO2 laser radars may be capable of resolving targets in any combination of the modalities of space, angle, range, and velocity. As a result, the development of laser radar system theory as an analytic tool for the design and performance evaluation of such systems must function on a variety of levels. In this paper, three of these levels will be reviewed.
Very Fine Scale Resolution Water Vapor Profiles Acquired by Solar Blind Raman Lidar
Authors: Cooney John A. , Petrie K. , Salik A.
Published: February 2023

Experimental measurements obtained by use of a Solar Blind Raman Lidar (SBRL) involving atmospheric water vapor profiles are reported. The novel findings of this measurement program turn primarily around the very high resolution (5.0m) of the water vapor profiles.
Laboratory Studies of the Infrared Spectra of Atmospheric Species
Authors: Maki Arthur G. , Pine Alan S. , Wells Joseph S. , Jennings Don A. , Fayt Andre , Goldman Aaron
Published: February 2023

We are involved in making laboratory measurements that will provide data useful for remote sensing applications with particular emphasis on upper atmospheric species such as HNO3, NO, N2O, OCS, and O3. In the following sections we describe the results of recent new measurements on HNO3, NO, and N2O.
Remote Sensing of Atmospheric Winds
Authors: Hays Paul B.
Published: February 2023

The technique for measuring atmospheric winds from the Upper Atmosphere Research Satellite (UARS) is discussed. Stress is placed on the use of absorption features in the spectrum of scattered sunlight to measure the motion of the atmosphere by doppler techniques. Instrumental detail will be presented for the High Resolution Doppler Imager (HRDI) which will be used to make the observations of winds from the UARS.
The Tropospheric Emission Spectrometer (TES) for Eos
Authors: Beer Reinhard
Published: February 2023

Increasing concern is being expressed about the impact of anthropogenic emissions on the present and future state of the lower atmosphere: urban & regional pollution; acid deposition; stratospheric ozone depletion; climatological effects of the increase in "greenhouse" gases; etc. There is a clear need for instrumentation to study these questions on a global scale. Accordingly, we describe the concept of a cryogenic infrared (600 - 3450 cm’1; 2.9 - 16.7 μm) imaging Fourier transform spectrometer for observations of the troposphere and lower stratosphere from near-Earth orbit using natural thermal emission and reflected sunlight (when appropriate). The system, called the Tropospheric Emission Spectrometer (TES), has been accepted by NASA for Phase B definition studies leading to flight on one of the Eos polar platforms later this century.
Advantages of Approximate Shot Coincidence with a Space-Based Doppler Lidar
Authors: Emmitt G.D.
Published: February 2023

A space-based Doppler lidar wind sounder (LAWS) is being proposed as an EOS facility instrument. On a polar orbiting platform, LAWS is expected to provide a global set of wind profiles throughout the troposphere. These profiles will be bounded below by the earth’s surface or opaque clouds and limited to those areas having sufficient aerosols and/or thin cirrus.
Remote FTIR Measurement of Volatile Organic Chemicals
Authors: Simpson Orman A. , Kagann Robert H. , Herget William F.
Published: February 2023

Longpath FTIR remote sensors have been used to make precise measurements of volatile organic chemicals in the vicinity of chemical plants and hazardous waste sites.
High Repetition Rate Continuously Pumped Injection Seeded Nd:YAG Laser Extends High Spectral Resolution Lidar Capabilities
Authors: Grund C. J. , Eloranta E. W.
Published: February 2023

The University of Wisconsin High Spectral Resolution Lidar (HSRL) directly measures aerosol1and cloud particle2backscatter cross sections, optical depths, and backscatter phase functions. The HSRL technique spectrally separates the lidar return into molecular and aerosol scattering contributions. This is possible because the backscatter spectrum from molecules is Doppler-broadened by thermal motions. Particles are more massive than molecules, thus exhibit slower Brownian motions which produce insignificant broadening of the backscatter spectrum. Using the known distribution of atmospheric density (from available radiosonde or climatology), the molecular scattering cross section is calculated and provides a calibration target available at every range. Extinction is unambiguously determined from the range dependent decrease in the molecular backscatter intensity. The ratio of particle to molecular backscatter intensities provides the particle backscatter cross section at each range. Whenever gaseous and particle absorption are negligible, the particle backscatter phase function is directly determined.
Ozone DIAL at Observatoire de Haute Provence
Authors: Godin Sophie
Published: February 2023

This project has been unique in its scope, magnitude, longevity, and challenge. The project scientist of eleven years gives a personal history of this observatory which will be launched next March.
Method for Combined Ground-Based Umkehr and SBUV Ozone Profilers for Improved Monitoring of Stratospheric Ozone Trends
Authors: DeLuisi John , Longenecker David , Mateer Carl
Published: February 2023

The Umkehr and SBUV methods for deriving stratospheric ozone profile information are based upon backscatter and forward scatter of ultraviolet radiation. A strong relationship exists between the two types of measurements when the instruments view the same atmosphere. An algorithm was developed to estimate SBUV albedo from Umkehr measurements, therefore, permitting a continuous check on the calibration of the SBUV which is known to drift with time.

We will present the preliminary results of our method to estimate the calibration change of SBUV and the effect that this change produces on stratospheric ozone profile trends. We will also describe the errors associated with the mathematical and experimental aspects of the combined method.
GSFC Lidar Measurements of Ozone: Results of the STOIC Intercomparison
Authors: McGee T. J. , Ferrare R. , Whiteman D. , Burris J. F. , Owens M. , Butler J.
Published: February 2023

During the month of July, 1989, the GSFC mobile lidar was deployed at the Table Mountain Facility of the Jet Propulsion Laboratory. The purpose was to take part in a NASA sponsored "blind" ozone intercomparison, predominantly with a view towards validating the lidar technique as an accurate, precise method for the long-term measurement of ozone. Differential absorption lidar (DIAL) is currently being considered as a major instrument in the proposed Network for the Detection of Stratospheric Change (NDSC).
Use of Large Solar Collector for Rayleigh Lidar
Authors: McNutt Lt Ross , Dao P.D. , Meriwether J.W. , Moskowitz W.
Published: February 2023

A design effort considered a large solar collector as a lidar receiver for the Geophysics Laboratory's High Altitude Mobile Lidar system. There exists a large 11 meter diameter parabolic dish solar collector that is available for lidar applications at Sandia National Laboratory's Solar Test Facility at Kirtland AFB, MN. In particular, we describe the characteristics of the Sandia Test Bed Concentrator #1 and #2. See Figure 1. This facility was designed in the early 1980's at the height of the solar energy research effort for approximately $500,000. It provides 95 square meters of receiving area, 19 times more area than we currently have with the 100 inch collimator facility at Wright Patterson AFB and 120 times more than we have at our GL penthouse facility. The large increase in collection area would appear to provide major improvements in the sensitivity of rayleigh lidar. Unfortunately, the increased difference in optical blur circle diameter has a significant impact on signal return at altitudes where the statistical error is background limited as opposed to signal limited.
CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere - CRISTA
Authors: Grossmann K. U. , Offermann D.
Published: February 2023

The distribution of trace gases in the middle atmosphere results from the interplay of photochemistry and dynamics. More and more refined 3-D models of the atmosphere as well as local soundings by balloons and rockets reveal an atmosphere which is highly structured horizonatally, vertically, and in time. The spatial dimensions of such structures span the wide range from global scale planetary waves to local turbulence. Today's remote sensing satellites generally exhibit a good spatial resolution when vertical scales are considered. In the horizontal plane, however, their resolution is limited to the distance between two adjacent orbits. In order to improve the spatial resolution and to detect and analyse small scale structures the experiment CRISTA is planned.
Raman/Rayleigh lidar measurements during a major stratwarm in Greenland
Authors: Farley R. , Meriwether J.W. , McNutt R. , Dao P. , Moskowitz W. , Davidson G. , Mikkelsen Ib , Larsen M.
Published: February 2023

Rayleigh lidar observations of atmospheric temperatures below 30 km are contaminated by the Mie backscattering from the sulphate stratospheric aerosols that normally exist between 12 and 25 km. Consequently, the fact that nitrogen Raman lidar returns for vibrational and rotational Raman backscattering are red-shifted offers the opportunity to extend the Rayleigh lidar measurements to lower altitudes by joining the two relative density profiles at a height where the Mie backscattering contamination may be ignored. This technique was applied by us previously with the aim of providing an improved means of normalizing lidar measurements of upper atmosphere densities against simultaneous balloon measurements. Because lower stratosphere temperatures below 195 °K will support the production of polar stratospheric clouds (PSC) designated as Type 2 nitric acid trihydrate (NAT) and for temperatures below the frost point, nominally 190 °K, the production of Type 1 water ice PSCs. To study the possible formation and evolution of these polar stratospheric clouds, we undertook to make measurements of temperatures in the winter Arctic with a Raman augmentation of our mobile Rayleigh lidar facility. While the results did not show any indications of the production of PSCs, the profiles did show substantial dynamic activity in connection with the progression of a major stratospheric warming.
A Modified Stratospheric Ozone Lidar
Authors: McGee Thomas J. , Butler James J. , Gross Michael , Singh Upendra , Cavanaugh John F.
Published: February 2023

In June and early July 1991, the GSFC mobile lidar was deployed at JPL's Table Mountain Facility for the purpose of a series of engineering tasks. Since its last deployment at Cannon AFB in Clovis, NM, the lidar has been extensively rebuilt. The resulting system now has greater sensitivity and greater accuracy than before particularly above forty kilometers.
Remote Detection of Atmospherically Dispersed Vegetative Cells Using Fluorescence Lidar
Authors: Tiee J. J. , Hof D. E. , Karl R. R. , Martinez R. J. , Moore D. S. , Quick C. R. , Eichinger W. E. , Holtkamp D. B. , Joseph R. J.
Published: February 2023

A lidar system based on ultraviolet (UV) laser induced fluorescence (LIF) has been developed for the remote detection of atmospherically dispersed biological particles, such as the vegetative cells of bacillus thuringiensis (BT) and bacillus globiggi (BG) released from an aerosol generator. The main goal of this work is to investigate the research issues associated with the long range detection and identification of these biological materials using fluorescence lidar. In particular, we are interested in extending the detection range of a solar-blind 248-nm lidar system demonstrated (with a range of 1-km or so) in previous field experiments1. To ensure favorable atmospheric light transmission characteristics in longer range detection, we are using excitation laser wavelengths > 290-nm (i.e. at wavelengths above that of ozone absorption).
Atmospheric Constituent Density Profiles Full Disk Solar Occultation Experiments
Authors: Lumpe J. D. , Chang C. S. , Strickland D. J.
Published: February 2023

In this paper, we describe mathematical methods which can be used to deduce number density profiles of atmospheric constituents from full disk solar occultation measurements. This algorithm has been developed for use in the analysis of solar occultation data which will be obtained from the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) on the UARS satellite. Inversion of full disk occultation data presents special problems because the apparent size of the source, as seen by the detector, is generally large compared to the local atmospheric scale height. A single measurement therefore consists of light received from widely separated ray paths, which collectively sample a region of the atmosphere over which the density distribution of the absorbing species can vary significantly.
SPEAM-I Observations of High-Altitude Ozone from STS 41-G
Authors: McElroy C.T. , Kerr J.B. , Wardle D.I. , McArthur L.J.B. , Shah G.M. , Garneau M. , MacLean S.G. , Thirsk R. , Davies J.A. , Evans W.F.J. , Nicholls R.W. , McConnell J.C. , Cann M.
Published: February 2023

The Sunphotometer Earth Atmosphere Measurement (SPEAM-I) experiment was flown on the United States Space Shuttle Challenger in October, 1984 as part of a group of Canadian experiments referred to as CANEX-I. Measurements of the solar intensity were made through the orbiter side-hatch window at various wavelengths in the visible and near-ultraviolet during a number of terminator crossings using a hand-held, interference filter photometer. Observations at 315 and 324 nm have been analyzed to give vertical profiles of ozone at 63.34°S, 91.96°E. These profiles are compared to data from the literature. The success of this experiment points the way to the use of small instruments to make accurate but inexpensive observations of the composition of the upper atmosphere.
Advances in Retrieval Methodology for the Analysis of Present and Future Generations Vertical Sounders
Authors: Chedin A. , Scott N.A. , Cheruy F. , Escobar J. , Rieu H.
Published: February 2023

The ARA (Atmospheric Radiation Analysis) group at LMD has developed a good experience in the retrieval of atmospheric temperature and moisture profiles with the "3I" (Improved Initialization Inversion) algorithm using TOVS observations. However, for operational numerical weather prediction or climate researches, the weaknesses of this kind of observations are now well recognized: too limited vertical resolution and accuracy (= 2K rms in temperature and 20-30 % in water vapor profiles). The high spectral resolution infrared sounders like AIRS (Atmospheric Infrared Sounder) or IASI (Improved Atmospheric Sounding in the Infrared) will provide a great improvement in the retrieval of atmospheric and surface properties. Such an increase in spectral resolution in the observations will be successful only if the processing tools are adequate. Among them are : a fast and accurate radiative transfer model, a carefully selected set of channels throughout the infrared spectrum, a well elaborated retrieval/assimilation procedure. This paper presents an overview of these developments, a special emphasis being given to the latter one. Results recently obtained within the frame of the activities of the AIRS scientific team in cooperation with GLA (Goddard Laboratory for Atmosphere) will be discussed.
NDSC Infrared Observations at Mauna Loa, Hawaii
Authors: Murcray F.J. , Murcray D.G. , David S.J. , Blatherwick R.D. , Kosters J.J. , Murcray F.H. , Goldman A. , Rinsland C.P.
Published: February 2023

Since May 1991, the University of Denver is involved in high resolution infrared atmospheric measurements at Mauna Loa, Hawaii, one of the Network for Detection of Stratospheric Change (NDSC) primary sites, using a BOMEM DA3.002 interferometer. Additional measurements for monitoring and intercomparisons are made at Denver, with a BRUKER IFS HR and BOMEM DA3.002 interferometers. More recently, the involvement has been extended to several complementary NDSC sites.
Comparison of Ozone Columns between FTIR and CLAES over Mauna Loa, Hawaii
Authors: David Shelle , Beaton Sheryl , Goldman Aaron , Murcray Frank , Roche Aiden , Kumer Jack
Published: February 2023

Very high resolution infrared solar spectra have been collected from Mauna Loa Observatory by a Fourier Transform Spectrometer (FTS) system. Observations have been made every Wednesday morning (weather permitting) since November, 1991, by the staff of the Observatory, which is operated by the Climate Monitoring and Diagnostics Laboratory of NOAA. The instrument currently covers two spectral regions: 800 to 1200 cm−1 and 2800 to 3200 cm−1. Many atmospheric gases have absorptions in these regions which can be used to recover abundance information. Both regions include absorptions due to ozone. For this study, regions near 1146 and 1163 cm−1 have been fitted to recover ozone columns.
Demonstration of a New GFCR Method with CH4 Measurements at 2.3 microns
Authors: Wang Liang-guo , Sachse Glen , LeBel Peter , Wallio Andrew , Vay Stephanie
Published: February 2023

Over the past 20 years, gas filter correlation radiometers (GFCR's) have made important contributions to our knowledge of the atmosphere by providing remote measurements of a number of gas species from aircraft, balloon, and spacecraft platforms. Though GFCR's have many attractive features , these instruments are generally mechanically complex, often requiring rapidly moving mechanical parts. A new GFCR concept has been reported by Sachse et al. 1 According to this concept a polarization modulator is used in conjunction with a polarization beamsplitter as a solid-state optical switch to rapidly alternate the path of incoming radiation between the two GFCR's optical paths (i.e., the paths containing the gas correlation and vacuum cells). Because this concept does not require rapidly moving parts, it has several potential advantages for remote sensing from space, including high reliability, efficiency and long operational life time.
The Remote Sensing of Tropospheric Gases by Thermal Emission Spectroscopy
Authors: Evans W.F.J. , Puckrin E.
Published: February 2023

A technique for the remote sensing of tropospheric gases for air pollution and global warming has been developed. Models of global warming depend on the measured laboratory absorption spectra of Radiatively Active Gases, yet the atmosphere works on the radiative transfer of thermal emission. An outstanding question is then: are there discrepancies between calculations of radiation codes and atmospheric fluxes? Models of the global warming use laboratory absorption spectra of gases as a basis for radiative transfer calculations. In the atmosphere, the greenhouse effect actually arises through the emission of Planck blackbody radiation from atmospheric gases and aerosols. The measurement of atmospheric gases by thermal emission spectroscopy with FTIR technology is described using a technique which has recently been developed for measuring the thermal emission spectra of gases in a infrared cell in the laboratory. In particular, CFC11, CFC12, HNO3, NO2, SO2, CH4, CH4,C4H10 and N2O5 have been measured in the laboratory. These gases are of importance for investigations of the tropospheric chemistry of air pollution and global warming. The gases measured in the atmosphere include CFC11, CFC12, CFC22, ethylene and nitric acid. As an example, the thermal emission spectrum of CFC11 has been measured in detail. This is compared with the measured laboratory absorption spectrum and with the spectrum of CFC11 from an atmospheric observation. Atmospheric spectra indicating the presence of the several gases have been measured. It is shown that absorption spectra of these gases may not be adequate for detailed radiative transfer calculations in greenhouse models and for satellite thermal emission analysis.
A Ground-Based System For Measuring Atmospheric Emitted Radiance At High Spectral Resolution
Authors: Revercomb H.E. , Smith W.L. , Knuteson R.O. , Best F.A. , Dedecker R.G. , Dirkx T.P. , Herbsleb R.A. , Short J.F. , Howell H.B.
Published: February 2023

Downwelling spectral radiances will be observed routinely for the Atmospheric Radiation Measurement (ARM) program by a new complement of instruments. Accurate and spectrally detailed observations of the thermal emission from radiatively important atmospheric gases, aerosols, and clouds are crucial for realizing the overall objectives of the ARM program to improve the treatment of radiation and clouds in climate models. The importance of broadband infrared radiation to modeling climatic processes stems, of course, from its basic role in the energy balance of the atmosphere. Observations of the spectrum of infrared radiation also contain a great deal of remote sensing information on the instantaneous state of the atmosphere and on fundamental molecular spectroscopy.
Chlorine Nitrate and Nitric Acid Profiles in the Arctic Vortex Derived from Limb Emission Measurements with MIPAS-B
Authors: Oelhaf H. , Clarmann T. v. , Fischer H. , Friedl-Vallon F. , Fritzsche Ch. , Linden A. , Piesch Ch. , Seefeldner M. , Völker W.
Published: February 2023

Investigation of chemical and physical processes driving the composition of the polar stratosphere and being responsible for the formation of the ozone hole over the Antarctic continent each spring is a major topic of stratospheric research. In particular in the Arctic region knowledge of the distribution of primary reservoir and reactive species is rather poor. While several publications appeared on column amount measurements from ground and from aircrafts, no vertical distributions have been reported till now on some key reservoir molecules like ClONO2, HCl and N2O5. Imbedded in the European Arctic Stratospheric Ozone Experiment (EASOE) the balloon-borne version of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) had two flights near the northern polar circle in January and March 1992. This report gives an overview on the large amount of information recorded and focusses on the analysis of vertical profiles of ClONO2 and HNO3.
ECLIPS Phase 2 at LMD
Authors: Valentin R. , Elouragini S. , Flamant P.H. , Menenger L. , Pelon J.
Published: February 2023

The LMD ground-based backscatter lidar station (48°4 N, 02°0E) near Paris was operated daily (Monday through Friday) during ECLIPS phase 2 from May 22 to June 19, 1991, with a simultaneous recording of the downward short wavelength (SW) flux and long wavelength (LW) flux. A day-by-day summary of the field measurements is displayed as a function of universal time (UT) on figure 1. There are only two days of missing data (05/31 and 06/06) in our record due to bad weather conditions. The nearby meteorological station (10 km away) provides with rawindsondings twice a day (00UT and 12UT). We have also collected the meteorological observations and synoptic weather charts. In addition, in two occasions (05/22 and 05/27) LEANDRE the french airborne backscatter lidar was flown over the ground-based station to make simultaneous lidar measurements looking from above and below.
The Results of Laser Measurements of Cloud Parameters under the ECLIPS Program
Authors: Khmelevtsov S.S.
Published: February 2023

Cloud condition measurements were carried out in the period from 29 May 1991 to 29 June 1991 at Obninsk lidar station. The lidar, operating daily at the wavelength of 532 nm over 24 days from 2.5 to 4.5 h., when NOAA satellites overpassed Obninsk, where the measurements of outgoing infrared irradiance flows were carried out. The overall duration of the measurements is 55 h. According to laser sounding results computations were carried out at the height of the cloud bases, the top of clouds, and the optical thickness of clouds (in those cases when it was possible to do).
Tunable Mid Infrared Source for Remote Sensing
Authors: Barnes Norman P. , Murray Keith E. , Jani Mahendra G.
Published: February 2023

A tunable mid infrared source could serve a multifunction role for remote sensing of atmospheric constituents such as greenhouse gasses and ozone. While atmospheric constituents which are more plentiful or have a strong dipole moment can utilize weak overtone features in the near infrared, atmospheric constituents which are less plentiful or have smaller dipole moments must reply on the fundamental absorption features in the mid infrared. For lighter gasses, such as the greenhouse gasses, these features are found in the 2.5 to 5.5 μm region. Consequently, NASA Langley is developing the laser technology to provide a tunable mid infrared source suitable for DIAL applications.
An Assessment of the Effects of Diffraction on Infrared Measurements from Geosynchronous Orbit
Authors: Montgomery Harry E. , Shenk William E.
Published: February 2023

The effects of diffraction were calculated for selected current and future geosynchronous satellite infrared profiling and imaging channels. The future geosynchronous satellite calculations were made for the GOES I-M instruments. For comparison, some calculations were also made for similar measurements in low earth orbit. The results indicate that substantial diffraction effects, as high as 17 K, are and will be present for geosynchronous 15 μm profiling channels and 11 μm profiling and imaging channels when clouds are close to the sensor instantaneous field-of-view and the difference between the equivalent blackbody temperature between the cloud and the dear air scene is ≥ 20 K Similar diffraction calculations at 4 μm show a reduction of 5-10 K in the diffraction effects which suggests that, wherever possible, 4 μm channels should be used for profiling and imaging whenever quantitative radiometric measurements are made of surface properties (e.g. surface temperature).
Lidar Developments for Tropospheric Ozone Research in Europe
Authors: Bösenberg Jens
Published: February 2023

The TESLAS subproject of the joint European environmental programme EUROTRAC has started an initiative to develop accurate, reliable, and easy to operate lidar systems for measurements of the ozone vertical distribution in the troposhere. The progress is reported.
Characteristics of the Improved Limb Atmospheric Spectrometer and validation experiment plan
Authors: Sasano Yasuhiro , Kanzawa Hiroshi , Suzuki Makoto , Yokota Tatsuya
Published: February 2023

The Advanced Earth Observing Satellite (ADEOS) which is planned for launch in early 1996 by National Space Development Agency of Japan (NASDA) will carry an atmospheric sensor "Improved Limb Atmospheric Spectrometer (ILAS)" developed by Japan Environment Agency (EA) (Sasano et al., 1992). The ILAS measures the atmospheric absorption spectrum in the visible channel (from 753 nm to 784 nm in wavelength) and in the infrared channel (from 850 cm-1 to 1610 cm-1 in wavenumber) to get vertical profiles of O3 and ozone chemistry related species and parameters such as HNO3, NO2, N2O, H2O, CH4, CFC11, aerosols and temperature based on the solar occultation method. The measurements are made for the stratosphere (from about 10 km to 60 km) over the high latitude regions in both hemispheres (55 - 70 degrees North and 63 - 87 degrees South). The longitudinal resolution is about 25 degrees.
Development of the Prototype CO Profile Retrieval Algorithm for the MOPITT Instrument
Authors: Pan Liwen , Gille John , Bailey Paul
Published: February 2023

The Measurements of Pollution in the Troposphere (MOPITT) instrument is designed to measure CO and CH4 in the troposphere from a satellite platform. This instrument has been selected to be on the Earth Observing System (EOS)’s AM platform, which is scheduled to be launched in 1998. One of the objectives of the experiment is to measure the vertical distribution of carbon monoxide (CO) in the troposphere to 10% accuracy. This paper presents the development work for the prototype profile retrieval algorithm currently in progress.
Remote Sounding of Surface Radiative Fluxes in Cirrus Cloudy Conditions
Authors: Ou S. C. , Liou K. N.
Published: February 2023

It has been long recognized that radiation and radiation perturbations play a critical role in the climate system (Liou 1992). Surface radiative fluxes are useful parameters for monitoring global change, for understanding of the effects of clouds on the radiation field, and for improving parameterization of surface sensible and latent heat fluxes. Monitoring of the radiation budget at the top of the atmosphere has been one of the prime satellite programs for the last 30 years. However, monitoring radiative fluxes at the surface over the globe from space cannot be performed in a direct way at the present time. In particular, since clouds are the prime regulators of the radiative fluxes, uncertainties in the retrieved cloud parameters, which are inputs to radiative transfer models, can introduce significant errors in the computed radiative fluxes. Thus, remote sounding of surface radiative fluxes in cloudy conditions requires the development of both satellite cloud retrieval scheme and radiation models.
Temperature and Water Vapor Information Content Densities of the National Polar Orbiting Environmental Satellite System
Authors: Huang H.-L. , Whipple M. S. , Smith W. L. , Purser R. J.
Published: February 2023

By using the techniques developed by Huang and Purser, 1996, the information content density can be uniformly analyzed for both infrared and microwave remote sensing systems for various atmospheric retrieval profiles (e.g., temperature, water vapor, trace gases). In this paper, the information content of the forthcoming polar orbiting sounding systems, such as the Advanced TIROS Operational Vertical Sounder (ATOVS) and candidate instruments for the National Polar Orbiting Environmental Satellite System (NPOESS), are presented. Temperature and water vapor information content profile densities are expressed in terms of Shannon’s Entropy Reduction (ER), a measure of the information gain in the atmospheric profile due to the satellite measurements, and the Degrees of Freedom for Signal (DFS), a value which quantifies the number of independent pieces of information inherent in the both the satellite measurements and the background.
Remote Sensing of Aerosols with Multi-Angle Imaging
Authors: Kahn R.
Published: February 2023

We explore the ability of Multi-angle, multi-spectral remote sensing observations anticipated from the EOS MISR instrument, to retrieve aerosol optical depth, size, shape, and composition, globally.
“Missing Chemistry” and Stratospheric H2O2
Authors: Jucks K.W. , Johnson D.G. , Chance K.V. , Traub W.A. , Toon G.C. , Sen B. , Salawitch R.J.
Published: February 2023

We measure H2O2 in the stratosphere, along with OH, HO2, O3, and temperature.
Nonlinear Optical Activity in Second-Harmonic Generation from a Chiral Surface
Authors: Persoons André , Verbiest Thierry , Kauranen Martti
Published: February 2023

We have observed that the efficiency of second-harmonic generation from a monolayer of chiral molecules depends on the handedness of the incoming fundamental beam. This circular-difference effect is observed both in reflection and transmission of the second-harmonic radiation. Analogous to linear optical activity, we show that these effects can be explained by including contributions of magnetic-dipole transitions to the second-order nonlinear susceptibility.
Recent Progress in Polymer Electroluminescence: Electron Transport Polymers and Microcavity Devices
Authors: O’Brien D. , Weaver M.S. , Pavier M. , Bleyer A. , Lidzey D.G. , Martin S.J. , Tajbakhsh A. , Pate M.A. , Meng Sun , Fisher T.A. , Richardson T. , Searle T.M. , Skolnick M.S. , Bradley D.D.C.
Published: February 2023

We present results concerning the design, synthesis and characterisation of new electron transport polymers and the fabrication and operation of polymer microcavity LEDs.
Electro-optic measurement of the electric-field distributions in coplanar-electrode poled polymers
Authors: Wu J.W.
Published: February 2023

In electro-optic thin film samples, two configurations of electrodes are commonly adopted for the electric field poling, parallel and coplanar. In the parallel-plate configuration, electro-optic (EO) polymer is sandwiched between two thin electrode plates on top of a substrate. Because the size of electrodes is larger than the polymer thin film thickness, the electric field distribution is almost uniform inside the polymer film between the top and bottom electrodes. In the coplanar electrode structure, two thin separate electrodes with a narrow gap in between them are deposited on top of substrate, and EO polymer film is spin coated. Here the film covers both electrodes and the dc poling and EO effect measuring fields pass through and above the film making the electric field distribution complicated. Furthermore the electric field lines have different shapes for different thickness of thin films, since the dielectric constant of polymer films is different from that of the air.
Electric Field Effects in Poled Polymer Thin Films
Authors: Ostrowski Mark H. , Lackritz Hilary S.
Published: February 2023

Polymer thin film systems have been explored as potential materials for nonlinear optical (NLO) device applications using second order nonlinear optical effects such as second harmonic generation and linear electrooptic effect for photonic devices including waveguides and frequency doublers. For second order nonlinear effects to be observed, a noncentrosymmetric orientation of the NLO chromophores, which is obtain by poling with a large magnitude electric field, is necessary. The effects of the electric field during and following poling are poorly understood. During poling, charge is injected into the polymer film affecting the local electric field that the NLO chromophores senses. After poling, these charges that have become trapped in the polymer film system affect the decay of the NLO properties of the film. Therefore, to make efficient nonlinear optical devices, it is necessary to understand the electric field effects on the thermal and temporal stability of chromophore orientation within the polymer thin film system as a function of processing. Electroreflection and dielectric relaxation measurements were performed on poly(methyl methacrylate) doped with 4-dimethylamino-4'-nitrostilbene (DANS).
Electro-optic Polymer Waveguide Devices - Materials, Fabrication, and Applications
Authors: Steier William H.
Published: February 2023

This presentation will include a discussion of three of the promising areas where electro-optic polymers have unique advantages (i) high bandwidth traveling wave external optical modulators operating at millimeter wave frequencies (>30 GHz), (ii) monolithic integration of EO polymers with VLSI electronics for high speed opto-electronics, and (iii) photonic sensing and measuring, without metal electrodes, of electro-magnetic fields.
Design Philosophy For Moderate Plus And Minus Power Aspherical Lenses
Authors: Guilino Günther H. , Wehmeyer K.
Published: February 2023

Classification

1. Application Aspects:

1.1 Aspherical lenses designed mainly to improve the peripheral imaging quality. Such aspherical surfaces are used when the effects of bending no longer lead to success in the high plus range over (+8 D).

1.2 Aspherical lenses designed mainly for cosmetic purposes. Such aspherical surfaces are used in the high minus power range below (-8 D). From the corrective center area towards the periphery there is a continuous transition of the surface in order to flatten out the steep concave curvature. In this process the edge thickness is reduced dramatically. The lenticular design here does not, however, have any steps or edges and so offers a better cosmetic appearance than conventional lenticulars.

1.3 Aspherical lenses with a continuous power increase. Such lenses are termed Progressive Addition Lenses (PALs). They are designed for a comfortable correction of presbyopia and have the advantage of showing no optical discontinuities over the whole visual field.

1.4 Aspherical lenses with increased comfort in wear. In the moderate power range, ametropes can indeed be provided with a truly satisfactory correction using the standard solution of spherical surfaces. If, however, aspherical surfaces are used, then the wearing properties can be improved to a large extent. By wearing comfort we mean the result of harmonizing such different characteristics as the imaging properties, the weight and the cosmetic appearance. The optimization processes provides for the reduction of center or rim thickness, for a lower bending (so that the lens apex will no longer protrude so far out of the frame plane with larger eyeshapes) and at the same time the optical quality of the spherical standard should be maintained or even improved.
Ocular Aberrations and Their Clinical Implications
Authors: Charman W.N.
Published: February 2023

The study of ocular aberration can be traced back at least as far as Newton, but detailed measurements of the aberrations of the individual eye and of the quality of the retinal image have only become possible within the last few decades and then only on a research, rather than a routine clinical, basis. Although measurements on limited numbers of what are usually young adult subjects under laboratory conditions give valuable insights into the general nature of the optical characteristics of the eye, and hence the limitations that they set on overall visual performance, such measurements are not necessarily helpful in identifying the likely, aberration-related, optical problems of the individual patient. For example, if ocular aberrations vary widely, it may not be surprising that different individuals with the same sphero-cylindrical prescription show varying levels of tolerance to the same design of corrective lens, since the overall lens-eye aberrations and resultant retinal image quality may differ substantially.
Modulation Transfer Function of Eyes Implanted with Intraocular Lenses
Authors: Navarro Rafael , Ferro Manuel , Artal Pablo , Miranda Ismael , Crespo Marceliano
Published: February 2023

To implant intraocular lenses (IOL) is a common technique in cataract surgery. At the beginning, only monofocal lenses were used, but lately also different types of multifocal IOLs are available1. In the evaluation of postoperatory visual performance, contrast tests, such as CSF, are replacing visual acuity, since contrast is recognized as a key parameter in both optical quality (Modulation Transfer Function, MTF) and visual performance (Contrast Sensitivity Function, CSF). Although the CSF contains information about the optical quality of the eye, it strongly depends also on retinal, neural and even psychological factors. MTF estimates of IOLs are usually available by both designer computations and optical bench measurements. However the real MTF of the implanted eye could largely differ from these previous estimates, because of many factors such as subject variability, lens decentering, shifts, tilts, etc. In consequence a direct measurement of the MTF is necessary, if one really wants to know the resulting optical performance of the implanted eye.
Transmittance of Infant Lens and New UV- and Blue Light Absorbing Contact Lenses for Aphakic Children
Authors: Ostrovsky Michail A. , Fedorovich Irina B. , Ilyakova Larisa A. , Zack Pavel P. , Mardaleishvili Irina R. , Anisimov Vasily M.
Published: February 2023

We have studied the phenomenon of age-related yellowing of human lens carefully for large number of postmortem donor lenses from newborn up to 82 ages . The lens transmittance has been registrated using Shimadzu MPS-5000 Spectrophotometer.