Updated and expanded, the third edition of Photonics Rules of Thumb represents an evolving, idiosyncratic, and eclectic toolbox intended to allow any engineer, scientist, manager, marketeer, or technician (regardless of specialty) to make rapid and accurate guesses at solutions in a wide range of topics during system design, modeling, or fabrication. This book will help any electro-optics team to make quick assessments, generally requiring no more than a calculator, so that they can quickly find the right solution for a design problem.
This book has been assembled to introduce anyone working in the optics and photonics community to a wide range of critical topics through simple calculations, graphics, equations, and explanations. Useful design principles and rules, simple-to-implement calculations, and numerous graphs and tables of important basic information allow you to rapidly pinpoint trouble spots, ask the right questions at meetings, and are perfect for quick checks of last-minute specifications or performance feature additions. Offering a convenient arrangement according to specialty, this unique reference spans the spectrum of photonics. Eighteen chapters cover optics, atmospherics, radiometry, focal plane arrays, degraded visual environments, economics, and photogrammetry, as well as technologies related to security and surveillance systems, infrared, lasers, electro-optics, phenomenologies, self-driving vehicles, and many others.
A Missile Defense Sensor is a complex optical system, which sits idle for long periods of time, must work with little or no on-board calibration, be used to find and discriminate targets, and guide the kinetic warhead to the target within minutes of launch. A short overview of the Missile Defense problem will be discussed here, as well as, the top-level performance drivers, like Noise Equivalent Irradiance (NEI), Acquisition Range, and Dynamic Range. These top-level parameters influence the choice of optical system, mechanical system, focal plane array (FPA), Read Out Integrated Circuit (ROIC), and cryogenic system. This paper will not only discuss the physics behind the performance of the sensor, but it will also discuss the "art" of optimizing the performance of the sensor given the top level performance parameters. Balancing the sensor sub-systems is key to the sensor’s performance in these highly stressful missions. Top-level performance requirements impact the choice of lower level hardware and requirements. The flow down of requirements to the lower level hardware will be discussed. This flow down directly impacts the FPA, where careful selection of the detector is required. The flow down also influences the ROIC and cooling requirements. The key physics behind the detector and cryogenic system interactions will be discussed, along with the balancing of subsystem performance. Finally, the overall system balance and optimization will be discussed in the context of missile defense sensors and expected performance of the overall kinetic warhead.
The optical system of the James Webb Space Telescope (JWST) is split between two of the Observatory's element, the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM). The OTE optical design consists of an 18-hexagonal segmented primary mirror (25m2 clear aperture), a secondary mirror, a tertiary mirror, and a flat fine steering mirror used for fine guidance control. All optical components are made of beryllium. The primary and secondary mirror elements have hexapod actuation that provides six degrees of freedom rigid body adjustment. The optical components are mounted to a very stable truss structure made of composite materials. The OTE structure also supports the ISIM. The ISIM contains the Science Instruments (SIs) and Fine Guidance Sensor (FGS) needed for acquiring mission science data and for Observatory pointing and control and provides mechanical support for the SIs and FGS. The optical performance of the telescope is a key performance metric for the success of JWST. To ensure proper performance, the JWST optical verification program is a comprehensive, incremental, end-to-end verification program which includes multiple, independent, cross checks of key optical performance metrics to reduce risk of an on-orbit telescope performance issues. This paper discusses the verification testing and analysis necessary to verify the Observatory's image quality and sensitivity requirements. This verification starts with component level verification and ends with the Observatory level verification at Johnson Space Flight Center. The optical verification of JWST is a comprehensive, incremental, end-to-end optical verification program which includes both test and analysis.
The Ozone and Mapping Profiler Suite (OMPS) is an instrument suite in the National Polar-orbiting Operation Environmental Satellite System (NPOESS). The OMPS instrument is designed to globally retrieve both total column ozone and ozone profiles. To do this, OMPS consists of three sensors, two Nadir Instruments and one Limb Instrument. Each OMPS sensor has an End-to-End Model (ETEM) developed using the Toolkit for Remote Sensing, Analysis, Design, Evaluation, and Simulation (TRADES), a Ball Aerospace proprietary set of software tools developed in Matlab. The end-to-end modeling activities, which includes a radiative transfer model, the ETEM, and retrieval algorithms, have three fundamental objectives: sensor performance validation, aid in algorithm development, and algorithm robustness validation. The end-to-end modeling activities are key to showing sensor performance meets the system level Environmental Data Record (EDR) requirements. To do this, the ETEM incorporates sensor data; including point spread functions, stray light, dispersion, bandpass, and focal plane array (FPA) noise parameters. The sensor model characteristics are first implemented with predictions and updated as component test data becomes available. To evaluate the system’s EDR performance, the input radiance derived from the radiative transfer model is entered into the ETEM, which outputs a simulated image. The retrieval algorithms process the simulated image to determine the ozone amount. The system level EDR performance is determined by comparing the retrieved ozone amount with the truth, which was entered into the forward model. Additionally, the ETEM aids the algorithm development by simulating the expected sensor and calibration data with the expected noise characteristics. Finally, the algorithm robustness can be validated against extreme conditions using the ETEM.
Ball Aerospace & Technologies Corp. has an extensive history in modeling and simulation. Ball Aerospace has developed integrated system models for the Very Large Telescope (VLT) for European Southern Observatory (ESO), for the James Webb Space Telescope (JWST), for several NPOESS instruments including the Visible/Infrared/Radiometer Suite (VIIRS), the Conical Scanning Microwave Imager/Sounder (CMIS), and the Ozone Mapping Profiling Suite (OMPS), and many others. As a result, Ball Aerospace has developed a proprietary modeling and simulation tool, TRADES, that is used to analyze space-based systems. TRADES (Toolkit for Remote-Sensing Analysis, Design, Evaluation and Simulation) is a set of software tools in Matlab, designed and developed for simulating, analyzing, evaluating, and conducting design trade studies of remote sensing imagers. It supports simulations and analysis in any spectral regime, most scene sampling designs, and many sensor types. TRADES will provide a physically accurate simulation of a space-based system. This allows for trade studies to analyze the performance of different configurations, definition of subsystem specifications and error budgets for system performance, sensitivity analysis, and the optimization of instrument design to viewing. Explanations of TRADES’ major components will be presented along with examples of its use on several programs.
The Ozone Mapping and Profiler Suite (OMPS) for the United States National Polar-orbiting Operational Environmental Satellite System (NPOESS) consists of a two sensor suite and Level 1 and 2 data
processing algorithms to produce calibrated radiance data and ozone total column and profile values. We describe the profiling system design that matches the limb-observing space sensor performance to
measurement requirements of the retrieval algorithm and uses algorithm techniques to achieve the data quality needed for limb-scatter-based ozone profiling.
Space-based, high resolution, Earth remote sensing systems, that employ large, flexible, lightweight primary mirrors, will require active wavefront correction, in the form of active and adaptive optics, to correct for thermally and vibrationally induced deformations in the optics. These remote sensing systems typically have a large field-of-view. Unlike the adaptive optics on ground-based astronomical telescopes, which have a negligible field-of-view, the adaptive optics on these space-based remote sensing systems will be required to correct the wavefront over the entire field-of-view, which can be several degrees. The error functions for astronomical adaptive optics have been developed for the narrow field-of-view correction of atmospheric turbulence and do not address the needs of wide field space-based systems. To address these needs, a new wide field adaptive optics theory and a new error function are developed. Modeling and experimental results demonstrate the validity of the wide field adaptive optics theory and new error function. This new error function, which is a new extension of conventional adaptive optics, lead to the development of three new types of imaging systems: wide field-of-view, selectable field-of-view, and steerable field-of-view. These new systems can have nearly diffraction-limited performance across the entire field-of-view or a narrow movable region of high-resolution imaging. The factors limiting system performance will be shown. The range of applicability of the wide field adaptive optics theory is shown. The range of applicability is used to avoid limitations in system performance and to estimate the optical systems parameters, which will meet the system’s performance requirements.
A NASA research contract (NAS1-00116) was awarded to Ball Aerospace & Technologies Corp. in January 2000 to study wide field-of-view adaptive optical systems. These systems will be required on future high resolution Earth remote sensing systems that employ large, flexible, lightweight, deployed primary mirrors. The deformations from these primary mirrors will introduce aberrations into the optical system, which must be removed by corrective optics. For economic reasons, these remote sensing systems must have a large field-of-view (a few degrees). Unlike ground-based adaptive optical systems, which have a negligible field-of-view, the adaptive optics on these space-based remote sensing systems will be required to correct for the deformations in the primary mirror over the entire field-of-view. A new error function, which is an enhancement to conventional adaptive optics, for wide field-of-view optical systems will be introduced. This paper will present the goals of the NASA research project and its progress. The initial phase of this research project is a demonstration of the wide field-of-view adaptive optics theory. A breadboard has been designed and built for this purpose. The design and assembly of the breadboard will be presented, along with the final results for this phase of the research project. Finally, this paper will show the applicability of wide field-of-view adaptive optics to space-based astronomical systems.
The Ozone Mapping and Profiler Suite (OMPS) is being developed for the United States National Polar-orbiting Operational Environmental Satellite System (NPOESS). We describe the optical design and predict the performance of the OMPS earth limb-imaging spectrometer. Limb-scattered solar radiation is measured at selected ultraviolet (UV), visible, and near infrared (NIR) wavelengths to determine ozone profile concentrations for the altitude range of 8 to 60 km. The sensor consists of a telescope with three separate crosstrack fields of view of the limb, a prism spectrometer covering 290 to 1050 nm, and a solar-diffuser calibration mechanism. The sensor provides 3 km vertical resolution profiles of atmospheric radiance with channel spectral resolutions (full-width at half-maximum, FWHM) ranging from 2.7 nm in the UV to 35 nm in the NIR and handles the demanding spectral and spatial dynamic range of the limb-scattered solar radiation with the required sensitivity for ozone retrievals.
We describe the features of the optical system for Terrestrial Planet Finder, a space-based, cryogenic interferometer for direct detection of Earth-type planets around nearby stars. Destructive interference in a stellar interferometer suppresses stellar glare by a factor of several thousand or more, and phase chopping distinguishes planet light from symmetric backgrounds. The mid-IR is favorable for detecting planetary emission relative to that from the star, and this spectral region also offers important molecular signatures indicative of key atmospheric gases.
A nulling interferometer for direct detection and spectral studies of the light from extra-solar planets would face daunting technical challenges. We outline a candidate optical architecture, discussing the major challenges in handling the starlight and controlling the optics to produce a deep on-axis null with high transmission a fraction of an arcsecond away.