A concurrent engineering approach to the design and analysis of a space-borne Electro-Optical (EO) sensor is presented.
A detailed design of an infrared telescope payload is developed by an interdisciplinary team of mechanical, structural,
thermal, and optical engineers using a Simulation Driven Engineering (SDE) software environment. The telescope
payload design is also integrated with a conceptual level design of the space segment of a mission that incorporates the
payload. The flow of the concurrent design process is described, and design outputs are provided.
Root causes of mission critical failures and major cost and schedule overruns in complex systems and programs are
studied through the post-mortem analyses compiled for several examples, including the Hubble Space Telescope, the
Challenger and Columbia Shuttle accidents, and the Three Mile Island nuclear power plant accident. The roles of
organizational complexity, cognitive biases in decision making, the display of quantitative data, and cost and schedule
pressure are all considered. Recommendations for mitigating the risk of similar failures in future programs are also
Complex products are best developed in a collaborative design environment where engineering data and CAD/CAE
results can be shared across engineering discipline boundaries within a common software interface. A new software tool
that allows Electro-Optical (EO) sensors to be developed in this manner has been used to conduct an integrated
Structural/Thermal/Optical (STOP) analysis of a critical lens subassembly in a flight payload. This paper provides a
description of the software environment and a summary of the technical results that were produced with it.
We present a design and tolerancing approach that permits the achievement of a high degree of spatial and spectral uniformity of response from a pushbroom imaging spectrometer. Such uniformity of response is crucial for the extraction of accurate spectroscopic information from remotely sensed data. The spectrometer system example comprises two independent spectrometer modules covering the 400 - 2500 nm range, separated through a dichroic mirror. The relative merits of alternative approaches are briefly reviewed before concentrating on the problem of building a flight-worthy system that can approximate its design performance. The tolerancing approach requires simultaneous monitoring of many parameters, and specifically: overall image quality, spectral distortion, spectral MTF variation with field, spatial distortion, spatial MTF variation with wavelength, and slit magnification to within a small fraction of a pixel. It is shown that the wavefront error alone or even supplemented by distortion figures is insufficient for characterizing a system with high response uniformity. Tolerance values on the components and their positioning are primarily guided by the need to achieve the same magnification between the two spectrometer modules, as well as by the interferometric alignment method.
We describe a pushbroom imaging spectrometer having a number of attractive features for remote sensing applications, including compact and simple form, good image quality, high efficiency, and very low levels of distortion. These properties are made possible by the unique characteristics of convex gratings manufactured by electron-beam lithography. A laboratory prototype has been built and is under evaluation. If has an f-number of 2.8, covers a spectral band from 400 to 1000 nm with 3 nm spectral resolution and has 750 spatial elements across the entrance slit. Experimental results are shown that demonstrate very low distortion, on the level of 2 percent of a pixel.
Conference Committee Involvement (10)
Optical Modeling and Performance Predictions XI
23 August 2020 | San Diego, California, United States
Optical Modeling and System Alignment
12 August 2019 | San Diego, California, United States
Optical Modeling and Performance Predictions X
22 August 2018 | San Diego, California, United States
Optical Modeling and Performance Predictions IX
8 August 2017 | San Diego, California, United States
Optical Modeling and Performance Predictions VIII
1 September 2016 | San Diego, California, United States
Optical Modeling and Performance Predictions VII
11 August 2015 | San Diego, California, United States
An Optical Believe It or Not: Key Lessons Learned IV
10 August 2015 | San Diego, California, United States
An Optical Believe It or Not: Key Lessons Learned III
18 August 2014 | San Diego, California, United States
Optical Modeling and Performance Predictions VI
29 August 2013 | San Diego, California, United States
An Optical Believe It or Not: Key Lessons Learned II
2 August 2010 | San Diego, California, United States