Mission success is highly dependent on the ability to accomplish Surveillance, Situation Awareness, Target Detection
and Classification, but is challenging under adverse weather conditions. This paper introduces an engineering prototype
to address the image collection challenges using a Common Optical Path, Multiple Sensors and an Intelligent Image
Fusion System, and provides illustrations and sample fusion images. Panavision's advanced wide spectrum optical
design has permitted a suite of imagers to perform observations through a common optical path with a common field of
view, thereby aligning images and facilitating optimized downstream image processing. The adaptable design also
supports continuous zoom or Galilean lenses for multiple field of views. The Multiple Sensors include: (1) High-definition
imaging sensors that are small, have low power consumption and a wide dynamic range; (2) EMCCD sensors
that transition from daylight to starlight, even under poor weather conditions, with sensitivity down to 0.00025 Lux; and
(3) SWIR sensors that, with the advancement in InGaAs, are able to generate ultra-high sensitivity images from 1-1.7μm
reflective light and can achieve imaging through haze and some types of camouflage. The intelligent fusion of multiple
sensors provides high-resolution color information with previously impossible sensitivity and contrast. With the
integration of Field-Programmable Gate Arrays (FPGAs) and Application-Specific Integrated Circuits (ASICs), real-time
Image Processing and Fusion Algorithms can facilitate mission success in a small, low power package.
Optical designers are becoming increasingly aware of the importance of specifying and tolerancing slope errors on
optical surfaces, especially aspheric surfaces. Slope errors can degrade system optical performance - in some cases even
if the peak to valley surface figure errors meets the optical design tolerance analysis. With this awareness, more optical
engineers are putting requirements for peak surface slope on optical element drawings. This puts pressure on optical
fabricators to understand slope specifications and react to these requirements, and use the appropriate metrology
instrumentation to ensure final system performance.
This paper will discuss appropriate ways to specify slope errors, and the challenges and limitations of measuring slope
errors with commercial interferometers. The optical designer should be aware of how slope errors are measured on
Fizeau interferometers and should specify the spatial intervals of interest when tolerancing aspheric elements. Peak
slope error measurement is prone to erroneous measurement errors due to surface contamination, environmental errors,
and pupil focus. Finally, filtering has a strong influence on surface slope calculations. Practical examples of slope
specifications and experimental results will be presented.
Splitting an optical system into two parts separated by an intermediate image is a very fruitful method for designing ultra-wide-angle, ultra-large-aperture lenses. This technique is illustrated by several designs having an extremely large optical invariant. These designs are further characterized by low geometrical distortion and remarkably uniform relative illumination.
In many complex technological fields the primary source of useful information lies not in books or periodicals but rather in the patent literature. Nowhere is this truer than in the field of zoom lens design, where in-depth discussion in books is very scarce but patents number several thousand. Several different types of zoom lenses that are commercially important today have roots in designs that are decades old, and the detailed path of development is publicly documented in the patent literature. These zoom types include the positive-negative type, which has been used extensively in compact 35mm and APS point-and-shoot cameras; the negative positive type, which was originally developed for 35mm SLR cameras and has been widely adopted for use in digital still cameras; and the positive-negative-positive type, which has been used in many applications ranging from 35mm still photography to cinematography to ultra-wide range TV camera objectives. Many innovations have fueled the development of these designs, including the use of aspheric surfaces, plastic lens elements, the use of abnormal partial dispersion glasses to achieve apochromatic correction, and the use of a variety of focusing techniques. Given that the patent literature is the best source of information on zoom lenses, there are a number of reasons that a designer or perhaps a product engineer would want to study this information. First and foremost is to gain a very broad historical understanding and appreciation for the technology. Next is to discover what has been done before by others in order to avoid re-inventing it, and also to increase the likelihood that a new design will be a genuine improvement over past efforts. This alone can save countless hours of work and potentially millions of dollars in development costs. Just as important as finding out has been done is finding out what hasn't been done. This can alert a designer to potentially over-ambitious specifications on a project. It can also aid in the process of creating new and valuable intellectual property. Another highly useful benefit of patent study is that it provides an almost limitless supply of starting points for new design projects. This is especially important in zoom lens design, where the final performance is more heavily dependent on the starting point than simpler fixed focal length lenses. Starting points can also be constructed from numerous different patent designs. For example the negative variator in a PNP type design can be inserted from dozens of different sources into the same basic starting point in order to find the optimum variator form.
The following timeline summarizes the recent advancements made in the development of gel derived radial GRIN lenses in terms of two characteristic optical properties - the size of index of refraction gradient (An) and the diameter of the GRIN element.
Radial gradient index (GRIN) glass rods can be readily made by sol-gel methods. For the preparation of Ti02-Si02 GRIN glass, a sol-gel technique has been used in which a Ti02- Al203-Si02 gel is leached in acid to obtain a radial composition gradient of titania within the gel.?
Spherical aberration in a flat surfaced radial gradient-index lens (a Wood lens) with a parabolic index profile can be corrected by altering the profile to Include higher order terms. However this results in a large amowfl of third order coma. This paper presents an alternative method of aberration correction similar to that used in the catadiopthc Schmidtsystem. A Wood lens with a parabolic profile is used to provide all or most of the optical power. Coma is corrected by stop shifting and Spherical aberration is corrected by placing a powerless Wood lens corrector plate at the stop. 1.
Gradient index optics will play an increasingly important role in applications such as fax machines,
photocopiers, fiber optic couplers and cameras. In this paper, we present an overview of various
sol-gel methods for making gradient index materials.