Camera Projection Research Articles

Visibility of sunspots

The premier record of long-term solar activity is the sunspot count. After developing a theoretical model of sunspot visibility, this model is tested against observations, and recommendations are made for improved calculation of sunspot counts. The theoretical model's result is a predicted threshold size for sunspot visibility with the unaided (but filtered) eye, direct vision through a telescope, pinhole camera, and telescope projection. Also reported are over 3250 days of sunspot observations from six observers, 38 yr of daily observations by an experienced observer, 1837 days of observations from a network with over 50 experienced observers, observations from 30 inexperienced observers, as well as summaries of results from 102 AAVSO solar observers. The comparison of the observed thresholds with the predicted thresholds reveals agreement to within the uncertainties, so that the model is validated by observation.

THE UH NICMOS-3 NEAR-INFRARED CAMERA

ABSTRACT The UH Near Infrared Camera is equipped with a NICMOS-3 HgCdTe detector array sensitive from -1 to 2.5 microns and produced by the Rockwell International Science Center for the Near Infrared Camera and Multi Object Spectrometer Project (NICMOS). In our camera, the NICMOS-3 array operates with 53 electrons read-noise in double correlated sampling mode. A dark current below 1 electron per second at an operating temperature of 60 K has been achieved. The device works linearly within 1% up to 250000 electrons (2/3 full-well) at 1.0 V bias. Techniques for further reduction in read-noise and dark current are discussed. The only significant remaining problem is a residual excess dark current, remaining from previous exposure of the device.

Reflective mask technologies and imaging results in soft x-ray projection lithography

In this work we investigate and compare a variety of technologies for patterning high resolution Mo/Si multilayer reflective x-ray masks for use at wavelengths near 13 nm. The patterning methods investigated include: absorbing layers deposited on top of multilayer reflectors, reflective coating removal by reactive ion etching and ion damage of multilayer regions to form a planar mask structure. Large area samples were prepared by each of the above methods and reflectivity measurements made to determine the expected mask contrast. The reflectivity data are compared with simulation for the absorber overlayer and etched multilayer measurements. Our results indicate that reflectivity changes between 5 and 300 were effected. Fine patterning tests show that mask features as fine as 0.1 μm can be achieved in each technology. The advantages, process complexity, and limits of each method are discussed. We also report the first use of an x-ray reflectance mask to print 0.1 μm features in resist. The developed resist images obtained using reflection masks in a 20:1 Schwarzschild projection camera compare favorably with transmission mask results obtained using the same optical system.

Measurement of eye rotations in three dimensions and the retinal stimulus projection using scanning laser ophthalmoscopy

A transformation algorithm is introduced to specify eye rotations in three dimensions from two-dimensional translations of ocular fundus landmarks dynamically monitored by means of the novel Scanning Laser Ophthalmoscope (SLO). The rotation parameters are expressed as Y-X-Z Euler angles and in terms of the rotation axis and one rotation angle. Additionally, the angular distance of the retinal stimulus projection can be evaluated relative to the fovea. By simultaneously operating as eye movement measurement device, fundus camera, and visual target projector, the SLO opens a variety of new applications for the combined analysis of eye movements and the underlying 'retinal events' in vision and oculomotor research.

景観の輝度分布に関する研究

A photograph of exterior environment encompassing 120° was taken by an orthographic projection camera, and was converted into the picture of a luminance pattern using colour image processor. In this way the data of luminance in twenty-two natural and artificial landscapes were obtained. Dividing a picture into small areas (about 0.6°) luminance distribution for each scene was plotted as histograms. Based on the shape of histograms, the type of luminance distribution can be classified into four, that is, a natural landscape,, an artificial distant view, an artificial close view and an artificial view with an open plane. Luminance ratios between the adjacent two small areas were then plotted as histograms. This histogram indicates the steepness (or the gentleness) of the slope of brightness, and shows the difference between natural and artificial scenes more clearly. Most luminance ratios for a natural scene are comparatively small, while luminance ratios for an artificial view are either comparatively greater or 1.0 (no contrast). The average of all the luminance ratios between the adjacent two small areas in a picture indicates the harshness (or the flatness) of the total brightness pattern, and differs between natural and artificial scenes. The aver-age of luminance ratios for a natural scene is small, while the average for an artificial view is generally great, with the exception of an artificial view with an open plane. In conclusion, based on the two indices, that is, the steepness of the slope of brightness and the harshness of the total brightness pattern, characteristics of luminance in the exterior environment are satisfactorily explained.

Focus tracking system for direct projection cameras

A focus tracking system for direct wafer steppers has been tested and its operation simulated on computer to account for transducer fabrication limitations. The focus condition of the projection lens was determined by sensing the contrast level in the backprojected image of a test grating object mounted in a plane conjugate to the reticle plane. To permit continuous focus tracking, the test grating was illuminated with red light from a solid-state light emitting diode to prevent exposure of UV-sensitive photoresists. The contrast sensor consisted of a pair of large area silicon photodiodes with grating windows arranged so that the diodes viewed complementary space and bar projected fields of the test grating. The projection lens used in these tests was a 40× microscope objective having a numerical aperture of 0.95. The focus sensing range was found to be better than 1.6 μm, and the focus sensitivity was <0.1 μm.

REPORT ON THE METRIC CAMERA WORKSHOP AT DFVLR OBERPFAFFENHOFEN

AbstractThe Metric Camera workshop was held to discuss results obtained from experiences carried out by principal investigations in the Metric Camera Project. The papers divided into three groups: photogrammetric investigations, interpretation and general. The photogrammetric investigations covered tests of accuracy. Plotting, aerial triangulation and the production of digital elevation modles and orthophotographs. There was general agreement that planimetric accuracies of between 20 m and 30 m and height accuracies of about 30 m could be achieved The emphasis within the group of papers on interpretation was on geology and the maping of cultural features. Results of this work are summarised and discussed in this paper.

An Undergraduate Laboratory Exercise on the Biomechanics of Lifting

Since industrial engineers are responsible for the design of work methods and work stations, undergraduates in this field need to be educated with respect to the biomechanical aspects of lifting; this is most effectively accomplished as part of a required undergraduate ergonomics course. In the Industrial Engineering program at Iowa State University, a required ergonomics course is taught at the sophomore level, prior to a course in work simplification and measurement. A dynamic link segment model has been adapted from its original context in research for use as one of five laboratory exercises in the course. Rapid data acquisition was accomplished using a Graf-Check camera and overhead projection through a grid. Two different lifts were compared in terms of dynamic moments generated in the low back and other areas. The computer output and subsequent analysis permitted a comparison between the two lifting methods as well as a quantitative estimate of effects of handling larger or heavier objects.

The phase-shifting mask II: Imaging simulations and submicrometer resist exposures

Submicrometer optical lithography is possible with conventional projection cameras when the mask controls the phase of the light at the object plane. Two-dimensional imaging simulations for the Mann 4800 projection camera show that the maximum spatial frequency for 60-percent contrast increases from 640 1/mm to 896 1/mm. The geometrical quality of the images of typical microcircuit patterns was shown to be acceptable for feature sizes of 0.7, 0.6, and 0.5 µ, respectively, and various parameters of the irradiance patterns were calculated. Exposures were made using a high-performance two-layer photoresist system and a mask containing patterns similar to those in the simulation. The phase-shifting mask was shown to increase exposure latitude and to produce a 95-percent yield of 833 1/mm (0.6 µ line and gap) patterns, whereas the transmission mask gave a 7-percent yield. Half micrometer features were patterned with a 22-percent yield using 0.436-µ light.

Charge-Coupled Device (CCD) Camera/Memory Optimization For Expendable Autonomous Vehicles

An expendable, autonomous vehicle by definition and implication will require small, low-cost sensors for observation of the outside world, and interface to smart, decision-making avionics. This paper describes results of several interrelated charge-coupled device (COD) camera projects directed toward achieving such an integrated sensor package. A shuttered high-resolution CCD detector combined with a CCD analog frame store memory is described. This system results in a full television (TV) resolution, frame-rate-reduced, deinterlaced image. These image data are suitable for transform or differential pulse-code data compression as well as various other 3 x 3 element operators directed at extracting image intelligence for on-board decision making.

Quantum noise limits the pinspeck camera to simple objects

The pinspeck camera projects a low-contrast image with a great deal of veiling glare. Quantum noise determines that the camera can image only simple objects that contain no more than a few hundred picture elements.

A lens and aperture camera model for synthetic image generation

This paper extends the traditional pin-hole camera projection geometry, used in computer graphics, to a more realistic camera model which approximates the effects of a lens and an aperture function of an actual camera. This model allows the generation of synthetic images which have a depth of field, can be focused on an arbitrary plane, and also permits selective modeling of certain optical characteristics of a lens. The model can be expanded to include motion blur and special effect filters. These capabilities provide additional tools for highlighting important areas of a scene and for portraying certain physical characteristics of an object in an image.

Temporal Bone Scintigraphy: I. Diagnostic Potential in Malignancies of the Ear

The potential value of bone scintigraphy in making the diagnosis and evaluating the prognosis of cancer of the ear, is emphasized and illustrated by results from 6 patients harbouring highly differentiated cancers of the ear. 99Tcm-diphosphonate and special gamma camera projections were used.

Electron-projection microfabrication system

An electron-optical analog of a photon-optical projection camera is described. The system is designed to meet the requirements of future memory technology with submicrometer resolution over a chip size of several millimeters. A self-supporting foil mask is illuminated by electrons and magnetically imaged onto a wafer with a 10×reduction in size. This paper describes the electron optics required for a high-resolution large-field performance. Particular emphasis will be placed on the means for reducing the third-order aberrations of the magnetic projection lenses. The limitations imposed by the unavoidable aberrations of the condenser system are also discussed. The performance of the system is illustrated by reference to results obtained by exposing test patterns.

Generalization of Y-parallax differential formula

A new y-parallax differential formula for inclined photographs has been derived using an orthogonal right-handed frame in stead of an oblique frame on which a projection camera in plotting instruments is mounted. An expressionis found similar to the classic y-parallax equation for vertical photographs.

3) 立體角投射寫眞機の考案とその應用(第4報)

3) 立體角投射寫眞機の考案とその應用(第4報)

9) 立體角投射寫眞機の考案とその應用 (第5報)

9) 立體角投射寫眞機の考案とその應用 (第5報)

14) 立體角投射寫眞機の考案とその應用(第2報)

14) 立體角投射寫眞機の考案とその應用(第2報)

43) 立體角投射寫眞機の考案とその應用(第1報)

43) 立體角投射寫眞機の考案とその應用(第1報)