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The optical effect of atmospheric turbulence greatly inhibits the achievable range of Detection, Recognition and Identification (DRI) of targets when using imaging sensors within the surface layer. Since turbulence tends to be worst near the ground and decays with height, the question often arises as to how much DRI range could be gained by elevating the sensor. Because this potential DRI gain depends on the rate of decay of turbulence strength with height in any particular environment, there is a need to measure the strength profile of turbulence with respect to height in various environments under different atmospheric and meteorological conditions. Various techniques exist to measure turbulence strength, including scintillometry, sonic anemometry, Sound Detection and Ranging (SODAR) and the analysis of point source imagery. These techniques vary in absolute sensitivity, sensitivity to range profile, temporal and spatial response, making comparison and interpretation challenging. We describe a field experiment using multiple scintillometers, sonic anemometers and point source videography to collect statistics on atmospheric turbulence strength at different heights above ground. The environment is a relatively flat, temperate to sub-tropical grassland area on the interior plateau of Southern Africa near Pretoria. The site in question, Rietvlei Nature Reserve, offers good spatial homogeneity over a substantial area and low average wind speed. Rietvlei was therefore chosen to simplify comparison of techniques as well as to obtain representative turbulence profile data for temperate grassland. A key element of the experimental layout is to place a sonic anemometer 15 m above ground at the centre of a 1 km slant-path extending from ground level to a height of 30 m. An optical scintillometer is operated along the slant-path. The experiment layout and practical implementation are described in detail and initial results are presented.

The current widespread use of webcams for personal video communication over the Internet suggests that opportunities exist to develop video communications systems optimized for domestic use. We discuss both prior and existing technologies, and the results of user studies that indicate potential needs and expectations for people relative to personal video communications. In particular, users anticipate an easily used, high image quality video system, which enables multitasking communications during the course of real-world activities and provides appropriate privacy controls. To address these needs, we propose a potential approach premised on automated capture of user activity. We then describe a method that adapts cinematography principles, with a dual-camera videography system, to automatically control image capture relative to user activity, using semantic or activity-based cues to determine user position and motion. In particular, we discuss an approach to automatically manage shot framing, shot selection, and shot transitions, with respect to one or more local users engaged in real-time, unscripted events, while transmitting the resulting video to a remote viewer. The goal is to tightly frame subjects (to provide more detail), while minimizing subject loss and repeated abrupt shot framing changes in the images as perceived by a remote viewer. We also discuss some aspects of the system and related technologies that we have experimented with thus far. In summary, the method enables users to participate in interactive video-mediated communications while engaged in other activities.

We show bubbles investigated with videography and multiple colour LED flash illumination. The short flashes show the propagation and development of the shape of the bubbles. The long flashes make the velocity vector of the bubbles directly visible and allow easy investigation of the unstable movement. If bubbles are used to reduce friction of ships, then it is effective to spread the gas volume over lots of micro bubbles. Another experiment is the investigation of the noise of a bass reflex loud-speaker. The visualisation of air flow shows linear behaviour at low power and a previously unknown effect at high power - continuous streaming of air in the bass reflex tube.

High-speed imaging and cinematography are important in research on explosions, firearms, and homeland security. Much can be learned from imaging the motion of shock waves generated by such explosive events. However, the required optical equipment is generally not available for such research due to the small aperture and delicacy of the optics and the expense and expertise required to implement high-speed optical methods. For example, previous aircraft hardening experiments involving explosions aboard full-scale aircraft lacked optical shock imaging, even though such imaging is the principal tool of explosion and shock wave research. Here, experiments are reported using the Penn State Full-Scale Schlieren System, a lens-and-grid-type optical system with a very large field-of-view. High-speed images are captured by photography using an electronic flash and by a new high-speed digital video camera. These experiments cover a field-of-view of 2x3 m at frame rates up to 30 kHz. Our previous high-speed schlieren cinematography experiments on aircraft hardening used a traditional drum camera and photographic film. A stark contrast in utility is found between that technology and the all-digital high-speed videography featured in this paper.

Air Force Research Laboratory and MetroLaser, Inc. researchers have completed the initial development and transition to operational use of portable field holography systems. This paper documents the first fully operational use of a novel and unique experimental capability for remote field holography. In this paper we document the field trials and initial experiments that were performed with the Remote Holographic Interferometry System (RHIS) at the Munitions Directorate, Air Force Research Laboratory Site at Eglin, AFB, Florida. These experiments were performed to assess the effectiveness of remote pulsed laser holography combined with high-speed videography to document the formation and propagation of plumes of materials created by impact of high-speed projectiles. This paper details the development of the experimental procedures and initial results of this new tool.

Light emitting diodes are very efficient sources of visible and infared light. They have small size and can be combined with fiber optical cables easily. Simple videography can use the wavelength range 400 nm - 1000 nm, which is covered totally by the LED. The speed of modern LED allows flashes shorter than 100 ns in the whole spectral range.

Model MD-1 CCD Micro High-speed Videography System recently developed in Zhejiang University endeavors to apply high speed strobe videography method to micro domain. Computer controlled high speed Xenon pulses are flashed to illuminate moving micro objects. Image sequences of the moving micro objects are recorded in one frame by a CCD video camera and transferred to the computer to be reviewed, processed and stored. The system is characterized by the ability to analyze object dynamics of micrometer level with the highest magnification rate of 15,000 times, the highest 'freezing' ability of several microseconds and the highest image capture frequency of 33,000 IPS (images per second). Principles, hardware and software compositions and applications of the system are illustrated in this paper as well as the multi-beam condenser, a specially designed micro illumination device to obtain a uniform, well-balanced bright field in experiments.

The paper deals with our research on developing videogrammetry based 3D modeling procedure for indoor facilities. The modeling is based on recorded video sequences, and the analysis procedure is reverse if compared to the traditional one. Here a functional 3D model is built first and the measurements for exact geometry are done thereafter: `Modeling first--then measuring'. The final output will be a photorealistic model.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A novel CCD high speed videography system with brand-new concepts and techniques is developed by Zhejiang University recently. The system can send a series of short flash pulses to the moving object. All of the parameters, such as flash numbers, flash durations, flash intervals, flash intensities and flash colors, can be controlled according to needs by the computer. A series of moving object images frozen by flash pulses, carried information of moving object, are recorded by a CCD video camera, and result images are sent to a computer to be frozen, recognized and processed with special hardware and software. Obtained parameters can be displayed, output as remote controlling signals or written into CD. The highest videography frequency is 30,000 images per second. The shortest image freezing time is several microseconds. The system has been applied to wide fields of energy, chemistry, medicine, biological engineering, aero- dynamics, explosion, multi-phase flow, mechanics, vibration, athletic training, weapon development and national defense engineering. It can also be used in production streamline to carry out the online, real-time monitoring and controlling.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

g1-andersonpop.tamu.eduABSTRACTResearchers are expending considerable effort to develop the technology and methodology needed to identify and map within-field management zones for site-specific farming. Much of the research has focused on the use of either a high-densitygeographically referenced grid of soil samples or mechanical yield sensor measurements that record geographic positions andproduction levels. In either case, complex spatial models are generally used to extrapolate the various soil variables andproduction level information across the entire field. Both procedures produce a wealth of information, however, the analysisofsoil samples tends to be quite expensive and the accuracy ofmechanical yield measurements does vary. This study representsan ongoing effort designed to evaluate remote sensing as a tool for determining within field management zones. Color-infraredaerial photography and multispectral videography were used in concert to map and stratify two grain sorghum fields into regionsor zones ofhomogeneous spectral response. A limited number ofsoil and plant samples were acquired to characterize the bioticand edaphic conditions within each zone. Results obtained during the first year ofthe study indicated that multispectral videocan be used to develop within field management zones. Simple univariate analysis indicated that siol pH, Ca, and Fe wereimportant variables affecting yield. Analysis ofthe yield data indicated that the economic returns from 17 % ofthe first fieldand 20 % ofthe second field were insufficient to recoup planting costs. Multispectral video also proved instrumental in modelingthe spatial variability ofyield. A significant negative correlation (r>O.9O) was obtained between the red spectral band and cropyields for both fields. Stratification, in this case using image data, reduces the number ofsamples required to characterize a fieldby reducing the variance associated within each stratum. Image data also provided a comprehensive view of each field thatmaintained the spatial connectivity between sites, thus reducing the need for complex spatial modeling.Keywords: multispectral videography, precision fanning, sorghum, GIS, OPS, remote sensing, yield1. INTRODUCTIONConsiderable research is being conducted to develop the technology and methodology for managing agricultural fields ona site-specific basis. This research centers around automatic real-time control and temporally separate control of agriculturalinputs to specific sites within a field .

A questionnaire was distributed to scientists and engineers all over Japan to compile information on conventional and potential application of high-speed videography and special conditions associated with using them in practice. The distribution of the required frame rate shows that existing high-speed videocameras of 103 to 104 pps cover only 30-40% of the potential usages, while existing image-converter multiframing cameras of 106 to 107 pps cover more than 90%. It is, however, clear from the authors' experiences that dynamic recognition, which is supported by videocameras but not by multiframing cameras, is an essential and very powerful tool in scientific and engineering research. New concepts to produce high-speed videocameras of 105 to 107 pps are therefore presented.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A videography system is introduced and its ability in catching image of high speed projectile is shown. This microcomputer-based system consists of two optical gates, a CCD camera, a frame grabber, a flash lamp and some ancillary electronics. The optical gates are accompanied with some electronic circuits to provide accurate timing for image catching, and the frame grabber provides real time process capability for image processing.

The ability to image high velocity projectiles requires a precise trigger, short gate periods and known timing data for performance measurement. Data analysis software provides a means for data reduction to useable numerical ballistic parameters. The software relies on knowns of image format, image frame rate, gate period, and timing data for its analytical capability. Prior to applying the software to the data analysis task, the basics of image capture and data annotation must be established to provide a suitable basis for software analysis of ballistic performance. Empirical data can be obtained through the use of simple tools to properly understand the image capture dynamics and establish a precise basis for ballistic analysis.

Over the years `synchro-ballistic' photographic techniques have been used to aid the scientist and engineer in obtaining data of fast moving events. With the availability of `gated video' a new technique, `Ballistic Videography' has emerged. The purpose of this discussion is to review the principles of synchro-ballistic photography and discuss the use of high speed gated video to simplify and increase date yield.

High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100 microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

Within industrial off-line applications the complete 3-D digitizing of object surfaces willbe performed using stereo videography. Typical examples where the off-line measure-ments are needed, are: 1) the reverse engineering during the industrial design; and 2)the quality control during the process setup. In both cases the measuring tasks areless time constrained than in the case of the on-line control. On the contrary, therequirements are higher as it regards the completeness of the recovered object modeland the accuracy of the object measures.Within the paper an off-line 3-D measuring procedure is discussed. The procedure isunder development in a project which belongs to the national research programme onmachine vision in Finland 1992-1996. The procedure consists of four concurrentphases: 1) recording, 2) rectification, 3) digitizing, and 4) modelling. The recordingsare based on sequential stereo videography and the continuous object digitizing isbased on the rigid normal case of stereography. The system modules are: 1) the two

The goal of sport biomechanists is to provide information to coaches and athletes about sport skill technique that will assist them in obtaining the highest levels of athletic performance. Within this technique evaluation process, two methodological approaches can be taken to study human movement. One method describes the motion being performed; the second approach focuses on understanding the forces causing the motion. It is with the movement description method that video image recordings offer a means for athletes, coaches, and sport biomechanists to analyze sport performance. Staff members of the Technique Evaluation Program provide video recordings of sport performance to athletes and coaches during training sessions held at the Olympic Training Center in Colorado Springs, Colorado. These video records are taken to provide a means for the qualitative evaluation or the quantitative analysis of sport skills as performed by elite athletes. High-speed video equipment (NAC HVRB-200 and NAC HSV-400 Video Systems) is used to capture various sport movement sequences that will permit coaches, athletes, and sport biomechanists to evaluate and/or analyze sport performance. The PEAK Performance Motion Measurement System allows sport biomechanists to measure selected mechanical variables appropriate to the sport being analyzed. Use of two high-speed cameras allows for three-dimensional analysis of the sport skill or the ability to capture images of an athlete's motion from two different perspectives. The simultaneous collection and synchronization of force data provides for a more comprehensive analysis and understanding of a particular sport skill. This process of combining force data with motion sequences has been done extensively with cycling. The decision to use high-speed videography rather than normal speed video is based upon the same criteria that are used in other settings. The rapidness of the sport movement sequence and the need to see the location of body parts of the athlete, particularly at critical positions during the motion, serve as guidelines for choosing high-speed videography. Certain requirements for high-speed videography need to be considered in selecting appropriate equipment. These include portability, genlock capability, weight, sturdiness, and costs.

This paper discusses the design of a multispectral radiometer and camera implemented using a CCD imager, two Silicon photodiode radiometers and a rotating filter wheel equipped with six bandpass filters spaced throughout the visible and near-IR spectrum. One of the radiometers has a field-of-view matched to that of the camera to measure integrated scene radiance, whereas the other radiometer functions as a spot radiometer to measure small surface radiances. The system is synchronized with the 60 Hz camera video and transfers the 16-bit digitized data from the two radiometers once every video field through a parallel interface to a video data encoder. The encoder incorporates the data into the current video field for VCR recording and later playback and analysis. The system is designed for airborne use mounted underneath the wing of an aircraft. Its main purpose is to analyze the spectral radiances of various surfaces involved in high-speed videography experiments. The data obtained with the radiometer will be used to refine specifications for a high-speed, high-resolution solid state imager. However, applications extend to any field where fast, spectral measurements are required. A data set obtained for a sample application is presented to illustrate the performance of the system.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Natural color (NC) and color infrared (CIR) video systems were used to acquire oblique and near-nadir imagery of citrus grove areas that were damaged by cold temperatures during the nights of February 25 and 26, 1989. Two flights were made 10 days apart from 9:30 am to 12:00 noon each day at 100 m and 300 m altitudes. The video cameras adjusted to the changing light intensity caused by cloud interference and turbulent weather and produced acceptable images for the detection of freeze damage and delineation of damaged areas. The contrast between green and brown video images was less distinctive than the contrast between cyan and magenta of the CIR video. Both NC and CIR video cameras captured images of damaged citrus trees, but it was not possible to measure the areas with an image analysis system because images were oblique and were acquired in different overflights of the damaged areas. The major benefits derived from videography were instant acquisition and viewing of images, rapidly locating damaged areas, and determining that all sites were imaged.

In the past, analysis of flame propagations within a spark ignition engine combustion chamber has been analyzed with pressure diagrams. These pressure diagrams have helped to develop the geometry within the combustion chamber. Photographing or electronically imaging the flame propagations are very important in the visualization of combustion characteristics. Attempts to use intensification with videography have met with limited success. A new integrated intensified imager is now available which works in conjunction with the KODAK EKTAPRO 1000 Motion Analyzer. The intensified imager to be discussed uses a two stage intensifier coupled to a solid-state sensor array. The first stage shutters the image at microsecond rates. The second stage amplifies the light from the first stage over a short integration period. The coupling of these two stages to Kodak's 1000 frame per second motion analyzer has significantly extended the use of high speed videography for flame propagation studies. This paper will address the imaging requirements for flame propagation studies and the methods for performing analysis using an intensified imager.

The demand for clarifying high speed phenomena exists widely. Conventionally, researchers and engineers have relied on high-speed cinematography (HSC) but the recent trend is foward greater use of high-speed videography (HSV) in many fields. HSV, when compared to HSC, admittedly, has some drawbacks, but it has advantages that more than outweigh such drawbacks. Because of these advantages, wider acceptance of HSV is expected. In this paper, recent cases of applications of HSV are introduced.

All major specialty areas of the high speed photography and photonics field have experienced rapid development during the past two years and may be expected to continue to do so. ,Intelligent film annotation devices promise to make a major impact upon the applications of pin registered cameras. The advent of color and ultra high speed videography promise other rapid advances. Rotating prism cameras should shortly enjoy advantages of modern film annotation. Top speeds of 16mm reel-to-reel cameras should be extended well beyond 10,000 fps. in the near future. Full use of beryllium as a rotating mirror material for modern cine' and framing cameras is increasing performance capabilities markedly. Emphasis in the development of electronic cameras is shifting toward enhancement of information content of individual records and making cameras more responsive to particular experimental needs. Finally, two new technologies, high speed holography and pulsed laser cinematography show promise of becoming important new technology areas of their own within the near future.

High-speed videography (HSV) at 60 frames-per-second (FPS) has since the earliest systems been an attractive goal. Vast numbers of information gathering and motion analysis problems lend themselves to solution at this rate. Seemingly suitable equipment to implement inexpensive systems has been available off-the-shelf. However, technical problems, complexity and economic factors have pushed development toward higher frame rate systems. The application of new technology recently has combined with a shift of the perceived needs of mass (security and consumer) markets to make available the components for truly inexpensive, high-performance 60 FPS HSV systems. Cameras employing solid-state sensors having electronic shuttering built into the chip architecture are widely available. They provide a simple solution to the temporal resolution problem which formerly required synched/phased mechanical shutters, or synchronized strobe illumination. More recently, the crucial need for standard-format (such as VHS) videocorders capable of field sequential playback in stopped- or in slow-motion has been satisfied. The low cost of effective 60 FPS systems will likely be an incentive for a dramatic increase in the general awareness of the power of HSV as a problem-solving tool. A "trickle-up" effect will be to substantially increase the demand for higher performance systems where their characteristics are appropriate.

Special video path editing capabilities with custom hardware and software, have been developed for use in conjunction with existing video acquisition hardware and firmware. This system has simplified the task of quantifying the kinematics of human movement. A set of retro-reflective markers are secured to a subject performing a given task (i.e. walking, throwing, swinging a golf club, etc.). Multiple cameras, a video processor, and a computer work station collect video data while the task is performed. Software has been developed to edit video files, create centroid data, and identify marker paths. Multi-camera path files are combined to form a 3D path file using the DLT method of cinematography. A separate program converts the 3D path file into kinematic data by creating a set of local coordinate axes and performing a series of coordinate transformations from one local system to the next. The kinematic data is then displayed for appropriate review and/or comparison.© (1988) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

One of the most challenging areas in applying high-speed photography and videography in the plant and laboratory is in the recording of rapid events at macro and microscopic scales. Depth of field, exposure efficiency, working distance, and required exposure time are all reduced as optical magnification is increased, which severely taxes the skill and ingenuity of workers interested in recording any fast moving phenomena through the microscope or with magnifying lenses. This paper defines the problems inherent in photographing within macro and microscopic ranges and offers a systematic approach to optimizing the selection of equipment and choice of applicable techniques.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Instrumentation Technology Branch of the Air Force Armament Laboratory is currently involved in the development of several high speed photographic, videographic, and photonic instrumentation systems to support the testing and analysis of developmental weapons and test items under dynamic conditions. These projects include development of a large format (14 inch by 17 inch) laser illuminated Cranz-Schardin shadowgraph system for materials research, development of a solid state imager based shadowgraph system for aeroballistic studies, experiments with gated imagers for a variety of test applications, and experiments with high speed video imagers and illuminators for airborne and range tracking instrumentation. An additional issue discussed is the development of a timing and annotation standard for video imaging instrumentation systems operating at higher than NTSC standard rates.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

For over half a century High Speed Motion Picture Photography has provided a unique opportunity to analyse fast movements in industrial machinery and processes.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The field of high-speed videography (HSV) has continued to mature in recent years, due to the introduction of a mixture of new technology and extensions of existing technology. Recent low frame-rate innovations have the potential to dramatically expand the areas of information gathering and motion analysis at all frame-rates. Progress at the 0 - rate is bringing the battle of film versus video to the field of still photography. The pressure to push intermediate frame rates higher continues, although the maximum achievable frame rate has remained stable for several years. Higher maximum recording rates appear technologically practical, but economic factors impose severe limitations to development. The application of diverse photographic techniques to video-based systems is under-exploited. The basics of HSV apply to other fields, such as machine vision and robotics. Present motion analysis systems continue to function mainly as an instant replay replacement for high-speed movie film cameras. The interrelationship among lighting, shuttering and spatial resolution is examined.

The unaided human eye with its inherent limitations serves us well in the examination of most large-scale, slow-moving, natural and man-made phenomena, but constraints imposed by inertial factors in the visual mechanism severely limit our ability to observe fast-moving and short-duration events. The introduction of high-speed photography (c. 1851) and videography (c. 1970) served to stretch the temporal limits of human perception by several orders of magnitude so critical analysis could be performed on a wide range of rapidly occurring events of scientific, technological, industrial, and educational interest. The preferential selection of eye, film, or video imagery in fulfilling particular motion analysis requirements is determined largely by the comparative attributes and limitations of these methods. The choice of either film or video does not necessarily eliminate the eye, because it usually continues as a vital link in the analytical chain. The important characteristics of the eye, film, and video imagery in high-speed motion analysis are discussed with particular reference to fields of application which include biomechanics, ballistics, machine design, mechanics of materials, sports analysis, medicine, production engineering, and industrial trouble-shooting.

Traditionally movie film has been the major medium by which investigators have analyzed, described and quantified the temporal and spatial characteristics of human motion. In addition, movie film has been used to estimate the forces resulting from the acceleration of the human body and its parts. Predictions of muscle force and reactive forces at the joints have also been made based upon film analysis. Although high speed filming was described as early as 1910, its use in the study of human motion was primarily from the 1960's onward. Filming at rates greater than 24 frames per second (fps) technically can be considered high speed. Most of the early human motion analysis was conducted using cameras operating at not greater than 128 fps, usually at 64 fps. These were relatively inexpensive cameras. The ultra-high speed cameras, however, were used to some extent during the early 1960's and became standard equipment in the well equipped University Biomechanics Laboratories for human motion analysis in the 1970's. As early as 1970 there were no fewer than four cameras capable of operating at speeds greater than 1000 fps. Cost, lack of comparable sophistication in analysis techniques, and operating complexities were primary factors in these ultra high speed cameras not being used to study human motion prior to the late 1970's. Human motion, even now, is usually recorded with cameras operating between 60 and 250 frames per second.

High-speed videography has been an electronic analog of low-speed film cameras, but having the advantages of instant-replay and simplicity of operation. Recent advances have pushed frame-rates into the realm of the rotating prism camera. Some characteristics of videography systems are discussed in conjunction with applications in sports analysis, and with sports equipment testing.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.