Synthetic vision-a view in the fog

Burgess, Malcolm A.; Hayes, R. D.

doi:10.1109/dasc.1992.282093

Cited by 11 publications

(5 citation statements)

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“…The idea of using HUDs as an Augmented Reality device was originally introduced and explored for avionic applications [15,10,9,21]. Here, pilots are assisted in navigating the plane safely in the air or on the ground by visualizing flight corridors or by highlighting taxiways when the visibility is low.…”

Section: Introductionmentioning

confidence: 99%

A camera-based calibration for automotive augmented reality Head-Up-Displays

Wientapper

Wuest

Rojtberg

et al. 2013

2013 IEEE International Symposium on Mixed and Augmented Reality (ISMAR)

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Using Head-up-Displays (HUD) for Augmented Reality requires to have an accurate internal model of the image generation process, so that 3D content can be visualized perspectively correct from the viewpoint of the user. We present a generic and cost-effective camera-based calibration for an automotive HUD which uses the windshield as a combiner. Our proposed calibration model encompasses the view-independent spatial geometry, i.e. the exact location, orientation and scaling of the virtual plane, and a view-dependent image warping transformation for correcting the distortions caused by the optics and the irregularly curved windshield. View-dependency is achieved by extending the classical polynomial distortion model for cameras and projectors to a generic five-variate mapping with the head position of the viewer as additional input. The calibration involves the capturing of an image sequence from varying viewpoints, while displaying a known target pattern on the HUD. The accurate registration of the camera path is retrieved with state-of-the-art vision-based tracking. As all necessary data is acquired directly from the images, no external tracking equipment needs to be installed. After calibration, the HUD can be used together with a head-tracker to form a head-coupled display which ensures a perspectively correct rendering of any 3D object in vehicle coordinates from a large range of possible viewpoints. We evaluate the accuracy of our model quantitatively and qualitatively

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Section: Introductionmentioning

confidence: 99%

A camera-based calibration for automotive augmented reality Head-Up-Displays

Wientapper

Wuest

Rojtberg

et al. 2013

2013 IEEE International Symposium on Mixed and Augmented Reality (ISMAR)

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“…Thus depending on the fog drop sizes and concentrations, the fog NIR attenuation can vary from 0.2dB/km in exceptionally clear weather, to 310 dB/km in very dense fog. 6,7 Most fog droplets have radii ranging from 5 to 15 µm 2 which is comparable to the wavelength of NIR radiation when the value of the scattering cross section is near its maximum. It follows that the transmission through fog in either the visible or IR spectral regions is poor for any reasonable path length.…”

Section: Introductionmentioning

confidence: 99%

“…[6][7][8][9] In the extensive experimental study Clay and Lenham (1981) 10 showed that in the earlier stages of development of all the fogs studied the attenuation is smallest at longer wavelengths -indicating the predominance of small droplets. As fog deepened, some of the fogs developed attenuation curves that showed a maximum attenuation in the 1-4µm range of wavelengths.…”

Section: Introductionmentioning

confidence: 99%

<title>Wavelength and altitude dependence of laser beam propagation in dense fog</title>

Калашникова

Willebrand

Mayhew

2002

Free-Space Laser Communication Technologies XIV

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The availability of free-space laser communications systems critically depends upon estimating the accuracy of atmospheric attenuation in different weather conditions. Fog and extreme rain are the primary types of weather that can affect shorter wavelength laser communication links. Traditionally, designers and users of free-space laser communication equipment assumed that light suffers from less atmospheric attenuation at longer infrared wavelengths such as 1.55µm and 3.5µm compare to 0.85µm. Thought, as some experimental studies show, it is not safe to assume that the performance of detection systems in IR is always better in fogs than at visual wavelengths. In dense stages in long persisting fogs the attenuation at longer wavelengths often becomes large, or even larger, than that in the visible. To investigate performance of laser systems in the dense fog, we ran extensive MODTRAN calculations of atmospheric transmission for the different types of dense fog at visible-IR range of wavelengths. Our results show that an atmospheric attenuation in such fogs slightly increases with wavelength in the range 0.5-4 µm and then decreases with the longer wavelengths. This is in contrast with widely used parameterization that states decreasing of the fog attenuation beyond visible. To investigate this further, we used concentrations and size distributions data collected in dense persisting fogs at different altitudes, and performed Mie scattering calculations. We determined fog extinction in a range of altitudes (10-100m) and at four wavelengths used in free-space communication: 0.85µm, 1.55µm, 3.5µm and 10.6 µm. We found that atmospheric attenuation in dense fog sharply increases with altitude, slightly increases at 3.5µm compared to 0.85µm and then decreases at 10.6 µm.

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“…The additional advantage of such a system is that, it will be able to operate from airports which are not equipped with the ground based ASTA system. The following sensors are envisioned for this system: X-Band radar, Millimeter Wave active radar, video and Infrared cameras and low-light TV [1,4]. Outputs of these sensors will be integrated with GPS/INS information and airport geometry database to locate the aircraft within the airport, detect obstacles, determine potential conflicts, issue advisories and sound cockpit alarms.…”

Section: Introductionmentioning

confidence: 99%

<title>Computer-aided system for detecting runway incursions</title>

Sridhar

Chatterji

1994

SPIE Proceedings

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A synthetic vision system for enhancing the pilots ability to navigate and control the aircraft on the ground is described. The system uses the onboard airport database and images acquired by external sensors such as, millimeter wave, infra-red and low light TV cameras. Additional navigation information needed by the system is provided by the Inertial Navigation System and the Global Positioning System. The various functions of the system such as, image enhancement, map generation, obstacle detection, collision avoidance, guidance etc., are identified. The available technologies, some of which were developed at NASA that are applicable to the aircraft ground navigation problem, are noted. Example images of a truck crossing the runway while the aircraft flies close to the runway centerline are described. These images are from a sequence of images, acquired during one of the several flight experiments conducted by NASA to acquire data to be used for the development and verification of the synthetic vision concepts. These experiments provide a realistic database including video and infra-red images, motion states from the Inertial Navigation System and the Global Positioning System, and camera parameters.

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Synthetic vision-a view in the fog

Cited by 11 publications

References 0 publications

A camera-based calibration for automotive augmented reality Head-Up-Displays

A camera-based calibration for automotive augmented reality Head-Up-Displays

<title>Wavelength and altitude dependence of laser beam propagation in dense fog</title>

<title>Computer-aided system for detecting runway incursions</title>

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