Aerial Photography: A Comprehensive Survey of Its Practice & DevelopmentBeskriver luftfotograferingens historiske udvikling. |
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Common terms and phrases
adjustment aerial camera aerial photography aerial survey Aero Aerofilms aeroplane air survey aircraft Alexander Keiller altitude angle aperture apparatus archæologist Autocartograph automatic axis bromide camera body carried centre colour cone contact prints course covered density detail distance drift Eastman Eastman Kodak effect electrical emulsion enlargement face Fairchild Fairchild Aerial Surveys feet filter fitted fixed flying focal length focal plane shutter frame glass grain ground surveyor haze height horizontal inches lens lenses light loaded magazine lynchets machine magazine manufacturers means method mosaic mounting necessary negative number of exposures O. G. S. Crawford objects oblique photographs obtained operation optical ordinary overlap photographic map pilot plate or film plotting position possible prints projection rays recorded Royal Air Force scale screen sensitive sight slide slit speed square miles stereoscopic strips taken tanks tilt vertical photographs wind
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Page 158 - This proved to be oil. An investigation resulted in tracing the oil to a broken pipe line on the river bottom. No factory or plant using the waterway for illegal sewage disposal purposes can avoid the eye of the aerial camera.
Page 113 - ... has speed and time scales marked on it, while drift wires at the sides carry timing-beads. The position of the drift bar is adjusted to the true air speed by means of a milled nut, while a quadrant drift scale, over which the tail of the drift bar moves indicates the angle of drift. The height bar is hinged at its base and when not in use can be folded down. To use the instrument, the bearing plate is turned until the lubber mark points to the course being steered ; the drift bar is then turned...
Page 158 - ... and begins with general unconvincing statements like "By methods which are being improved by our scientists every day, it has become possible to contour economically from the air." The best chapter is that on Industrial and Municipal Application of Aerial Photography; but it is hard to believe that "the owner of a famous nursery at Amawalk-on-the-Hudson was able to secure in one photograph, a complete portrayal of all the species and foliage, actual number of the 350,000 trees, and their height....
Page 176 - Sunday — going to inspect some suspicious circular markings visible on an air-photograph near Winchester. They might have been a group of barrows ; actually they were due to the circular browsing of tethered goats ! Fungus rings also mislead the unwary. I hasten to add that the examples which have been used to illustrate this lecture have been checked by personal inspection and found satisfactory. To reap the best results there is needed only a large number of airphotographs of regions which are...
Page 45 - coffee,' then, there entered, to the relief of the young man, four strangers; but, before introducing these to notice, it may be as well to say a word or two about that gallant officer himself, for he is the true hero of this my story. Mr Arthur Wellesley Woolley was the only son of a London citizen, of credit as good as Gilpin's, though he was by no means of so much renown. Mr Arthur Wellesley Woolley was...
Page 190 - ... lenses which are combinations of four simple lenses. These are the types of lenses used in many aerial cameras. Fig. 6. A diagram to show how the focal length of a lens is measured. As focal length is to height so is the width or length of plate to the width or length of the ground covered. The scale is therefore directly proportional to the focal length and inversely proportional to the altitude. f = focal length of the lens, h = height at which photo is taken, w = width or length of plate in...
Page 189 - ... 1 inch on the map represents 21,120 inches or one-third of a mile on the ground ; or 3 inches represents 1 mile. ' (c) By 9raphical scale, that is, a line drawn on the map, divided into equal parts, each part being marked with the distance that it represents on the ground. (1) To find the number of miles to the inch for any map that has a RF, divide the denominator of the RF by 63,360; thus, if RF is 1/80,000, then 80,000/63,360=1.263 miles to the inch. (2) To find the number of inches to the...
Page 208 - INDICATED. 7'o face puge 213. easily distinguished at a distance of forty miles or more, from an elevation of five thousand feet. The sketch maps now in existence show these points, together with a vague outline of shore, and very little more. It is just here that the air traveller gets one of his greatest advantages over the man on the ground. The latter cannot jump from one easily identified point to the next, often many miles distant, but must follow the water course in all its intricate details.
Page 114 - Turn bearing plate until the lubber mark points to the course being steered. Turn drift bar (D) until it is parallel to the earth drift, best noted by sighting on the new position of some object over which the machine was observed to have passed some minutes before (or on a dropped flare). Draw a line on the glass along the bevelled edge of the drift bar, using a glass-marking pencil.
Page 115 - ... of the two lines then determines the " wind point " ; the reading on the black scale of the drift bar opposite the wind point will give the ground-speed, while the red scale will show the number of minutes to cover 30 miles. At any time during this operation, the quadrant drift scale near the pivot will give the drift angle in degrees, which added to or subtracted from the course steered will give the course made good. Inv. 1923-1112 299. AERO BEARING PLATE. Lent by the Air Ministry, 1921. This...