- 업종: Aerospace
- Number of terms: 16933
- Number of blossaries: 2
- Company Profile:
The Executive Branch agency of the United States government, responsible for the nation's civilian space program and aeronautics and aerospace research.
(1) The solid angle through which a detector is sensitive to radiation. In a scanning system this refers to the solid angle subtended by the detector when the scanning motion is stopped. instantaneous field of view is commonly expressed in milliradians. (2) The ground area covered by this solid angle. See ground resolution cell.
Industry:Aerospace
(1) To align the axes of instruments, especially optical axes of multiple lenses, so that they have the same spatial orientation along a common line. (2) To make parallel rays of light by means of a lens or concave mirror.
Industry:Aerospace
(1) To restrict a variable to discrete values, each of which is normally an integral multiple of the same quantity. (2) To process a range of grey shades, from maximum to minimum, such that the entire range is divided into contiguous intervals of normally equal lengths, each being assigned an integer value unique to the grey shade corresponding to it. Output voltages from the ETM+ and TM sensors aboard Landsat 4, 5 and 7 are quantized into 256 discrete values prior to transmission to the ground. A total of 256 brightness values are therefore possible in each band of ETM+ and TM imagery.
Industry:Aerospace
(Landsat usage) A number in a range of 0-63, 0-127, or 0-255 that is related to the amount of radiance in watts per square centimeter striking a detector in either the Multispectral Scanner, the Thematic Mapper, or the Enhanced Thematic Mapper Plus.
Industry:Aerospace
A color image produced by the combination of (usually) three individual monochrome images each of which is reproduced in a given color. With Landsat TM and ETM+ imagery, a natural color image is created by assigning the color blue to band 1 (0.45-0.52 µm), green to band 2 (0.52-0.60 µm), and red to band 3 (0.63-0.69 µm).
Industry:Aerospace
A color image produced by the combination of (usually) three individual monochrome images each of which is reproduced in a given color. With Landsat TM and ETM+ imagery, a natural color image is created by assigning the color blue to band 1 (0.45-0.52 µm), green to band 2 (0.52-0.60 µm), and red to band 3 (0.63-0.69 µm).
Industry:Aerospace
A device for producing light by emission of energy stored in a molecular or atomic system when stimulated by an input signal.
Industry:Aerospace
A digital image, or digitized image, or digital picture function of an image, is an image represented numerically in digital form and is obtained by partitioning the area of the image into a finite two-dimensional array of small, uniformly shaped, mutually exclusive regions, called resolution cells or picture elements (pixels), and by assigning a representative grey shade to each such spatial region. A digital image may be abstractly thought of as a function whose domain is the finite two-dimensional set of resolution cells and whose range is the set of grey shades.
Industry:Aerospace
A disturbance which is propagated in a medium in such a manner that at any point in the medium the quantity serving as the measure of the disturbance is a function of time, while at any instant the displacement at a point is a function of the position of the point. Any physical quantity having the same relationship to some independent variable (usually time) that a propagated disturbance has, at a particular instant, with respect to space, may be called a wave. An electromagnetic wave is one in which the disturbance is the change in the electric and magnetic field intensities from their equilibrium values in space.
Industry:Aerospace
