B
band or spectral band
A range of wavelengths of electromagnetic radiation. Remote sensing devices commonly collect images in discrete bands, such as visible red, green, and blue, and the invisible near-infrared.
band seperate
An image format that stores each band of data collected by multispectral satellite scanning instuments in a seperate file.
band width
A measure of the volume of data that can flow through a communications link. image data tend to exist as large datasets; thus moving image data sets from one computer to another requires high bandwidth or performance will be slowed. Also known as through put.
base maps
A map containing visible surface features and boundaries, essential for locating additional layers or types of georeferenced information.
batch
(DOS) A DOS batch file is a text file with the extension .BAT that contains one DOS command on each line. When you enter the name of the batch file at the DOS prompt, the system performs each command in turn.
Bézier curve
A polynomial curve bounded by four points, which form a "bounding box." Manipulating the position of the bounding points lets a user stretch and position a smooth curved line in the design of a graphic shape, such as the irregular curving outline of a font character.
bilinear interpolation
A mathematical method for interpolating a new cell's value within a 2 x 2 neighborhood of cells. Bilinear interpolation is used in resampling a raster object to create a new raster object with a different cell size, orientation, or internal geometry. (See also: interpolation.)
binary
A base 2 number system that uses only the data values "0" and "1." Each place represents a power of 2, so, for example, the decimal number 6 is represented in base 2 as 110 (= 1x4 + 1x2 + 0x1).
binary raster object
A raster whose cells contain only the values "0" (typically displayed as black) or "1" (white). Binary raster objects usually store a scan of black lines on white paper, the results of thresholding a byte-oriented raster object into two data ranges, a threshold of a particular color range, or a data mask.
biomass or total biomass or total plant material
The amount of plant material per unit of ground area, recorded either as wet weight or dry weight. It is usually expressed in grams per square meter, tons per acre, or metric tons per hectare.
bit
The smallest unit of information that a computer can store and process. A bit has two possible values, 0 or 1 which can be interpreted as yes/no, true/fals or on/of.
bitmapped font
A font specification in which each character is described pixel by pixel for a particular font size. Thus, bitmapped fonts do not rescale easily: at smaller sizes, pixels are left out, and at larger sizes, pixel reduplication causes a jagged, blocky, low-resolution appearance.
bits per pixel or pixel depth
The number of data bits each pixel represents. In 8-bit contexts, the pixel depth is 8, and each display pixel can be one of 256 possible colors or shades of gray. With a 24-bit raster (or with three coregistered 8-bit rasters) the pixel depth is 24, and 16,777,216 colors are possible.
BLOB
Binary large object. The data type of a column in an RDBMS table which can store large image or textual data as attributes..
BLM
Bureau of Land Management of the USDI.
block
A block is a grouping of CAD elements and attributes that can be manipulated as a whole. All CAD objects contain at least one block, the Main Block. When a block (such as the detail for a door frame) is used multiple times in a drawing, the block description is stored once, and each insertion point refers to that source.
block insertion element
A block that is inserted into another CAD block and, thus, acts as an element.
board or interface board
An electronic circuit board installed in a microcomputer to add hardware features. (See also: display board.)
border arcs
1. The arcs that create the outer edge boundary of a polygon average
2. In LIBRARIAN, the title boundary arcs that split a polygon converge into tiles.
boxcar classification or boxcar interpretation
The simplest form of automated image interpretation whereby three data ranges are selected for three coregistered images (like red, green, and blue). The three data ranges define a boxcar shape if plotted on three dimensional perpendicular axes that represent possible data values in red, green, and blue. The ranges are usually selected to represent the color variation in the three rasters for a feature of interest (like all the dark brown areas representing bare soil).
All of the data triplets in the three raster objects are tested to determine if they represent a cell inside the boxcar. All the inside cells may then be displayed or otherwise recorded as "classified."
Boxcar classification is not restricted to sets of three rasters. It may be used with any number: using 2 rasters designs a 2-dimensional "boxcar" test in a 2-dimensional space, and using "n" rasters defines an n-dimensional "boxcar" test in n-dimensional space.
box cursor or location box
Marks the focus for keyboard activity in a window.
breakline
A linear feature that defines and controls the surface behavior of a tin in terms of smoothness and continue by. Breaklines as always. x,u,z values such as streams and shorelines containing an elevation attribute are often stored as breakline features.
brightness
he physical property indicating how much electromagnetic radiation is being reflected or radiated by a chosen point. Brightness is similar to the HIS property of Intensity, and is used in the HBS color model. Brightness is also the property computed from Landsat MSS or TM images by Kauth's greenness, brightness, wetness transformations. (See also: HBS, HIS.)
bubble
A small island (often just a cell or two) of background color in the stream of a thinned, binary line in a raster. Bubbles are artifacts of the thinning process and result from binary lines that include unnoticed cells of the background color after thresholding. Bubbles must be repaired by raster editing or else the automatic vectorization process will create small, incorrect polygon elements from them.
buffer
A portion of computer memory set aside for quick temporary storage. A buffer is commonly used to store data on its way to or from a hardware device such as a disk drive. The buffer lets the computer "save up" access operations and not be slowed down by waiting on the hardware to respond at every step.
buffer zone
A border area that acts as a barrier separating or surrounding an area designated for special protection. Some states have legislated buffer zones around certain wetlands to prevent damage to the local ecosystem.
bug
An error in computer programme or in piece of electronics that causes it to malfunction.
building points
Creating and/or adding points in a vector object from imported coordinate data (like text files that contain pairs of coordinates, or database files with fields representing pairs of coordinates).
bus
The circuit channel or path a computer uses to move data and send signals between devices. A microcomputer's bus architecture determines what kinds of peripheral circuit cards can be plugged into its expansion slots. DOS and OS/2 computers have four varieties of bus architecture: PC, AT (also called ISA), EISA, and Micro Channel. The original PC bus handles 8-bit data. The AT bus doubled the data width to 16 bits and became the industry standard (thus ISA, for Industry Standard Architecture). IBM introduced the PS/2 with a proprietary bus, the 32-bit Micro Channel. Other vendors countered with a 32-bit Extended ISA (the EISA). The PC/ISA/EISA buses are backward compatible: that is, expansion cards designed for an older bus will normally work in a newer bus slot. Thus, an 8-bit display board from a PC bus works in a 16-bit ISA slot or a 32-bit EISA slot, but a 16-bit display board for an ISA bus does not work in an 8-bit PC slot.
button
A control component in a window that is activated by positioning the mouse cursor over it and pressing the left mouse button. A button may be one of several types: push button, radio, toggle, check, cascade, or option.
B/W photo, B/W image, B/W display, or B&W
A black and white photograph or some other monochrome image rendered in black, white, and shades of gray.
byte
A data element made up of 8 bits and having 256 possible values. In text-oriented processes, each byte represents one character of text. In 8-bit raster processes, each byte represents one cell value and may correspond to one pixel on the image display. (See also: bit, exabyte, gigabyte, kilobyte, megabyte, pecabyte, terabyte)
byte-oriented or 8-bit raster object
A raster in which each cell is represented by one byte (8 bits) and can therefore assume 256 possible values.