Backup
A copy of a file, directory, or volume on a separate storage device from the original, for the purpose of retrieval in case the original is accidentally erased, damaged, or destroyed. Backlight
An LCD screen that has its own light source from the back of the screen, making the background brighter and characters appear sharper. Bandwidth
That range of frequencies that compose a signal. Expressed in Hertz. Base Station
Also called a Reference Station. A ground station at a known location used to derive differential corrections to GPS signals. The reference station receiver tracks all satellites in view, computes their pseudoranges, corrects these for errors, and then transmits the corrections to users. In the case of Differential GPS (DGPS) the base station calculates the error for each satellite and, through differential correction, improves the accuracy of GPS positions. Battery
A battery is an electrochemical cell or enclosed and protected material that can be charged electrically and provide a static potential for power or released electrical charge when needed. Beacon
Stationary transmitter that emits signals in all directions (also called a non-directional beacon). In DGPS, the beacon transmitter also broadcasts pseudorange correction data to nearby GPS receivers for greater accuracy. Beaming
Term coined by Palm to describe the way to transmit data from one PDA to another via infrared ports. Bearing
See azimuth. In a GPS receiver, bearing usually refers to the direction to a waypoint. Bench mark
A material object, natural or man-made, with a known elevation or horizontal location. Bench marks can be used as reference points when travelling a route or in determining the elevation of nearby land features. Bias
All GPS measurements are affected by biases and errors, such as atmospheric conditions. Their combined magnitudes will affect the accuracy of the positioning results (they will bias the position or baseline solution). Biases may be defined as being errors that cause the true measurements to be different from observed measurements by a constant, predictable or systematic amount. Bit
A unit of information in an electronic system expressed as a choice between two possible values, for example, 0 or 1. Bitmap image
An image with 1 bit of colour information per pixel, also known as a bitmapped image. Bluetooth
A short range, wireless networking technology allowing personal devices such as a PDA, GPS unit, computer, printer or mobile phone to exchange and synchronise data. It works on short range as long as the devices are up to approximately 10metres apart. Brightness
A measure of the overall intensity of the image. The lower the brightness value, the darker the image; the higher the value, the lighter the image will be. Bluetooth GPS (BTGPS)
When a device, such as a PDA is linked to a GPS receiver via Bluetooth. |
