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发表于 2007-9-7 12:30:59
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0 thru 9
1 PPS (1 Pulse Per Second)
Generally a GPS receiver gives out a precise 1 PPS pulse (1 pulse per second) to mark exact
second intervals (1 s). This signal is used for precise timing and synchronization. The GPS
receiver produces a 1PPS pulse with a defined level (e.g. TTL level) and a defined pulse length.
2D (Two Dimensional)
The horizontal position with latitude/longitude (or northing/easting or X/Y) is called 2D
coordinate.
2D Coverage
The number of hours-per-day with three or more satellites visible. Three visible satellites can be
used to determine location (longitude and latitude) if the GPS receiver is designed to accept an
external altitude input (Altitude Hold).
2D Mode
A 2D (two dimensional) position fix that includes only horizontal coordinates. It requires a
minimum of three visible satellites.).
2D Navigation
Navigation Mode in which a fixed value of altitude is used for one or more position calculations
while horizontal (2-D) position can vary freely based on satellite range measurements. It requires
a minimum of three visible satellites.
2drms (Two Distance RMS Error)
A position accuracy measure defined as twice the RMS of the horizontal error. This
approximately corresponds to the 95% confidence interval, or "two sigma standard deviation"
value.
3D (Three Dimensional)
The horizontal and vertical position with latitude/longitude/altitude (northing/easting/altitude or
X/Y/Z) is called 3D coordinate.
3D Coverage
The number of hours-per-day with four or more satellites visible. At least four visible satellites
are required to determine longitude, latitude and altitude, with the receiver clock error as a
fourth parameter to be determined.
3D Mode
A 3D (three dimensional) position fix that includes horizontal coordinates plus altitude. It
requires a minimum of four visible satellites.
3D Navigation
Navigation mode in which altitude and horizontal position (longitude and latitude) are
determined from satellite range measurements.
50BPS (50 Bit Per Second)
The usable data stream transmitted by a GPS-Satellite.
The GPS Dictionary - Reference Document µ-blox ag
GPS-X-00001 \\Whale\data\documents\Gps\X\Original\GPS-X-00001.doc Page 3
A thru B
A/D (Analog to Digital)
The conversion from analog to digital. The conversion is done by a converter (ADC: Analog-
Digital-Converter).
Absolute Positioning
Positioning mode in which a position is identified with respect to a well-defined coordinate
system, commonly a geocentric system (i.e., a system whose point of origin coincides with the
center of mass of the earth).
Accuracy
The degree of conformance between the estimated or measured position, time, and/or velocity
of a GPS receiver and its true time, position, and/or velocity as compared with a constant
standard. Radio navigation system accuracy is usually presented as a statistical measure of
system error and is characterized as follows:
Predictable - The accuracy of a radio navigation system's position solution with respect to the
charted solution. Both the position solution and the chart must be based upon the same
geodetic datum.
Repeatable - The accuracy by which a user can return to a position, whose coordinates have
been measured previously with the same navigation system.
Relative - The accuracy with which a user can measure position relative to that of another user
of the same navigation system at the same time.
Acquisition Time
The time it takes a GPS Receiver to acquire a lock onto enough satellites for a position fix (three
satellites for a 2D and four satellites for a 3D solution).
Active Antenna
A GPS-Antenna with an integrated low noise amplifier (LNA)
ALI à see Automatic Location Identification
Almanac
Data transmitted by a GPS...........[em05] |
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