Holux GM-83 - Manual (Page 4)

GM-83 User’s manual
4
1.3.4 Performance
1) Tracks up to 12 satellites.
2) Update rate: 1 second.
3) Acquisition time:
Reacquisition 0.1 sec, averaged
Hot start 8 sec. averaged
Warm start 38 sec. averaged
Cold start 45 sec. averaged
4) Position accuracy:
Non DGPS (Differential GPS)
Position 5~25 meter CEP
Velocity 0.1 meters/second.
Time 1 microsecond synchronized GPS time
DGPS (Differential GPS)
Position 1 to 5 meters, typical
Velocity 0.05 meters/second, typical
EGNOS/WAAS
Position < 2.2 meters, horizontal 95% of time
< 5 meters, vertical 95% of time
5) Dynamic Conditions:
Altitude 18,000 meters(60,000 feet) max
Velocity 515 meters/second (1000 knots) max
Acceleration 4 G, max
Jerk 20 meters/second³, max
1.3.5 Interfaces
1) Dual communication channel TTL or RS232 levels, with user selectable baud rate (4800-Default,
9600, 19200, 38400).
2) NMEA 0183 Version 2.2 ASCII output (GGA, GLL, GSV, GSA, RMC, VTG).
3) Real-time
Differential Correction input (RTCM SC-104 message types 1, 2 and 9).
2. Operational characteristics
2.1 Initialization
As soon as the initial self-test is complete, the GM-83 begins the process of satellite acquisition and
tracking automatically. Under normal circumstances, it takes approximately 45 seconds to achieve a position
fix, 38 seconds if ephemeris data is known. After a position fix has been calculated, information about valid
position, velocity and time is transmitted over the output channel.
The GM-83 utilizes initial data, such as last stored position, date, time and satellite orbital data, to
achieve maximum acquisition performance. If significant inaccuracy exists in the initial data, or the orbital
data is obsolete, it may take more time to achieve a navigation solution. The GM-83 Auto-locate feature is
capable of automatically determining a navigation solution without intervention from the host system.
However, acquisition performance can be improved as the host system initializes the GM-83 in the following
situation:
z Moving further than 500 kilometers.
z Failure of Data storage due to the inactive internal memory battery.