Chapter 4 PQ3198 GPS Positioning and Time Correction
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The PQ3198 performs time correction when the PW9005 has acquired GPS satellites and
calculated its position.
Two types of time correction are used, depending on the PQ3198’s operational status: con-
tinuous time correction and millisecond time correction.
When the GPS status changes after recording has been started with the PQ3198 in the
time-corrected state (with a blue GPS mark), the next GPS event is generated.
1.
GPS error (GPS IN)
Indicates that a GPS error has occurred.
(The instrument changed from the time-corrected state [blue GPS mark] to the error
state [GPS mark other than blue].)
2.
GPS position detected (GPS OUT)
Indicates that the GPS error was cleared.
(The instrument changed from the error state [GPS mark other than blue] to the time-
corrected state [blue GPS mark].)
3.
GPS time error (GPS Err)
Indicates that GPS time correction is not possible.
(The difference between the PQ3198’s internal clock and the GPS time reached or
exceeded 16 ms.)
4.2 Time Correction Processing
Continuous time cor-
rection
Continuous time correction is performed while the PQ3198 is in
[SETTING]
mode. The PQ3198’s time data is corrected with time
data acquired from GPS satellites once every second. As long as the
GPS mark is blue, the PQ3198 is synchronized with GPS time.
Millisecond time cor-
rection
Millisecond time correction is performed whenever the PQ3198 is not in
[SETTING]
mode. As long as the difference between the PQ3198’s
internal clock and the GPS time is less than 16 ms, time correction is per-
formed once every 30 seconds using millisecond units.
The precision of the PQ3198’s internal clock is 0.3 s/day (at 23°C ±5°C). If
the PW9005 is unable to detect its position for a certain period of time
(about 1 hour), the difference between the PQ3198’s internal clock and
GPS time may exceed 16 ms.
A GPS event is generated and time correction is halted during subsequent
recording if the difference between the PQ3198’s internal clock and GPS
time exceeds 16 ms while the PQ3198 is recording, since such a large dif-
ference would compromise the measurement data’s time consistency.
(Once recording is stopped and the PQ3198 returns to
[SETTING]
mode,
continuous time correction is used.)
4.3 GPS Event Function
HIOKI PW9005A980-06
Summary of Contents for PW9005
Page 2: ...HIOKI PW9005A980 06 ...
Page 10: ...第 1 章 概要 6 HIOKI PW9005A980 06 ...
Page 14: ...第 2 章 PQ3198 と接続する 10 HIOKI PW9005A980 06 ...
Page 22: ...第 4 章 PQ3198 の GPS 測位と 時刻補正について 18 HIOKI PW9005A980 06 ...
Page 24: ...第 5 章 仕様 20 HIOKI PW9005A980 06 ...
Page 28: ...第 6 章 保守 点検 24 HIOKI PW9005A980 06 ...
Page 29: ...HIOKI PW9005A980 06 ...
Page 30: ...HIOKI PW9005A980 06 ...
Page 31: ...PW9005 GPS BOX Instruction Manual HIOKI PW9005A980 06 ...
Page 32: ...HIOKI PW9005A980 06 ...
Page 40: ...Chapter 1 Overview 6 HIOKI PW9005A980 06 ...
Page 54: ...Chapter 5 Specifications 20 HIOKI PW9005A980 06 ...
Page 58: ...Chapter 6 Maintenance and Service 24 HIOKI PW9005A980 06 ...
Page 59: ...HIOKI PW9005A980 06 ...
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