sensor
The sensor table stores calibration information for specific sensor channels. This table provides a record of updates in the calibration factor or clock error of each instrument and links a sta/chan/time to a complete instrument response in the instrument table. Waveform data are converted into physical units through multiplication by the calib type located in wfdisc. The correct value of calib may not be accurately known when the wfdisc record is entered into the database. The sensor table provides the mechanism (calratio and calper) to update calib, without requiring possibly hundreds of wfdisc records to be updated. Through the foreign key inid, this table is linked to instrument, which has types pointing to flat files holding detailed calibration information in a variety of formats (see instrument).
|
FIELD |
COLUMN |
STORAGE |
EXTERNAL |
CHARACTER |
DESCRIPTION |
|
NUMBER |
TYPE |
FORMAT |
POSITION |
||
|
1 |
sta |
varchar2(8) |
a6 |
1-6 |
station code |
|
2 |
chan |
varchar2(8) |
a8 |
8-15 |
channel code |
|
3 |
time |
f1oat(53) |
f17.5 |
17-33 |
epoch time of start of recording period |
|
4 |
endtime |
f1oat(53) |
f17.5 |
35-51 |
epoch time of end of recording period |
|
5 |
inid |
number(8) |
i8 |
53-60 |
instrument identifier |
|
6 |
chanid |
number(8) |
i8 |
62-69 |
channel identifier |
|
7 |
jdate |
number(8) |
i8 |
71-78 |
julian date |
|
8 |
calratio |
f1oat(24) |
f16.6 |
80-95 |
calibration |
|
9 |
calper |
f1oat(24 ) |
f16.6 |
97-112 |
calibration period |
|
10 |
tshift |
f1oat(24) |
f16.2 |
114-129 |
correction of data processing time |
|
11 |
instant |
varchar2( 1) |
a1 |
131-131 |
discrete/continuing (y, n) snapshot |
|
12 |
Iddate |
date |
a19 |
133-151 |
load date |
|
|
|
|
|
|
|
|
Keys: |
Primary |
sta, chan, time, endtime |
|
|
|
|
|
Foreign |
inid, chanid |
|
|
|
|
Data: |
Descriptive |
sta, chan, instant |
|
|
|
|
|
Measurement |
time, endtime, jdate, calratio, calper, tshift |
|
||
|
|
Administrative |
Iddate |
|
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