Here is some additional information on the channel designations at
a broadgand station using SEED name conventions:
(SEED = Standard for the Exchange of Earthquake Data ).
Note that the SEED names are different from the former channel
streem descriptor names: ie VBB-Z is BHZ, LP-Z is LHZ, VLP-? is VH?,
VSP-? is SH?, etc. The names do not exactly specify the sample rate,
but the conventions of the IRIS stations are preferred.
here is the file vbb_system_description from CCM:
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File USR/GSN/DP_LOGS/ VBB_SYSTEM_DESCRIPTION at station CCM:
(This is the response to the "r" command in any data retrieval mode.)
Station : CCM Cathedral Cave, Missouri
Lat: 38.0557 N Lon:-91.2446 W Elev:222.5m
(51 meters below the local surface)
Components: Z : + = ground motion up
N : + = ground motion north
E : + = ground motion east
Digitizer: Quanterra Q980 split system (9 24-bit channels).
SEED NAMES: BHZ,BHN,BHE:
Streams: VBB : 20 SPS: on 24-bit channels, from Streckeisen STS-1
seismometers. Instrument response is flat
to velocity from 10 Hz to 360 sec; Sensitivities are
Z = 2278 Vsec/m; N = 2142 Vsec/m; E = 2058 Vsec/m.
Recorded continuously on line and on tape.
LHZ,LHN,LHE:
LP : 1 SPS: derived by constant-time-delay Finite Impulse
Response (FIR) digital filter from VBB stream in real
time, cutoff at 2.7 S period. 4x Gain. Recorded continuously.
VHZ,VHN,VHE:
VLP : 0.1 SPS: derived by FIR filter from LP stream in real
time, cutoff at 27 S period. 4x Gain. Recorded continuously.
UHZ,UHN,UHE:
ULP : 0.01 SPS: derived by FIR filter from VLP stream in real
time, cutoff at 270 S period. Recorded continuously.
Micro-Barometer Data, as of 24 Feb. 1995:
U data is direct barometer at 419.43 counts/Pascal;
V data is 3600 sec high pass of U;
W data is 100 sec high pass of U.
BHU,BHV,BHW:
U,V,W VBB: 20 SPS: on 24-bit channels, same response as STS-1s
LHU,LHV,LHW; VHU,VHV,VHW; UHU,UHV,UHW:
LP, VLP, and ULP barometric data also recorded continuously.
Very high gain, short period channels for the CTBT (Comprehensive Test
Ban Treaty) from a separate set of 1 hz seismometers:
SHZ,SHN,SHE:
VSP : 40 SPS: on 24-bit channels, from GS-13 seismometers.
Recording continuously but NOT event detected.
(The amplifiers for the GS-13's are flat to 25 hz.)
EHZ,EHN,EHE:
ESP : 80 SPS: on 24-bit channels, from GS-13 seismometers.
Event recorded only. (online buffers; not on tape)
Various SOH channels are also recorded, including STS-1 mass position
(VMZ,VMN,VME), DA supply voltage (VE1,UE1), average free packets
(AFP), clock drift and corrections (ACD, AFC), and DA instrument
temperature (VKI).
Note: FIR filter delays are accounted for in the header reported
with the data.
Response: Basic response for the LP, VLP, and ULP channels is flat to
ground velocity from the FIR filter upper cutoff to the
second-order lower corner at 360 S period.
_________________________________________
Regards,
Sean-Thomas
__________________________________________________________
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Larry Cochrane <cochrane@..............>