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Introduction || Dial-up Operation || Real-Time Operation || ShakeMap || Station Maps
The NSMP Near-real-time Acquisition System was installed on the USGS Menlo Park, California campus in April of 1999 and is maintained by National Strong-Motion Data Center (NSMDC) staff. The acquisition system was in a test mode until August of 1999. On August 27, 1999, the system began automatically receiving data from NSMP digital recorders with dial-up capability in the San Francisco Bay region. The heart of the NSMP acquisition system is the Kinemetrics Network Management System (NMS) acquisition software.
NMS runs on Windows95/98/Me/NT/XP systems. The Network Management System is a multithreaded application (i.e. it is capable of doing more than one thing at a time). It has an easy to use Windows interface, a 60-page manual, and integral on-line help using the Windows Context Sensitive help features.
The NMS can support Kinemetrics Altus series recorders in several modes, including direct connect, remote dial-up, or streaming data modes. The direct connect and remote dial-up modes are used for the reporting of recorder-determined events. Uploaded event files may be stored in a number of ways, including in subdirectories by station name and recorder serial number, in subdirectories by date, or in a flat file structure (i.e. no subdirectories)
Altus Streaming data mode is used to monitor continuously transmitted digital data streams (maximum of six channels per recorder) using the Kinemetrics Serial Data Streams (SDS) transmission protocol. Data transmitted in this manner can be displayed, recorded and stored locally at the PC based upon a number of user selectable parameters, which include digital trigger filters, triggers, and storage methods. Streaming data mode is also supported for selected models of the Leica differential GPS receiver, allowing displacement data from these units to be recorded and stored along with the data from Altus recorders.
NMS supports multiple protocols: all Kinemetrics Altus products; the QDR (SMA-1 digital retrofit); and the Leica differential GPS unit (MC1000). Kinemetrics also supports the Quanterra protocol (Kinemetrics acquired Quanterra in July, 1999).
The NSMP Menlo Park Near-real-time Acquisition System has the following major features:
Four hundred and six NSMP digital recorders are currently hooked up to telephone lines (110 in Southern California, 75 in Northern California, 37 in Washington, 30 in Alaska, 27 in Hawaii, 16 in Utah, 12 in Nevada, etc). Dial-up stations have “DU” or "DI" (dial-in only) in the telemetry column of online station lists. (Dial-up Station Maps).
The Altus digital field recorders are set to dial in when an event occurs. An “event” can be defined as a seismic triggered recording, an alarm level exceedance (that can be different from the trigger level), loss of AC power at the recorder or recorder reaches a predefined temperature level, or a functional test of the recorder.
The recorder can also place a call at predetermined times of day (from once per day up to once every 15 days). This “check-in” can either be used as validation that the system is able to originate, transmit, and process calls, and/or delay fetching of the time series until the time designated.
Once a call has arrived on the Menlo Park campus, it is routed through one of two NSMP 30-extension capacity telephone switches (circuit boards). The switches send the call to one of 48 available NSMP open analog lines. Each of the dedicated 48 lines from the switching system has its own unique telephone number. The lines are connected to two 24-jack telephone panels in the back of a NSMP computer rack, which in turn are connected to 48 analog modems housed in two modem nests. Both modem nests can hold up to 16 dual-modem cards (32 modems total per nest). Each modem is connected to an RS-232 port.
There are three NT-workstation computers running NMS software. Each PC is equipped with a internal multiple communication port board and external serial expander box that provides 16 com ports (PCs only come with 2-4 com ports). The NMS software monitors the RS-232 ports waiting for Carrier Detect (that the modem has answered). Upon connection, the NMS will accept the recorder identification and the reason for the call (seismic event, loss of AC, etc.). Once the reason has been accepted, the status of the recorder will be queried and saved, indicating the battery voltage, memory capacity, temperature, and other factors.
After getting status, the A: and B: drives of the recorder are scanned, and any new files are processed. Processing can include (based upon the options selected):
Lastly, a check is made for aftershocks to make sure that no new events have occurred during file transfer. If so, they are also processed, and when no further activity remains, the connection is terminated, freeing the line. Once a file has been downloaded from the field recorder, the file’s tag is changed to indicate that the file has been acquired. NMS can acquire files regardless of the file tag if the files do not already exist in the target directory.
The NMS allows also users to manually communicate with field recorders using Monitor Mode. Whether using event based reporting or streaming data connections, Monitor mode can be used to “listen in” on communications, providing a useful diagnostic tool. Monitor mode allows one of the following choices:
The three NMS computers are connected to a NSMP NT fileserver computer via a fast 10/100-Mbit ethernet switch. Data and status files collected by NMS are stored on the NT fileserver that is connected to the Western Earthquake Hazards Team’s public local area network (LAN). The heartbeat file generated by each computer running NMS is currently stored on the NT fileserver and is monitored by software that sends pages to NSMPDC staff when a heartbeat has not been received in a specified time interval.
Each acquisition PC running NMS supports up to 96 channels for streaming data (16 data ports, with each port capable of supporting up to 6 channels per recorder). The streaming data can be displayed using the NMS Waveform graphics display.
One hundred and six NSMP digital recorders transmit real-time, continuous data (63 in the San Francisco Bay region to the Northern California Seismic Network in Menlo Park, CA, 17 in Southern California to the Southern California Seismic Network in Pasadena, CA, 13 in Utah, etc.). Real-time stations have “RT” in the telemetry column of online station lists. (Real-time Station Maps).
Copies of the data files are automatically transferred to a USGS Northern California Seismic Network (NCSN) computer system that decodes the binary event files, calculates peak ground acceleration and velocity values, and exports the peaks data to clients across the United States for generation of local ShakeMaps.
This page was last modified on 08/01/2007.
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