Retrieve Data From a CAPS Server

CAPS provides additional tools to access data and information on a CAPS.

Name

Description

capstool

A command-line tool for retrieving data and information from a CAPS server.

caps_plugin

The plugin fetches miniSEED data from a CAPS server and provides the data to seedlink

caps / capss

The RecordStream implementations for CAPS.

RecordStream for SeisComP modules

SeisComP applications access waveform data through the RecordStream interface. To fetch data from a CAPS server specific RecordStream implementations may be used:

  • caps: regular RecordStream implementation to access the CAPS server,

  • capss: RecordStream implementation to access the CAPS server secured by SSL, user name and password. Similar to https, capss will establish a Secure Socket Layer (SSL) communication.

Configuration

  1. In order to make use of the the caps RecordStream, the rsas plugin must be registered. Add the rsas plugin in the global configuration or to the modules that require the RecordStream, e.g. scautopick, scamp, scolv, scrttv:

    plugins = ${plugins},rsas
    
  2. Configure the RecordStream URL in global. Examples for caps and capss:

    recordstream = caps://server:18002
    recordstream = capss://foo:bar@server:18022
    

    Note the optional parameters.

Note

While the caps/capss RecordStream provides data in real time and from archive, some modules, e.g. fdsnws or GIS should be strictly limited to reading from archive only. Consider the option arch in these cases.

Optional Parameters

Optional RecordStream parameters which can be combined:

  • arch - read from CAPS archive only,

  • ooo - out of order, data are fetched and provided in the order of their arrival in the CAPS server, useful for analysing if data have arrived out of order,

  • pass - password if server requires authentication,

  • request-file - file specifying the streams to be requested. One stream per line. Per line: net sta loc stream startTime endTime,

  • timeout - timeout of acquisition in seconds. Data acquisition will be restarted,

  • user - user name if server requires authentication.

URL

Description

caps://server:18002?arch

Read data from CAPS archive. Stop data acquisition when all available waveforms are fetched.

caps://server:18002?ooo

Fetch data in the original order of arrival.

caps://server:18002?request-file=request.txt

Request only streams in time intervals given in request.txt

caps://server:18002?timeout=5

Apply a timeout of 5 seconds.

capss://server:18022?user=foo&pass=bar

Use secure protocol (SSL) with user name and password. Read the section on Authentication by user name and password (shadow file) for details on the generation of user names and passwords.

Combination with other RecordStream interfaces

The caps and the capss RecordStream may be combined with other RecordStream interfaces.

Examples:

  1. Decimation

    Use the decimation RecordStream interface to fetch data from a CAPS server running on localhost decimated to 1 sample per second.

    global configration:

    recordstream = dec://caps/localhost:18002?rate=1
    

    command line parameter:

    -I dec://caps/localhost:18002?rate=1
    
  2. Resample

    Use the resample RecordStream interface to fetch data from a CAPS server running on localhost resampled to 16 samples per second.

    global configration:

    recordstream = resample://caps/localhost:18002?rate=16
    

    command line parameter:

    -I resample://caps/localhost:18002?rate=16
    

Direct file access

The data files in the CAPS archive contain a small additional header describing the data format. Read the format documentation for more details. In contrast to miniSEED files in SDS archives created e.g. by slarchive or scart, the files in the CAPS archive cannot be directly read by an application.

However, you may use the command-line tool capstool for fetching data from a CAPS server based on time windows. capstool will read the data, strip the header and provide the data in their original format as a single file. capstool also provides information on available stations (-L) and streams with their time windows (-Q).

Synchronize with another CAPS server

Use caps2caps to synchronize your CAPS server with another one. You may push or pull data on either side. In contrast to the generation of regular SDS archives, e.g. by scart, the CAPS server will not generate duplicate data records if executing caps2caps multiple times. While synchronizing observe the web interface for the statistics of received, written or rejected data packages.

FDSNWS

CAPS speeks natively FDSN Web Services, FDSNWS providing waveform data via dataselect. Information on events and stations are not delivered. The waveform data will be delivered through the port configured in AS.http.port or the port configured by your Apache server, if available. Contact your system administrator for information on the Apache server. Read the documentation of the CAPS server for the configuration.

Winston waveform server (WWS)

CAPS speeks natively Winston Waveoform Server, WWS) protocol, e.g. to Swarm by USGS. Read the documentation of the CAPS server for the configuration.