# StongmotionII Format

(last revised April 16, 2002)

    Each TYPE_STRONGMOTIONII message is intended to contain information for one
    channel only, with optional event association information.

    Field units with multiple channels will produce multiple TYPE_STRONGMOTIONII
    messages.

    All measurements in the Earthworm TYPE_STRONGMOTIONII message are assumed to be
    positive. Any other negative value will result in unpredictable behavior from
    strong motion applications. If you have sources that may produce signed values
    for PGA, PGV, PGD, or RSA values, you must be sure to change these to absolute
    values before they are put into this message.

    Message format: everything in quotes is present verbatim in the message. Other
    fields are described below. Unless otherwise shown, fields are separated by
    spaces. Lines are separated by ASCII newline characters.

    "SNCL:" sta.comp.net.loc
    "TIME:" date-time
    "ALT:" alternate date-time "CODE:" altcode
    "PGA:" pga "TPGA:" tpga
    "PGV:" pgv "TPGV:" tpgv
    "PGD:" pgd "TPGD:" tpdg
    "RSA:" nrsa"/"pdrsa rsa"/"pdrsa rsa...
    "QID:" qid qauthor

    All lines and fields must be present. Null values are described for applicable
    fields.

    sta.comp.net.loc: Station, component, network, and location codes with `.'
    between adjacent fields. Fields may be any length between 1 and (6, 8, 8, 2)
    characters in length, respectively. Use `-' if no value is used for the
    location code.

    date-time: time in the format yyyy/mm/dd hh:mm:ss.sss (year, month, day, hour,
    minute, seconds to thousandths. This time is the main timestamp for the
    message. If the message came from an SM box in the field, then this is the
    trigger time reported by the box. If the message came from a module processing
    continuous telemetry, then this is the pick time or earliest of PGA, PGV, or
    PGD time. If no value is available for this or any other time, fill the field
    with the null date-time "0000/00/00 00:00:00.000".

    alternate date-time: same format as above. This is the optional alternate
    timestamp for the message. This field is provided as a sanity check or
    correction of the main timestamp(t). This timestamp could be assigned by an
    acquisition module, database loader, human, or other. The author type of this
    timestamp is determined by altcode (see below).

    altcode: Required if alternate date-time is specified. Code specifying the
    source of the alternate date-time field. Possible values:
     Value:         Description:
       0           Code for no alternate time.
       1           Code for an alternate time derived by a program module that
                      receives a message from a box in the field.
       2           Code for an alternate time derived by the database or strong
                      motion database insertion module.
       3           Code for an alternate time derived by a Human (who has
                      hopefully reviewed the data).

    pga: The Peak Ground Acceleration(PGA) for this message. (cm/s/s)
    tpga: Time of the pga, yyyy/mm/dd hh:mm:ss.sss
    pgv: The Peak Ground Velocity(PGV) for this message. (cm/s)
    tpgv: Time of the pgv, yyyy/mm/dd hh:mm:ss.sss
    pgd: The Peak Ground Displacement(PGD) for this message. (cm)
    tpgd: Time of the pgd, yyyy/mm/dd hh:mm:ss.sss

    Any values not available for pga, pgv, and pgd should be assigned -1.0, the
    null value.

    nrsa: Number of response spectral acceleration (RSA) pairs. Valid value range
          is 0 - 20
    pdrsa rsa: space-separated pair where pdrsa is the period at which RSA values
               are given; rsa is the response spectral acceleration (cm/s/s). Each
          pair of values is preceed by the "/" character. All the values must
          appear on one line.