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Full-Rate (MERIT-II)

Within the ILRS Operation Center (OC) the following fields of Full-Rate (MERIT-II) are checked.

ILRS Full-Rate Format (Version 3)

    1 - 7ILRS Satellite Identification Number - 7 digit number based on COSPAR ID 
     → Satellite ID must be in official list (link)ED0011
    8 - 9Year of Century - 2 digits with leading zero fill 
    10 - 12Day of Year - 3 digits with leading blank fill 
     → [ 0, ..., 366 ]ED0031
    13 - 24Time of Day - from midnight GMT with a .1 microsecond granularity and leading blank fill 
     → [ 0, ..., 864000000000 ]ED0041
    25 - 28Crustal Dynamics Project Pad ID- a 4-digit monument identification 
    29 - 30Crustal Dynamics Project 2-digit system number 
    31 - 32Crustal Dynamics Project 2-digit occupancy sequence number 
    33 - 39Azimuth
    - the geometric or true azimuth angle with a .1 millidegree granularity and leading blank fill
    40 - 45Elevation
    - the geometric or true elevation angle with a .1 millidegree granularity and leading blank fill
    46 - 57Laser Range
    - in units of two way time with a 1 picosecond granularity and leading blank fill
    58 - 64Pass RMS from the mean of raw range values minus the trend function, for accepted ranges (two-way value in picoseconds). 
    65 - 68Wavelength of the laser with leading blank fill
    The user of the data should interpret the value given as follows:
    3000 - 9999: units are 0.1 nanometer
    1000 - 2999: units are 1.0 nanometer
    For the station generating the data, the rule is:
    Wavelength in rate 0.3000 - 0.9999 microns: unit 0.1 nanometer
    Wavelength in rate 1.000 - 2.999 microns: unit 1.0 nanometer
    69 - 73Surface Pressure
    - .1 millibar granularity with leading blank fill
    74 - 77Surface Temperature
    - .1 degree Kelvin granularity with leading blank fill
    78 - 80Relative Humidity at Surface
    - percentage with leading blank fill
    81 - 85Tropospheric refraction correction
    - a round trip refraction correction with a 1 picosecond granularity and leading blank fill
    86 - 91Center of Mass Correction
    - a round trip correction with a 1 picosecond granularity and leading blank fill
    92 - 96Receive Amplitude
    - a positive linear scale value with leading blank fill
    97 - 104Applied System Delay
    - the two way system delay applied in the current record with a 1 picosecond granularity and leading blank fill
    105 - 110Calibration Delay Shift
    - a measure of two way calibration stability with a 1 picosecond granularity and leading blank fill.
    111 - 114Root Mean Square (RMS) of raw system delay values from the mean. Two-way value in picoseconds. If pre- and post- pass calibrations are made, use the mean of the two RMS values, or the RMS of the combined data set. 
    115Normal Point Window Indicator
    - indicates whether or not the record represents a normal point and the time span of the normal point
    0: not a normal point
    1: 5-second normal point (GFZ-1)
    2: LLR normal point
    3: 15-second normal point (TOPEX)
    4: 20-second normal point
    5: 30-second normal point
    6: 1-minute normal point
    7: 2-minute normal point (LAGEOS)
    8: 3-minute normal point
    9: 5-minute normal point (ETALON)
    116 - 119Number of raw ranges compressed into normal point leading blank fill  
    120Epoch Event - indicates the time event reference.
    Currently, only 1 and 2 are used for laser ranging data.
    0 = Ground receive time
    1 = Satellite transmit time (standard for LAGEOS)
    2 = Ground transmit time
    3 = Satellite receive time
    121Epoch Time Scale - indicates the time scale reference.
    Other flags may appear for historical data.
    3 = UTC (USNO)
    4 = UTC (GPS)
    7 = UTC (BIH)
    122Angle Origin Indicator - source of angle values.
    0 = Unknown (converted from MERIT I)
    1 = Computed (from range)
    2 = Command (predicts and operator inputs)
    3 = Measured (calibrated instrument readings)
    123Tropospheric Refraction Correction Indicator
    0 = Data has been corrected using the Marini-Murray formula
    1 = Data has not been corrected
    124Center of Mass Correction Application Indicator
    0 = Applied
    1 = Not applied
    125Receive Amplitude Correction Indicator
    0 = Data has been receive amplitude corrected
    1 = Data has not been receive amplitude corrected
    126System calibration method and delay shift indicator.
    Indicates the type of calibration and the type of calibration shift given in columns 105-110
    127System CHange indicator (SCH).
    A flag to increment for every major change to the system (hardware or software). After the value '9' return to '0', and then continue incrementing. The station and data centers should keep a log in a standard format of the value used, the date of the change, and a description of the change.
    128System Configuration Indicator (SCI).
    A flag used to indicate alternative modes of operation for a system (e.g., choice of alternative timers or detectors, or use of a different mode of operation for high satellites). Each value of the flag indicates a particular configuration, which is described in a log file held at the station and at the data centers. If only a single configuration is used then use a fixed value. If a new configuration is introduced then use the next higher flag value. If value exceeds '9' then return to '0', overwriting a previous configuration flag (it is not likely that a station will have 10 current possible configurations).
    129Format Revision Number Indicator - indicates the version of the MERIT II format for the current record.
    Data prior to MERIT II that is converted into the MERIT II format will have a revision number of '0'.
    130Release Flag Indicator - indicates when this record first appeared on a release tape. Cooperating stations which send release tapes to the CDDIS will use a numbering scheme beginning with '1'. Release tapes from the CDDIS will have a labelling scheme beginning with 'A'. Non-operational engineering data will have a release flag of 'Z'. Data released prior to the MERIT II implementation will have a release flag of '0'.  

    Additional Checks

     → The SOD must be in the official list (link)ED0051

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