SINEX Format for GNSS Biases (Bias-SINEX) Version 1.00
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- This update is based on preliminary version 0.01 (developed by Tim Springer).

- Format version number is 1.00.

- Bias-SINEX 0.01 files should be compatible with format version 1.00.

- Recommended file extension is ".bia" (or ".BIA").

- Essential updates/changes with respect to the previous version (0.01) are:
  - Revised list of bias types (see below).
  - "OBS1"-only entries (with blank "OBS2" field) are allowed in order to
    support observable-specific (or pseudo-absolute) bias values/corrections.
  - "BIAS_START__"-only entries are allowed, in particular for applications
    with high bias update rates.
    - "BIAS_START__" to "BIAS_END____": Time window of applicability of a given
      bias value, or estimate.
    - "BIAS_START__"-only (with empty "BIAS_END____"): Time stamp for bias
      value. Piece-wise linear interpolation is assumed for times in between.
    REMARK: Either time windows or time stamps (epochs) must be used (in a
            file).
  - Two (optional) extra fields were added (in order to give biases specific to
    receiver types and firmware, like, e.g., DCPB values relevant to GLONASS
    ambiguity resolution):
    - RECEIVER_TYPE_______
    - RECEIVER_FIRMWARE___
  - Format version 1.00 will support code as well as phase biases.

- Old declaration of bias types (version 0.01):
  - DCB: Differential Code Bias (commonly used for C1P-C2P, C1P-C1C, C2P-C2C
         computed in ionosphere analysis or direct estimation)
  - IFB: Inter-Frequency Bias (commonly used for LC GLONASS code biases
         computed in clock analysis)
  - ISB: Inter-System Bias (commonly used for LC intersystem receiver code
         biases computed in clock analysis)
- New declaration of bias types (version 1.00):
  - "   " (or DCB/DPB): Differential Code or Phase Bias
  - LCB: LC-specific Bias (computed in clock analysis)
  IMPORTANT NOTE: IFB and ISB are interpreted as LCB. IFB and ISB are no longer
                  allowed in version 1.00 files. Instead LCB has to be be used.
  Possibly (see below):
  - WLB: WideLane Bias
  - NLB: NarrowLane Bias
  ADDITIONAL NOTES:
  - General rule: The bias type (code or phase) is defined by OBS1 (and OBS2).
  - Absolute, or differential biases:
    "   " (or DCB/DPB): If OBS1-only (no OBS2): Bias with respect to OBS1
                        If OBS1 and OBS2: Bias difference for OBS1-OBS2
  - Biases for particular linear combinations:
    LCB:                Ionosphere-free LC of OBS1 and OBS2
    WLB:                Widelane-LC        of OBS1 and OBS2
    NLB:                Narrowlane-LC      of OBS1 and OBS2

- Added descriptive records:
  Already used:
    SAMPLING INTERVAL                              300
  Possibly introduced:
    BIAS INTERVAL                                86400
    DETERMINATION METHOD
    DATUM DEFINITION

- Supported GNSS:
  - G: GPS
  - R: GLONASS
  - S: SBAS payload
  - E: Galileo
  - C: Compass/BeiDou
  - J: QZSS

- Declared sign convention:
    bias = estimator - (true or unbiased) parameter
    bias = observation - true or unbiased observation
    observation = true observation + bias
    true observation = observation - bias
    Numerical example: ground truth 11, observed 7, bias (or error) -4

- Open question: whether WLB and NLB (in cyc?) should be supported in 1.00.

- This summary file may be found at:
  ftp://ftp.unibe.ch/aiub/bcwg/format/

- The updated format description (draft version 1.00) should become available
  soon.

- Example (more examples should follow with the updated format description):

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*-------------------------------------------------------------------------------
+BIAS/SOLUTION
*BIAS SVN_ PRN SITE DOMES____ OBS1 OBS2 BIAS_START__ BIAS_END____ UNIT __ESTIMATED_VALUE____ _STD_DEV___ RECEIVER_TYPE_______ RECEIVER_FIRMWARE___
 LCB  E016 E16 GIEN 12724M003 C1C  C7Q  11:113:86385 11:115:00285 ns   -.157174143960592E+03 .259286E+02
 LCB  E016 E16 GKIR 10403M003 C1C  C7Q  11:113:86385 11:115:00285 ns   -.153942459345551E+03 .259286E+02
 LCB  E016 E16 GKOU 97301M211 C1C  C7Q  11:113:86385 11:115:00285 ns   -.163243805130824E+03 .259285E+02
 LCB  E016 E16 GLPG 41510M002 C1C  C7Q  11:113:86385 11:115:00285 ns   -.151698143836368E+03 .259290E+02
 LCB  E016 E16 GMAL 33201M002 C1C  C7Q  11:113:86385 11:115:00285 ns   -.156472089904428E+03 .259285E+02
 LCB  E016 E16 GMIZ 21702M003 C1C  C7Q  11:113:86385 11:115:00285 ns   -.167156432084244E+03 .259321E+02
 LCB  E016 E16 GNNO 50181M002 C1C  C7Q  11:113:86385 11:115:00285 ns   -.156922861008147E+03 .259665E+02
 LCB  E016 E16 GNOR 13535M001 C1C  C7Q  11:113:86385 11:115:00285 ns   -.153679440866705E+03 .259285E+02
 LCB  E016 E16 GOUS 50212M004 C1C  C7Q  11:113:86385 11:115:00285 ns   -.101593337222667E+03 .259439E+02
 LCB  E016 E16 GTHT 92201M014 C1C  C7Q  11:113:86385 11:115:00285 ns   -.159918985571303E+03 .259356E+02
 LCB  E016 E16 GUSN 40451M126 C1C  C7Q  11:113:86385 11:115:00285 ns   -.149146613879327E+03 .259279E+02
 LCB  E016 E16 GVES 66037M002 C1C  C7Q  11:113:86385 11:115:00285 ns   -.156221372596643E+03 .259288E+02
-BIAS/SOLUTION
*-------------------------------------------------------------------------------

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