1 | Todo's sorted by priority:
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2 |
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3 | BNS
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4 | =========================
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5 | (1) One would expect that a new ephemeris set always comes with a later validity
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6 | time tag than a previously distributed ephemeris set. However, this is not always true.
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7 | Sometimes new ephemeris sets come with a validity time tag which is earlier than the
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8 | validity time tag of a previously distributed ephemeris set. This is something
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9 | we should consider in BNS. Gerhard observed that we dont consider this right
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10 | now. The consequence is that a satellite gets lost for PPP clients because
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11 | they deal with another ephemeris set than the correctors provided by
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12 | BNS.
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13 |
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14 | BNC
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15 | =========================
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16 | (1) NMEA GGA string is not fully compatible with the standard.
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17 | The following are observations by Tamas Horvath:
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18 | 1. Time tag should refer to UTC time and not GPS system time.
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19 | 2. Time tag format is hhmmss.ss and not hhmmss.
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20 | 3. The GPS Quality indicator field is 1 (GPS SPS Mode), which is correct, as
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21 | there is no category for PPP. In my opinion the NMEA protocol should be
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22 | extended by a new indicator number for PPP to make a clear difference between
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23 | autonomous GNSS and PPP.
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24 | 4. The HDOP value is constantly 2.0, which is obviously not real. I think this
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25 | field is filled with 2.0 as a default value in BNC.
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26 | 5. The Age of Differential GPS data field is not populated. I believe here the
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27 | age of RTCM SSR data should be put.
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28 |
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29 | (2) BNC has a problem when the observation update rate is > 1Hz. Records get
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30 | mixed then in the RINEX files. A 10 Hz stream to test the situation is
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31 | available from GFZ caster 139.17.3.112:4080 through stream A17H.
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32 |
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33 | (3) GW: Keep an eye on www.igs-ip.net/PENC0.
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34 |
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