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Observation Identification

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Guillaume W. Bres edited this page Dec 28, 2023 · 6 revisions

Observation Data Identification

When using Observation Data, you most likely want to know if your data is compatible with a Position solving strategy and what Position solutions (PVT) you can expect. Typically:

  • the Timescale in use: the time system in which observations are expressed
  • the time frame of the observations
  • what Constellation and Space Vehicles (SV) are in sight
  • the signal conditions (SNR, quality..)

The presence of data gaps in Observations will most likely inhibit position solving in those time frames.

We'll run the identification process on ESBC00DNK_R_20201770000_01D_30S_MO hosted in this repo.
The following applies as long as at least one Observation file is present in the pool.

Requirements

  • rinex-cli (latest)
  • git repo

Demonstration

We'll use the -i flag and -a for the complete identification.

rinex-cli \
    -f ./test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz -i -a

Results:

[2023-12-28T16:58:15Z TRACE rinex::context] loaded observations "test_resources/CRNX/V3/ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz"
[2023-12-28T16:58:15Z INFO  rinex_cli::cli] session workspace is "WORKSPACE/ESBC00DNK_R_20201770000_01D_30S_MO"
[2023-12-28T16:58:15Z INFO  rinex_cli::cli] position defined in dataset: (3582105.291, 532589.7313, 5232754.8054) [ECEF] (lat=0.96855°, lon=0.14760°

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%% Observation Data %%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
["ESBC00DNK_R_20201770000_01D_30S_MO.crx.gz"]
EpochReport {
    first: "2020-06-24T23:59:23 UTC",
    last: "2020-06-25T23:58:53 UTC",
    system: "GPST",
    sampling: {
        "dt=30s": 2879,
    },
}
Constellations: ["GPS", "GLO", "BDS", "QZSS", "GAL", "EGNOS", "BDSBAS", "SDCM"]
SV: ["G01", "R01", "J01", "E01", "G02", "R02", "J02", "E02", "G03", "R03", "J03", "E03", "G04", "R04", "E04", "G05", "R05", "C05", "E05", "G06", "R06", "C06", "G07", "R07", "C07", "E07", "G08", "R08", "C08", "E08", "G09", "R09", "C09", "E09", "G10", "R10", "C10", "G11", "R11", "C11", "E11", "G12", "R12", "C12", "E12", "G13", "R13", "C13", "E13", "G14", "R14", "C14", "G15", "R15", "E15", "G16", "R16", "C16", "G17", "R17", "G18", "R18", "G19", "R19", "C19", "E19", "G20", "R20", "C20", "G21", "R21", "C21", "E21", "G22", "C22", "R23", "C23", "ASTRA-5B", "G24", "R24", "C24", "E24", "G25", "C25", "E25", "Luch-5A", "G26", "C26", "E26", "INMARSAT-4F2", "G27", "C27", "E27", "G28", "C28", "G29", "C29", "G30", "C30", "E30", "G31", "E31", "G32", "C32", "C33", "E33", "C34", "C35", "C36", "E36", "SES-5", "C37", "G1"]
Observables: ["L1C", "L1P", "L2C", "L2I", "L2L", "L2P", "L2W", "L3Q", "L5I", "L5Q", "L6C", "L6I", "L7I", "L7Q", "L8Q", "D1C", "D1P", "D2C", "D2I", "D2L", "D2P", "D2W", "D3Q", "D5I", "D5Q", "D6C", "D6I", "D7I", "D7Q", "D8Q", "S1C", "S1P", "S1W", "S2C", "S2I", "S2L", "S2P", "S2W", "S3Q", "S5I", "S5Q", "S6C", "S6I", "S7I", "S7Q", "S8Q", "C1C", "C1P", "C1W", "C2C", "C2I", "C2L", "C2P", "C2W", "C3Q", "C5I", "C5Q", "C6C", "C6I", "C7I", "C7Q", "C8Q"]
SNR: SNRReport {
    worst: Some(
        (
            2020-06-25T00:00:00 GPST,
            "G21",
            Doppler(
                "D2W",
            ),
            DbHz12,
        ),
    ),
    best: Some(
        (
            2020-06-25T23:59:30 GPST,
            "G30",
            PseudoRange(
                "C2W",
            ),
            DbHz54,
        ),
    ),
}
No anomalies reported.

The first few lines describe that the data source is a single observation file, from a single receiver.

The RINEX file contains a geodetic marker with approximated position that we emphasize. This is useful to know, because precise positioning will be expressed as offset to this marker.

The time frame is given, we can see that the time system is GPST.
We can also see that the sampling is very steady without interruption.

Several constellations are present, including SBAS.
Phase and Dopplers are present.
The SNR is high with a peak at 54 dBHz.

No anomalies are reported, which is consistent with the steady sampling and high quality of the data.

The geodetic marker means this reference station (ESBC00DNK) has measured and estimated the receiver position. We'll use this marker as the apriori position to the position solver when demonstrating the -p opmode.

Next steps

For more indepth identification, prior advanced operations is either

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