Observation Data

R2026b

The rinexread function returns observation data for RINEX v3 and RINEX v4 within the output argument data as one or more timetables. Each timetable corresponds to a set of observation epochs and may include observations from multiple satellite systems. Unlike navigation data, mixed observation data do not have a fixed field structure. The set of observation fields present in each timetable depends on the observation types declared in the RINEX file header.

FieldData TypeDescription
Time datetime Satellite clock time.
SatelliteID double Identifier of the satellite space vehicle (PRN or slot number) associated with the observation.
EpochFlag nonnegative integer

Epoch flag indicating the status of the observation epoch.

  • 0 — OK.

  • 1 — Power failure between previous epoch and current epoch.

  • 2 — Start moving antenna.

  • 3 — New site occupation (end of kinematic data; next observation at a new marker position).

  • 4 — Header information follows.

  • 5 — External event (epoch is significant).

  • 6 — Cycle slip records follow.

ReceiverClockOffset double Receiver clock offset (s)

The rest of the headers are observation codes comprised of three digits that represent type, band, and attribute. See Observation Type Descriptors for more information about the possible types, bands, and attributes.

Each descriptor code has a corresponding field for signal strength indicator (SSI) and, if the observation type is phase (L), a field for loss-of-lock indicator (LLI). For example, type L, band 1, and attribute X has the field L1X and has two additional fields, L1X_SSI and L1X_LLI.

The SSI fields are signal strength indicators specified as an integer in the range [0, 9]. A value of 0 means the strength is not known, a value of 1 indicates minimum or unreliable signal strength, 5 or above indicates a good signal-to-noise ratio, and 9 indicates the maximum.

The LLI fields are three-bit codes that are specified as an integer in the range [0, 7]. A value of 0 indicates no loss of lock or unknown. Only bit 0 relates to actual loss of lock: the least significant bit (bit 0) indicates a lost lock between the previous and current observations, the second bit (bit 1) indicates half-cycle ambiguity or slip is possible, and the most significant bit (bit 2) indicates binary offset carrier (BOC) tracking of a multiplexed BOC (MBOC) modulated signal. The LLI applies to phase (L) observations.

See Also