galmon/influxdb.md

InfluxDB schema

Influxdb knows about measurements which live in a database. Each measurement has multiple values. Such values can be tagged, and each set of tags forms a series.

Our schema is not yet very consistent, but this documentation is a start.

Measurements

These measurements are tagged by gnssid, sv and sigid. Sigid represents the band on which this data was received.

• ephemeris, updated every frame (so, a lot)
  • iod-live: current IOD number
  • eph-age: age of this ephemeris (distance from t0e)
• sisa, updated every frame
  • value: raw Galileo SISA value
• gpsura, updated every frame
  • value: raw GPS URA value
• beidouurai, updated every frame
  • value: raw BeiDou URAI value (more or less same as GPS)
• FT, GLONASS specific FT value (SISA)
• clock, clock information, updated every frame
  • offset_ns: time offset of this clock wrt GST/GPS time/Beidou time
  • t0c: t0 of the clock parameters
  • af0, af1, af2: clock polynomial parameters, in Galileo raw units, even for non-galileo SVs
• clock_jump_ns
  • value: number of nanoseconds jump in clock correction from this ephemeris to the previous one
• iono, ionospheric parameters
  • ai0, ai1, ai2: Galileo NeQuick parameters
  • sf1-sf5: The as yet unused 'storm flags'
• galbgd, Galileo Broadcast Group Delay
  • BGDE1E5a in raw galileo values
  • BGDE1E5b in raw galileo values
• galhealth, Galileo-specific health bits, values according to ICD
  • e1bhs
  • e5bhs
  • e1bdvs
  • e5bdvs
• gpshealth, GPS-specific health bits
  • value
• beidouhealth, BeiDou-specific health bits
  • sath1
• glohealth, GLONASS-specific health bits
  • Bn
• glo_taun_ns, GLONASS-specific TauN
  • value, in nanoseconds
• FT, GLONASS specific FT value
• utcoffset, for GPS, Galileo, Beidou
  • a0, in Galileo units
  • a1, in Galileo units
  • delta, in nanoseconds
  • t0t, in seconds
• gpsoffset, for Galileo, BeiDou does not fill this out. GPS doesn't need to
  • a0g, in Galileo units
  • a1g, in Galileo units
  • delta, in nanoseconds
  • t0g, in seconds
• eph-disco, statistics about ephemeris transitions
  • x,y,z: ECEF coordinates according to new ephemeris at new t0e
  • oldx,oldy,oldz: ECEF coordinates according to old ephemeris at new t0e
  • iod, oldiod: new and old IOD

RTCM SSR corrections:

These measurements are tagged by gnssid, sv

• rtcm-eph-correction:
  • iod: iod this correction corresponds to
  • radial: radial error (millimeters)
  • along: error along track
  • cross: error across track
  • dradial: velocity error in millimeters/second
  • dalong: along track velocity error
  • dcross: across track velocity error
  • ssr-iod
  • ssr-provider
  • ssr-solution
  • total-dist
  • tow
  • udi
• rtcm-clock-correction
  • dclock0: in meters
  • dclock1: meters/s
  • dclock2
  • ssr-iod
  • ssr-provider
  • tow
  • udi

Observer measurements:

• fix
  • x,y,z: ECEF coordinates of receiver
  • lat, lon: degrees latitude and longitude
  • h: hight above WGS84 ellipsoid
  • acc: accuracy (meters)
  • groundspeed: m/s
• observer_details
  • clock_offset_ns: receiver reported internal clock offset
  • clock_drift_ns: drift rate, ns/s
  • clock_acc_ns: clock accuracy (ns)
  • freq_acc_ps: picosecond/s frequency accuracy
  • uptime: uptime in seconds

Observer and SV measurements:

• rfdata
  • carrierphase
  • doppler (Hz)
  • locktime (milliseconds)
  • pseudorange (meters)
  • prstd (pseudorange standard deviation)
  • dostd (doppler standard deviation)
• correlator
  • delta_hz_corr: Doppler residual against active ephemeris, corrected for receiver clock drift
  • delta_hz: Doppler residual, uncorrected
  • elevation: Elevation of SV over horizon
  • prres: pseudorange residual according to receiver
  • qi: 0-7, quality indicator according to receiver
  • hz: Doppler Hz offset reported by receiver (uncorrected)
• recdata
  • db: receiver reported dB (can be non-sensical)
  • azi: calculated azimuth for SV from this receiver
  • ele: calculated elevation for SV from this receiver
  • prres: pseudorange residual according to receiver
  • qi: 0-7, quality indicator according to receiver
  • used: did the receiver use this SV?
• ubx_jamming
  • noise_per_ms: the Ublox noisePerMS field
  • agccnt: the Ublox automatic gain correction "count"
  • jamind: The Ublox jamming indicator
  • flag: The Ublox jamming flag field

Fed by separate tool:

SP3 design, tagged by GNSSID, SV:

• sp3_data:
  • x
  • y
  • z
  • clk
  • provider

ephemeris, tagged by GNSSID, SV, SIGID:

• active-ephemeris
  • all the raw parameters

GDOP/PDOP stats?

• covdop
  • lat
  • lon
  • cov5
  • cov10
  • cov20
  • hdop5
  • hdop10
  • hdop20

etc