# CODA RINEX Mapping Description

CODA provides access to RINEX Observation (V3.0), Navigation (V3.0), and Clock (V2.0 and V3.0) data. Support for Meteorological data or other versions of the format is currently not available. Data access is implemented in CODA by first importing the full file and then providing access to an in-memory structure of the data via the CODA data types. Below we will describe how CODA maps the RINEX product structure to one that is based on the CODA data types. We assume you already have a decent understanding of the RINEX format and its details.

A RINEX file consists of a header section followed by a series of data records. CODA supports all mandatory header elements and most of the optional header elements for Observation, Navigation, and Clock data.

CODA will try to provide as direct a mapping to the RINEX data as possible. This means that the in memory data structure will follow to a large extend the order in which data is stored in the file. Below the mapping for the RINEX Observation, Navigation, and Clock data is provided.

## RINEX Observation data

The following table gives the mapping of header sections to CODA parameters

CODA path to variable | type class | read type | rinex header
--- | --- | --- | ---
/header/format_version | real | float | RINEX VERSION / TYPE
/header/file_type | text | char | RINEX VERSION / TYPE
/header/satellite_system | text | char | RINEX VERSION / TYPE
/header/program | text | string | PGM / RUN BY / DATE
/header/run_by | text | string | PGM / RUN BY / DATE
/header/datetime | time | double | PGM / RUN BY / DATE
/header/datetime_time_zone | text | string | PGM / RUN BY / DATE
not supported |  |  | COMMENT
/header/marker_name | text | string | MARKER NAME
/header/marker_number | text | string | MARKER NUMBER
/header/marker_type | text | string | MARKER TYPE
/header/observer | text | string | OBSERVER / AGENCY
/header/agency | text | string | OBSERVER / AGENCY
/header/receiver_number | text | string | REC # / TYPE / VERS
/header/receiver_type | text | string | REC # / TYPE / VERS
/header/receiver_version | text | string | REC # / TYPE / VERS
/header/antenna_number | text | string | ANT # / TYPE
/header/antenna_type | text | string | ANT # / TYPE
/header/approx_position_x | real | double | APPROX POSITION XYZ
/header/approx_position_y | real | double | APPROX POSITION XYZ
/header/approx_position_z | real | double | APPROX POSITION XYZ
/header/antenna_delta_h | real | double | ANTENNA: DELTA H/E/N
/header/antenna_delta_e | real | double | ANTENNA: DELTA H/E/N
/header/antenna_delta_n | real | double | ANTENNA: DELTA H/E/N
not supported |  |  | ANTENNA: DELTA X/Y/Z
not supported |  |  | ANTENNA: PHASECENTER
not supported |  |  | ANTENNA: B.SIGHT XYZ
not supported |  |  | ANTENNA: ZERODIR AZI
not supported |  |  | ANTENNA: ZERODIR XYZ
not supported |  |  | CENTER OF MASS: XYZ
/header/sys[]/code | text | char | SYS / # / OBS TYPES
/header/sys[]/num_obs_types | integer | int16 | SYS / # / OBS TYPES
/header/sys[]/descriptor[] | text | string | SYS / # / OBS TYPES
/header/signal_strength_unit | text | string | SIGNAL STRENGTH UNIT
/header/obs_interval | real | double | INTERVAL
/header/time_of_first_obs | time | double | TIME OF FIRST OBS
/header/time_of_first_obs_time_zone | text | string | TIME OF FIRST OBS
/header/time_of_last_obs | time | double | TIME OF LAST OBS
/header/time_of_last_obs_time_zone | text | string | TIME OF LAST OBS
/header/rcv_clock_offs_appl | integer | uint8 | RCV CLOCK OFFS APPL
not supported |  |  | SYS / DCBS APPLIED
not supported |  |  | SYS / PCVS APPLIED
not supported |  |  | SYS / SCALE FACTOR
/header/leap_seconds | integer | int32 | LEAP SECONDS
/header/num_satellites | integer | uint16 | # OF SATELLITES
not supported |  |  | PRN / # OF OBS

The following table gives the mapping of the epoch records structure to CODA parameters. A RINEX observation file can contain multiple epoch records. Each epoch record contains the epoch (time of observation) and observations for one or more satellites. Since per satellite system the list of observation types is fixed (as defined by the 'SYS / # / OBS TYPES' header content) the observations are grouped per satellite system. Within the epoch record you will thus, if the system is applicable to the overall file, find fields for each of the type of satellite systems (system can be 'gps', 'glonass', 'galileo', and/or 'sbas'). The field per satellite system will then contain an array of records with the observations of the satellites of that system. Each such record contains the 2-digit number of the satellite and fields (observation_type) for each of the observation types (based on the names as defined by the 'SYS / # / OBS TYPES' header content). Examples of paths that you may encounter to observations are thus e.g. /record[]/gps[]/C1C/observation and /record[]/galileo[]/L1B/observation. If the LLI and/or signal strength values are not explicitly provided in the file, they will be set to 0.

CODA path to variable | type class | read type
--- | --- | ---
/record[]/epoch | time | double
/record[]/flag | text | char
/record[]/receiver_clock_offset | real | double
/record[]/system[]/number | integer | uint8
/record[]/system[]/observation_type/observation | real | double
/record[]/system[]/observation_type/lli | integer | uint8
/record[]/system[]/observation_type/signal_strength | integer | uint8

## RINEX Navigation data

The following table gives the mapping of header sections to CODA parameters

CODA path to variable | type class | read type | rinex header
--- | --- | --- | ---
/header/format_version | real | float | RINEX VERSION / TYPE
/header/file_type | text | char | RINEX VERSION / TYPE
/header/satellite_system | text | char | RINEX VERSION / TYPE
/header/program | text | string | PGM / RUN BY / DATE
/header/run_by | text | string | PGM / RUN BY / DATE
/header/datetime | time | double | PGM / RUN BY / DATE
/header/datetime_time_zone | text | string | PGM / RUN BY / DATE
not supported |  |  | COMMENT
/header/ionospheric_corr[]/type | text | string | IONOSPHERIC CORR
/header/ionospheric_corr[]/parameter[] | real | double | IONOSPHERIC CORR
/header/time_system_corr[]/type | real | double | TIME SYSTEM CORR
/header/time_system_corr[]/a0 | real | double | TIME SYSTEM CORR
/header/time_system_corr[]/a1 | real | double | TIME SYSTEM CORR
/header/time_system_corr[]/T | integer | int32 | TIME SYSTEM CORR
/header/time_system_corr[]/W | integer | uint8 | TIME SYSTEM CORR
/header/time_system_corr[]/S | text | string | TIME SYSTEM CORR
/header/time_system_corr[]/U | real | double | TIME SYSTEM CORR
/header/leap_seconds | integer | int32 | LEAP SECONDS

The following tables give the mapping of the navigation records structure to CODA parameters. Since the record definition for a Navigation record depends on the satellite system, CODA groups all records of the same satellite type together into a single array of Navigation records. At top level these arrays can be accessed using the name of the satellite system ('gps', 'glonass', 'galileo', or 'sbas'). Below you will find the CODA record definitions for each of the different satellite types.

### RINEX Navigation record for GPS

CODA path to variable | type class | read type
--- | --- | ---
/gps[]/number | integer | uint8
/gps[]/epoch | time | double
/gps[]/sv_clock_bias | real | double
/gps[]/sv_clock_drift | real | double
/gps[]/sv_clock_drift_rate | real | double
/gps[]/iode | real | double
/gps[]/crs | real | double
/gps[]/delta_n | real | double
/gps[]/m0 | real | double
/gps[]/cuc | real | double
/gps[]/e | real | double
/gps[]/cus | real | double
/gps[]/sqrt_a | real | double
/gps[]/toe | real | double
/gps[]/cic | real | double
/gps[]/omega0 | real | double
/gps[]/cis | real | double
/gps[]/i0 | real | double
/gps[]/crc | real | double
/gps[]/omega | real | double
/gps[]/omega_dot | real | double
/gps[]/idot | real | double
/gps[]/l2_codes | real | double
/gps[]/gps_week | real | double
/gps[]/l2_p_data_flag | real | double
/gps[]/sv_accuracy | real | double
/gps[]/sv_health_gps | real | double
/gps[]/tgd | real | double
/gps[]/iodc | real | double
/gps[]/transmission_time | real | double
/gps[]/fit_interval | real | double

### RINEX Navigation record for GLONASS

CODA path to variable | type class | read type
--- | --- | ---
/glonass[]/number | integer | uint8
/glonass[]/epoch | time | double
/glonass[]/sv_clock_bias | real | double
/glonass[]/sv_rel_freq_bias | real | double
/glonass[]/msg_frame_time | real | double
/glonass[]/sat_pos_x | real | double
/glonass[]/sat_vel_x | real | double
/glonass[]/sat_acc_x | real | double
/glonass[]/sat_health | real | double
/glonass[]/sat_pos_y | real | double
/glonass[]/sat_vel_y | real | double
/glonass[]/sat_acc_y | real | double
/glonass[]/sat_frequency_number | real | double
/glonass[]/sat_pos_z | real | double
/glonass[]/sat_vel_z | real | double
/glonass[]/sat_acc_z | real | double
/glonass[]/age_of_oper_info | real | double

### RINEX Navigation record for Galileo

CODA path to variable | type class | read type
--- | --- | ---
/galileo[]/number | integer | uint8
/galileo[]/epoch | time | double
/galileo[]/sv_clock_bias | real | double
/galileo[]/sv_clock_drift | real | double
/galileo[]/sv_clock_drift_rate | real | double
/galileo[]/iodnav | real | double
/galileo[]/crs | real | double
/galileo[]/delta_n | real | double
/galileo[]/m0 | real | double
/galileo[]/cuc | real | double
/galileo[]/e | real | double
/galileo[]/cus | real | double
/galileo[]/sqrt_a | real | double
/galileo[]/toe | real | double
/galileo[]/cic | real | double
/galileo[]/omega0 | real | double
/galileo[]/cis | real | double
/galileo[]/i0 | real | double
/galileo[]/crc | real | double
/galileo[]/omega | real | double
/galileo[]/omega_dot | real | double
/galileo[]/idot | real | double
/galileo[]/data_sources | integer | uint32
/galileo[]/gal_week | real | double
/galileo[]/sisa | real | double
/galileo[]/sv_health | integer | uint32
/galileo[]/bgd_e5a_e1 | real | double
/galileo[]/bgd_e5b_e1 | real | double
/galileo[]/transmission_time | real | double

### RINEX Navigation record for SBAS

CODA path to variable | type class | read type
--- | --- | ---
/sbas[]/number | integer | uint8
/sbas[]/epoch | time | double
/sbas[]/sv_clock_bias | real | double
/sbas[]/sv_rel_freq_bias | real | double
/sbas[]/transmission_time | real | double
/sbas[]/sat_pos_x | real | double
/sbas[]/sat_vel_x | real | double
/sbas[]/sat_acc_x | real | double
/sbas[]/sat_health | real | double
/sbas[]/sat_pos_y | real | double
/sbas[]/sat_vel_y | real | double
/sbas[]/sat_acc_y | real | double
/sbas[]/sat_accuracy_code | real | double
/sbas[]/sat_pos_z | real | double
/sbas[]/sat_vel_z | real | double
/sbas[]/sat_acc_z | real | double
/sbas[]/iodn | real | double

## RINEX Clock data

The following table gives the mapping of header sections to CODA parameters

CODA path to variable | type class | read type | rinex header v2.0 | rinex header v3.0
--- | --- | --- | --- | ---
/header/format_version | real | float | RINEX VERSION / TYPE | RINEX VERSION / TYPE
/header/file_type | text | char | RINEX VERSION / TYPE | RINEX VERSION / TYPE
/header/satellite_system | text | char |  | RINEX VERSION / TYPE
/header/program | text | string | PGM / RUN BY / DATE | PGM / RUN BY / DATE
/header/run_by | text | string | PGM / RUN BY / DATE | PGM / RUN BY / DATE
/header/datetime | time | double | PGM / RUN BY / DATE | PGM / RUN BY / DATE
/header/datetime_time_zone | text | string | PGM / RUN BY / DATE | PGM / RUN BY / DATE
not supported |  |  | COMMENT | COMMENT
/header/sys[]/code | text | char |  | SYS / # / OBS TYPES
/header/sys[]/num_obs_types | integer | int16 |  | SYS / # / OBS TYPES
/header/sys[]/descriptor[] | text | string |  | SYS / # / OBS TYPES
/header/time_system_id | text | string |  | TIME SYSTEM ID
/header/leap_seconds | integer | int32 | LEAP SECONDS | LEAP SECONDS
not supported |  |  |  | SYS / DCBS APPLIED
not supported |  |  |  | SYS / PCVS APPLIED
not supported |  |  | # / TYPES OF DATA | # / TYPES OF DATA
not supported |  |  | STATION NAME / NUM | STATION NAME / NUM
not supported |  |  | STATION CLK REF | STATION CLK REF
not supported |  |  | ANALYSIS CENTER | ANALYSIS CENTER
not supported |  |  | # OF CLK REF | # OF CLK REF
not supported |  |  | ANALYSIS CLK REF | ANALYSIS CLK REF
not supported |  |  | # OF SOLN STA / TRF | # OF SOLN STA / TRF
not supported |  |  | SOLN STA NAME / NUM | SOLN STA NAME / NUM
not supported |  |  | # OF SOLN SATS | # OF SOLN SATS
not supported |  |  | PRN LIST | PRN LIST

There are a few considerations when dealing with files using the V2.0 format:

- The 'satellite_system' will have a hard-coded value of 'G' (V2.0 data is always about GPS data)
- If the 'datetime' field in the header does not follow the format as specified by V3.0 then the value for 'datetime' will be set to NaN
- The field 'time_system_id' will not be available for V2.0 data (it is an optional record field that will be set to 'no data' when you try to access it)
- The 'sys' array will always be empty (i.e. 0 element array)

The following table gives the mapping of the clock records structure to CODA parameters.

CODA path to variable | type class | read type
--- | --- | ---
/record[]/type | text | string
/record[]/name | text | string
/record[]/epoch | time | double
/record[]/bias | real | double
/record[]/bias_sigma | real | double
/record[]/rate | real | double
/record[]/rate_sigma | real | double
/record[]/acceleration | real | double
/record[]/acceleration_sigma | real | double