pd0_parser

Low-level binary parser for RDI ADCP files in PD0 format. Returns raw data as NumPy arrays.

Note

Most users should use binary_reader instead, which wraps this module and returns convenient xarray.Dataset objects. Use pd0_parser only if you need direct binary access or are building a custom reader.

Functions

Function	Description
`fileheader()`	Parse file structure — ensemble locations and data type offsets
`fixedleader()`	Read static instrument configuration (36 fields × n ensembles)
`variableleader()`	Read per-ensemble sensor data (48 fields × n ensembles)
`datatype()`	Read 3D profile data — velocity, correlation, echo, percent good, status

Usage

Call fileheader() once and pass its output to all other functions — this avoids re-scanning the file for each data type.

from pyadps.io import pd0_parser

# Parse file structure once
dt, byte, byteskip, offset, idarray, n_ens, err = pd0_parser.fileheader('deployment.000')

# Reuse for all subsequent reads
fl, _, _          = pd0_parser.fixedleader('deployment.000', byteskip, offset, idarray, n_ens)
vl, _, _          = pd0_parser.variableleader('deployment.000', byteskip, offset, idarray, n_ens)
vel, _, _, _, _   = pd0_parser.datatype('deployment.000', 'velocity',
                        byteskip=byteskip, offset=offset, idarray=idarray, ensemble=n_ens)

datatype() variable names: 'velocity', 'correlation', 'echo', 'percent good', 'status'.

Data shapes:

fixedleader() → (36, n_ensembles)
variableleader() → (48, n_ensembles)
datatype() → (beams, cells, n_ensembles)

Velocity is in mm/s with −32768 as the missing value sentinel. All other functions return raw integer counts.

Error Handling

Every function returns an error code as the last element of its return tuple.

data, n_ens, err = pd0_parser.fixedleader('deployment.000')

if err != 0:
    print(pd0_parser.ErrorCode.get_message(err))

Code	Name	Description
0	`SUCCESS`	Completed successfully
1	`FILE_NOT_FOUND`	File does not exist
2	`PERMISSION_DENIED`	Access denied
3	`IO_ERROR`	File open or read failed
4	`OUT_OF_MEMORY`	Insufficient memory
5	`WRONG_ADCPFILE_TYPE`	Not a valid RDI PD0 file
6	`ID_NOT_FOUND`	Data type ID not found in ensemble
7	`DATATYPE_MISMATCH`	Inconsistent data types across ensembles
8	`FILE_CORRUPTED`	Invalid structure or truncated data
9	`VALUE_ERROR`	Invalid argument
10	`CHECKSUM_ERROR`	Ensemble checksum failed
99	`UNKNOWN_ERROR`	Unexpected error

If a file is truncated mid-ensemble, all successfully parsed ensembles up to the point of corruption are returned along with CHECKSUM_ERROR.

pd0_parser

Functions

Usage

Error Handling

See Also