Trouble with Dolfyn reading Nortek ad2cp files #468

Greg-Ellis-NOAA · 2026-10-13T20:00:28Z

Greg-Ellis-NOAA
Oct 13, 2026

Hi all,
I've used Dolfyn for a while now to read Teledyne ENX files and it's worked flawlessly for that. Recently I've been tasked with processing some Nortek data in SigVM files. I believe the instrument is a Signature 1000; I know it has an integrated echosounder (which may be the issue here, but also may not).

I've pulled the ad2cp files from the SigVM archives and tried reading them with Dolfyn, but the resulting netCDFs only contain the first time element. I can open the files in Nortek VM Review and all time elements are read, so the files don't appear to be flawed. I've tried 'reset index', but that hasn't solved things.

My guess is this is a rookie error since I haven't used SigVM/ad2cp files before. Anybody have any guesses where this is going wrong?

thanks in advance,
Greg

jmcvey3 · 2026-10-13T20:25:54Z

jmcvey3
Oct 13, 2026
Maintainer

Hi @Greg-Ellis-NOAA, thank you for your interest in MHKiT-Dolfyn and bringing up this issue.

It's not you, reading SigVM-generated ad2cp files has been a work in progress as Nortek has been making small changes with each firmware update.
Can you read your files again with debug=True and share the output? That'll create a "*.dolfyn.log" text file and give me some idea of what is getting skipped.

0 replies

Greg-Ellis-NOAA · 2026-10-13T20:45:02Z

Greg-Ellis-NOAA
Oct 13, 2026
Author

Thanks for the quick reply! Here's the contents of the log file dolfyn generated when attempting to read one of the offending files:

root - INFO - 5641: A5, 10, 15, 2392, 0, 1, 1

root - INFO - 8043: A5, 10, 1C, 774, 0, 1, 1

root - INFO - 8827: A5, 10, 1C, 774, 1, 2, 2

root - DEBUG - Lost sync byte at pos: 9611

root - DEBUG - Header is not 10 or 12 bytes: 9611

root - INFO - No new header configuration string found
root - DEBUG - Lost sync byte at pos: 12065

root - DEBUG - Header is not 10 or 12 bytes: 12065

root - DEBUG - Lost sync byte at pos: 37777

root - DEBUG - Header is not 10 or 12 bytes: 37777

root - DEBUG - Lost sync byte at pos: 39331

root - DEBUG - Header is not 10 or 12 bytes: 39331

root - DEBUG - Lost sync byte at pos: 41050

root - DEBUG - Header is not 10 or 12 bytes: 41050

root - INFO - Invalid skip byte at pos: 41050

1 reply

jmcvey3 Oct 13, 2026
Maintainer

This is surprising to me... This says that Dolfyn successfully read a velocity ping ("15") followed by two echosounder pings ("1C"), but then the next several bytes weren't the header of the next ping.

Do all of your files fail in the same way? And if so, can you share one of them?

Greg-Ellis-NOAA · 2026-10-14T15:56:31Z

Greg-Ellis-NOAA
Oct 14, 2026
Author

All of the files have the same symptom: the only read the first time value.

The uploader does not like .ad2cp files (or presumably SigVM files either) so I've re-named an example SigVM to .zip and attached it.
106184_20261006T015132UTC.zip

Thanks for all your help!
-Greg

0 replies

simmsa · 2026-10-14T16:58:53Z

simmsa
Oct 14, 2026
Maintainer

Hi @Greg-Ellis-NOAA,

I was able to read this file in the latest version of MHKiT installed via conda install -c conda-forge mhkit and running the following code:

import mhkit

mhkit.__version__

'v1.1.1'

ds = mhkit.dolfyn.read("./data/106184_20261006T015132UTC.AD2CP")

Reading file ./data/106184_20261006T015132UTC.AD2CP ...

ds.info()

xarray.Dataset {
dimensions:
	time = 1 ;
	time_echo = 1 ;
	range = 139 ;
	range_echo = 317 ;
	beam = 4 ;
	dir = 4 ;
	dirIMU = 3 ;
	earth = 3 ;
	inst = 3 ;
	q = 4 ;
	x1 = 4 ;
	x2 = 4 ;

variables:
	datetime64[ns] time(time) ;
		time:coverage_content_type = coordinate ;
		time:units = seconds since 1970-01-01 00:00:00 ;
		time:long_name = Time ;
		time:standard_name = time ;
	datetime64[ns] time_echo(time_echo) ;
		time_echo:coverage_content_type = coordinate ;
		time_echo:units = seconds since 1970-01-01 00:00:00 ;
		time_echo:long_name = Time echo ;
		time_echo:standard_name = time ;
	float64 range(range) ;
		range:coverage_content_type = coordinate ;
		range:units = m ;
		range:long_name = Profile Range ;
		range:description = Distance to the center of each depth bin ;
	float64 range_echo(range_echo) ;
		range_echo:coverage_content_type = coordinate ;
		range_echo:units = m ;
		range_echo:long_name = Profile Range echo ;
		range_echo:description = Distance to the center of each depth bin ;
	int32 beam(beam) ;
		beam:units = 1 ;
		beam:long_name = Beam Reference Frame ;
		beam:coverage_content_type = coordinate ;
	int32 dir(dir) ;
		dir:units = 1 ;
		dir:long_name = Reference Frame ;
		dir:coverage_content_type = coordinate ;
		dir:ref_frame = beam ;
	float32 c_sound(time) ;
		c_sound:units = m s-1 ;
		c_sound:long_name = Speed of Sound ;
		c_sound:standard_name = speed_of_sound_in_sea_water ;
	float32 temp(time) ;
		temp:units = degree_C ;
		temp:long_name = Temperature ;
		temp:standard_name = sea_water_temperature ;
	float32 pressure(time) ;
		pressure:units = dbar ;
		pressure:long_name = Pressure ;
		pressure:standard_name = sea_water_pressure ;
	float32 heading(time) ;
		heading:units = degree ;
		heading:long_name = Heading ;
		heading:standard_name = platform_orientation ;
	float32 pitch(time) ;
		pitch:units = degree ;
		pitch:long_name = Pitch ;
		pitch:standard_name = platform_pitch ;
	float32 roll(time) ;
		roll:units = degree ;
		roll:long_name = Roll ;
		roll:standard_name = platform_roll ;
	<U1 dirIMU(dirIMU) ;
		dirIMU:units = 1 ;
		dirIMU:long_name = Reference Frame ;
		dirIMU:coverage_content_type = coordinate ;
		dirIMU:ref_frame = beam ;
	float32 mag(dirIMU, time) ;
		mag:units = uT ;
		mag:coverage_content_type = physicalMeasurement ;
		mag:long_name = Compass ;
	float32 accel(dirIMU, time) ;
		accel:units = m s-2 ;
		accel:coverage_content_type = physicalMeasurement ;
		accel:long_name = Acceleration ;
	float32 batt(time) ;
		batt:units = V ;
		batt:long_name = Battery Voltage ;
		batt:standard_name = battery_voltage ;
	float32 temp_clock(time) ;
		temp_clock:units = degree_C ;
		temp_clock:long_name = Internal Clock Temperature ;
	uint16 error(time) ;
		error:units = 1 ;
		error:long_name = Error Code ;
	uint32 status(time) ;
		status:units = 1 ;
		status:long_name = Status Code ;
	uint32 ensemble(time) ;
		ensemble:units = # ;
		ensemble:long_name = Ensemble Number ;
		ensemble:standard_name = number_of_observations ;
	float32 vel(dir, range, time) ;
		vel:units = m s-1 ;
		vel:coverage_content_type = physicalMeasurement ;
		vel:long_name = Water Velocity ;
	float32 amp(beam, range, time) ;
		amp:units = 1 ;
		amp:coverage_content_type = physicalMeasurement ;
		amp:long_name = Acoustic Signal Amplitude ;
		amp:standard_name = signal_intensity_from_multibeam_acoustic_doppler_velocity_sensor_in_sea_water ;
	uint8 corr(beam, range, time) ;
		corr:units = % ;
		corr:coverage_content_type = physicalMeasurement ;
		corr:long_name = Acoustic Signal Correlation ;
		corr:standard_name = beam_consistency_indicator_from_multibeam_acoustic_doppler_velocity_profiler_in_sea_water ;
	<U1 earth(earth) ;
		earth:units = 1 ;
		earth:long_name = Earth Reference Frame ;
		earth:coverage_content_type = coordinate ;
	<U1 inst(inst) ;
		inst:units = 1 ;
		inst:long_name = Instrument Reference Frame ;
		inst:coverage_content_type = coordinate ;
	float32 orientmat(earth, inst, time) ;
		orientmat:units = 1 ;
		orientmat:coverage_content_type = physicalMeasurement ;
		orientmat:long_name = Orientation Matrix ;
	float32 angrt(dirIMU, time) ;
		angrt:units = rad s-1 ;
		angrt:coverage_content_type = physicalMeasurement ;
		angrt:long_name = Angular Velocity ;
	<U1 q(q) ;
		q:units = 1 ;
		q:long_name = Quaternion Vector Components ;
		q:coverage_content_type = coordinate ;
	float32 quaternions(q, time) ;
		quaternions:units = 1 ;
		quaternions:coverage_content_type = physicalMeasurement ;
		quaternions:long_name = Quaternions ;
	float32 pressure_alt(time) ;
		pressure_alt:units = dbar ;
		pressure_alt:long_name = Pressure measured during AST ping ;
		pressure_alt:standard_name = sea_water_pressure ;
	float32 le_dist_alt(time) ;
		le_dist_alt:units = m ;
		le_dist_alt:long_name = Altimeter Range Leading Edge Algorithm ;
		le_dist_alt:standard_name = altimeter_range ;
	float32 le_quality_alt(time) ;
		le_quality_alt:units = dB ;
		le_quality_alt:long_name = Altimeter Quality Indicator Leading Edge Algorithm ;
	uint16 status_alt(time) ;
		status_alt:units = 1 ;
		status_alt:long_name = Altimeter Status ;
	float32 ast_dist_alt(time) ;
		ast_dist_alt:units = m ;
		ast_dist_alt:long_name = Altimeter Range Acoustic Surface Tracking ;
		ast_dist_alt:standard_name = altimeter_range ;
	float32 ast_quality_alt(time) ;
		ast_quality_alt:units = dB ;
		ast_quality_alt:long_name = Altimeter Quality Indicator Acoustic Surface Tracking ;
	float32 ast_offset_time_alt(time) ;
		ast_offset_time_alt:units = s ;
		ast_offset_time_alt:long_name = Acoustic Surface Tracking Time Offset to Velocity Ping ;
	float32 temp_press(time) ;
		temp_press:units = degree_C ;
		temp_press:long_name = Pressure Sensor Temperature ;
	uint16 xmit_energy(time) ;
		xmit_energy:units = dB ;
		xmit_energy:long_name = Sound Pressure Level of Acoustic Signal ;
	float32 c_sound_echo(time_echo) ;
		c_sound_echo:units = m s-1 ;
		c_sound_echo:long_name = Speed of Sound ;
		c_sound_echo:standard_name = speed_of_sound_in_sea_water ;
	float32 temp_echo(time_echo) ;
		temp_echo:units = degree_C ;
		temp_echo:long_name = Temperature ;
		temp_echo:standard_name = sea_water_temperature ;
	float32 pressure_echo(time_echo) ;
		pressure_echo:units = dbar ;
		pressure_echo:long_name = Pressure ;
		pressure_echo:standard_name = sea_water_pressure ;
	float32 heading_echo(time_echo) ;
		heading_echo:units = degree ;
		heading_echo:long_name = Heading ;
		heading_echo:standard_name = platform_orientation ;
	float32 pitch_echo(time_echo) ;
		pitch_echo:units = degree ;
		pitch_echo:long_name = Pitch ;
		pitch_echo:standard_name = platform_pitch ;
	float32 roll_echo(time_echo) ;
		roll_echo:units = degree ;
		roll_echo:long_name = Roll ;
		roll_echo:standard_name = platform_roll ;
	float32 mag_echo(dirIMU, time_echo) ;
		mag_echo:coverage_content_type = physicalMeasurement ;
		mag_echo:units = uT ;
		mag_echo:long_name = Compass ;
	float32 accel_echo(dirIMU, time_echo) ;
		accel_echo:coverage_content_type = physicalMeasurement ;
		accel_echo:units = m s-2 ;
		accel_echo:long_name = Acceleration ;
	float32 batt_echo(time_echo) ;
		batt_echo:units = V ;
		batt_echo:long_name = Battery Voltage ;
		batt_echo:standard_name = battery_voltage ;
	float32 temp_clock_echo(time_echo) ;
		temp_clock_echo:units = degree_C ;
		temp_clock_echo:long_name = Internal Clock Temperature ;
	uint16 error_echo(time_echo) ;
		error_echo:units = 1 ;
		error_echo:long_name = Error Code ;
	uint32 status_echo(time_echo) ;
		status_echo:units = 1 ;
		status_echo:long_name = Status Code ;
	uint32 ensemble_echo(time_echo) ;
		ensemble_echo:units = # ;
		ensemble_echo:long_name = Ensemble Number ;
		ensemble_echo:standard_name = number_of_observations ;
	float32 orientmat_echo(earth, inst, time_echo) ;
		orientmat_echo:units = 1 ;
		orientmat_echo:coverage_content_type = physicalMeasurement ;
		orientmat_echo:long_name = Orientation Matrix ;
	float32 angrt_echo(dirIMU, time_echo) ;
		angrt_echo:coverage_content_type = physicalMeasurement ;
		angrt_echo:units = rad s-1 ;
		angrt_echo:long_name = Angular Velocity ;
	float32 quaternions_echo(q, time_echo) ;
		quaternions_echo:units = 1 ;
		quaternions_echo:coverage_content_type = physicalMeasurement ;
		quaternions_echo:long_name = Quaternions ;
	float32 temp_press_echo(time_echo) ;
		temp_press_echo:units = degree_C ;
		temp_press_echo:long_name = Pressure Sensor Temperature ;
	uint16 xmit_energy_echo(time_echo) ;
		xmit_energy_echo:units = dB ;
		xmit_energy_echo:long_name = Sound Pressure Level of Acoustic Signal ;
	uint8 low_volt_skip(time) ;
	uint8 active_config(time) ;
	uint8 telemetry_data(time) ;
	uint8 boost_running(time) ;
	float32 echo(range_echo, time_echo) ;
		echo:units = dB ;
		echo:coverage_content_type = physicalMeasurement ;
		echo:long_name = Echo Sounder Acoustic Signal Backscatter ;
		echo:standard_name = acoustic_target_strength_in_sea_water ;
	int32 x1(x1) ;
		x1:coverage_content_type = coordinate ;
	int32 x2(x2) ;
		x2:coverage_content_type = coordinate ;
	float32 beam2inst_orientmat(x1, x2) ;
		beam2inst_orientmat:units = 1 ;
		beam2inst_orientmat:coverage_content_type = physicalMeasurement ;
		beam2inst_orientmat:long_name = Rotation Matrix ;

// global attributes:
	:filehead_config = {"CLOCKSTR": {"TIME": "\"2026-10-06 01:50:34\""}, "ID": "STR=\"Signature500\",SN=106184", "HW": {"FW": 3057, "FPGA": 187, "DIGITAL": "\"I-6\"", "INTERFACE": "\"J-1\"", "ANALOG": "\"B-0(Low-Power EDR500)\"", "SENSOR": "\"E-0(AHRS)\"", "BOOT": 25, "FWMINOR": 8}, "BOARDSENSGET": "AV=23,NB=5,HF=500,TTR=2.0000,TTRB5=2.0000,TTRB5AUX=0.0000,AUXRS=0", "PWR": {"PLAN": 4902.41, "BURST": 4661.31, "AVG": 0.0, "PLAN1": 0.0, "BURST1": 0.0, "AVG1": 0.0, "TOTAL": 4902.41}, "MEM": {"PLAN": 14.447, "BURST": 14.447, "AVG": 0.0, "PLAN1": 0.0, "BURST1": 0.0, "AVG1": 0.0, "TOTAL": 14.447}, "PRECISION": {"AVGHORZ": -9.99, "BURSTHORZ": 10.95, "BEAM5": -9.99, "AVGBEAM": -9.99, "BURSTBEAM": 6.54}, "PLAN": {"MIAVG": 0, "AVG": 0, "DIAVG": 0, "VD": 0, "MV": 0, "SA": 0.0, "BURST": 1, "MIBURST": 0, "DIBURST": 0, "SV": 1474.0, "FN": "\"\"", "SO": 1, "FREQ": 500, "NSTT": 0}, "BURST": {"NC": 139, "NB": 4, "CS": 0.5, "BD": 0.5, "CY": "\"BEAM\"", "PL": 0.0, "SR": 1, "NS": 7200, "VR": 5.0, "VP": 0.0, "DF": 3, "NPING": 0, "CH": 0, "ALTI": 1, "VR5": 5.0, "BT": 1, "DISV": 0, "ECHO": 1, "RAWALTI": 0, "ALTISTART": 0.5, "ALTIEND": 77.8, "HR": 0, "HR5": 0}, "XFBURST": {"ROWS": 4, "COLS": 4, "M11": 1.1831, "M12": 0.0, "M13": -1.1831, "M14": 0.0, "M21": 0.0, "M22": -1.1831, "M23": 0.0, "M24": 1.1831, "M31": 0.5518, "M32": 0.0, "M33": 0.5518, "M34": 0.0, "M41": 0.0, "M42": 0.5518, "M43": 0.0, "M44": 0.5518}, "READALTIBURST": "EN=1,START=0.50,END=77.80,SAMPSIZE=0.024,NB=1,NSAMP=3220,RAW=0", "BT": {"RANGE": 70.0, "VR": 5.0, "NB": 4, "CH": 0, "DF": 199, "PL": 0.0}, "XFBT": {"ROWS": 4, "COLS": 4, "M11": 1.1831, "M12": 0.0, "M13": -1.1831, "M14": 0.0, "M21": 0.0, "M22": -1.1831, "M23": 0.0, "M24": 1.1831, "M31": 0.5518, "M32": 0.0, "M33": 0.5518, "M34": 0.0, "M41": 0.0, "M42": 0.5518, "M43": 0.0, "M44": 0.5518}, "CHO": {"BINSIZE": 0.2, "NC": 317, "BD": 0.5, "DF": 3, "FREQ1": 500, "NBINF1": 1, "XMIT1": 0.1, "PL1": 0.0, "FREQ2": 500, "NBINF2": 1, "XMIT2": 0.1, "PL2": 0.0, "FREQ3": 0, "NBINF3": 1, "XMIT3": 0.032, "PL3": -12.0, "PULSECOMP1": 1, "PULSECOMP2": 0, "PULSECOMP3": 0, "CH1": 0, "CH2": 0, "CH3": 0, "RAW1": 0, "RAW2": 0, "RAW3": 0}, "READECHO": "NRAWSAMP1=0,NRAWSAMP2=0,NRAWSAMP3=0,NRAWXMIT1=0,NRAWXMIT2=0,NRAWXMIT3=0,SAMPFREQ1=0.0,SAMPFREQ2=0.0,SAMPFREQ3=0.0,RANGESTART1=0.000,RANGESTART2=0.000,RANGESTART3=0.000", "PTPGET": "EN=2,OFFSET=0,CL=1791251434,SS=2,SOM=27.660000,IP=\"172.30.0.101\"", "USER": {"POFF": 9.5, "DECL": 0.0, "HX": 0, "HY": 0, "HZ": 0}, "INST": {"BR": 115200, "RS": 232, "LED": "\"ON24H\"", "ORIENT": "\"AHRS3D\"", "CMTOUT": 300, "DMTOUT": 60, "CFMTOUT": 60}, "COMPASSCAL": {"DX": -54, "DY": 1373, "DZ": 788, "M11": 31985, "M12": 1183, "M13": 640, "M21": -1522, "M22": 32767, "M23": 105, "M31": -513, "M32": -934, "M33": 31792}, "READAHRS": "STR=\"OSv6_a2_V5101_0.6 Oct  3 2019, SerialNumber=60006391,type=OS3DM\"", "RECSTAT": "SS=512,CS=32768,FC=61991092224,TC=62260248576,VS=62260248576,FF=4095,TF=4095", "BEAMCFGLIST": ["BEAM=1,THETA=25.00,PHI=0.00,FREQ=500,BW=25,BRD=1,HWBEAM=1,ZNOM=100.00,DIA=0.0", "BEAM=2,THETA=25.00,PHI=-90.00,FREQ=500,BW=25,BRD=1,HWBEAM=2,ZNOM=100.00,DIA=0.0", "BEAM=3,THETA=25.00,PHI=180.00,FREQ=500,BW=25,BRD=1,HWBEAM=3,ZNOM=100.00,DIA=0.0", "BEAM=4,THETA=25.00,PHI=90.00,FREQ=500,BW=25,BRD=1,HWBEAM=4,ZNOM=100.00,DIA=0.0", "BEAM=5,THETA=0.00,PHI=0.00,FREQ=500,BW=25,BRD=1,HWBEAM=5,ZNOM=100.00,DIA=0.0"], "BEAMIMPLIST": ["BEAM=1,P0=1.00000e+02,P1=0.00000e+00,P2=0.00000e+00,P3=0.00000e+00,P4=0.00000e+00,T1=0.00000e+00", "BEAM=2,P0=1.00000e+02,P1=0.00000e+00,P2=0.00000e+00,P3=0.00000e+00,P4=0.00000e+00,T1=0.00000e+00", "BEAM=3,P0=1.00000e+02,P1=0.00000e+00,P2=0.00000e+00,P3=0.00000e+00,P4=0.00000e+00,T1=0.00000e+00", "BEAM=4,P0=1.00000e+02,P1=0.00000e+00,P2=0.00000e+00,P3=0.00000e+00,P4=0.00000e+00,T1=0.00000e+00", "BEAM=5,P0=1.00000e+02,P1=0.00000e+00,P2=0.00000e+00,P3=0.00000e+00,P4=0.00000e+00,T1=0.00000e+00"], "LISTLICENSE": ["KEY=\"MF9FHERB9C4JB\",DESC=\"Averaging Mode\",TYPE=1", "KEY=\"PZ2XKSPBAC4JB\",DESC=\"Burst Five Beams\",TYPE=17", "KEY=\"XNZTCE0S9C4JB\",DESC=\"Echo Sounder\",TYPE=16", "KEY=\"XZHEW3W59C4JB\",DESC=\"Altimeter\",TYPE=5", "KEY=\"A7DR34HN9C4JB\",DESC=\"Bottom Track\",TYPE=3", "KEY=\"F0TSNXTJ9C4JB\",DESC=\"64GB Recorder\",TYPE=10"], "CALCOMPGET": "DX=-54,DY=1373,DZ=788,M11=31985,M12=1183,M13=640,M21=-1522,M22=32767,M23=105,M31=-513,M32=-934,M33=31792", "CALTEMPGET": "SC=0.99862", "CALTILTGET": "PO=0.00,RO=0.00,MAGG=1,HO=0.00", "CALACCLGET": ["AX=1.000000E+00,B0X=1.218281E-02,B1X=-1.663948E-02,B2X=-2.463835E-05,B3X=0.000000E+00,A1X=-2.760014E-06,A2X=-1.865896E-06,A3X=0.000000E+00", "AY=1.000000E+00,B0Y=1.545032E-02,B1Y=-2.265849E-02,B2Y=1.040071E-04,B3Y=0.000000E+00,A1Y=-4.891953E-05,A2Y=-1.180920E-05,A3Y=0.000000E+00", "AZ=1.000000E+00,B0Z=-1.800108E-03,B1Z=-3.787998E-02,B2Z=1.206056E-03,B3Z=0.000000E+00,A1Z=7.903599E-05,A2Z=-4.352524E-06,A3Z=0.000000E+00"], "CALGYROGET": ["AX=1.091562E+00,B0X=-6.780021E-01,B1X=-7.789508E-04,B2X=-1.751632E-05,B3X=0.000000E+00,A1X=2.080470E-03,A2X=-3.195554E-05,A3X=0.000000E+00", "AY=1.088448E+00,B0Y=1.284875E+00,B1Y=1.799449E-03,B2Y=4.871935E-05,B3Y=0.000000E+00,A1Y=3.053993E-04,A2Y=2.147257E-05,A3Y=0.000000E+00", "AZ=1.089771E+00,B0Z=-2.903984E-01,B1Z=6.355124E-04,B2Z=-3.948808E-07,B3Z=0.000000E+00,A1Z=9.575710E-04,A2Z=-9.268521E-06,A3Z=0.000000E+00"], "CALPRESSGET": "MT=0,RREF=4.5305845000e+02,RB0=5.7080718750e-02,RB1=-2.1004250000e-01,RB2=4.3226900000e-04,RB3=1.1038320000e-08,T0=-3.0210630000e+03,T1=2.2654200000e+00,T2=-5.8136431250e-04,T3=5.2217818750e-08,ID=\"R092901\"", "CALPRESSCOEFFGET": ["A0=1.5071329690e-01,A1=4.8018050000e-04,A2=-1.2420560160e-07,A3=1.0782638750e-11,B0=-7.9858443750e-01,B1=7.7269675000e-04,B2=-2.1415359380e-07,B3=1.9671789060e-11", "C0=9.0947643750e-04,C1=-7.7158350000e-07,C2=2.2132520310e-10,C3=-2.1262498440e-14,D0=-2.4552500000e-06,D1=2.0495839060e-09,D2=-5.7710418750e-13,D3=5.4482556250e-17"], "CALROTACCLGET": "M11=0.99653,M12=0.00147,M13=-0.00346,M21=-0.00475,M22=0.99356,M23=-0.00031,M31=-0.00309,M32=-0.00456,M33=0.97713", "CALROTGYROGET": "M11=1.00000,M12=-0.00161,M13=-0.00094,M21=-0.00029,M22=1.00000,M23=-0.00177,M31=-0.00014,M32=0.00233,M33=1.00000", "CALECHOGET": "CHA0=0.00,CHB0=-15.38,CHC0=0.00"} ;
	:inst_model = Signature500 ;
	:inst_make = Nortek ;
	:inst_type = ADCP ;
	:burst_config = {"press_valid": true, "temp_valid": true, "compass_valid": true, "tilt_valid": true, "vel": true, "amp": true, "corr": true, "le": true, "altraw": false, "ast": true, "echo": false, "ahrs": true, "p_gd": false, "std": false} ;
	:n_cells = 139 ;
	:n_beams = 4 ;
	:ambig_vel = 10.236 ;
	:SerialNum = 106184 ;
	:nominal_corr = 67 ;
	:cell_size = 0.5 ;
	:blank_dist = 0.5 ;
	:power_level_dB = 0.0 ;
	:burst_config_echo = {"press_valid": true, "temp_valid": true, "compass_valid": true, "tilt_valid": true, "vel": false, "amp": false, "corr": false, "le": false, "altraw": false, "ast": false, "echo": true, "ahrs": true, "p_gd": false, "std": false} ;
	:n_cells_echo = 317 ;
	:n_beams_echo = 0 ;
	:ambig_vel_echo = 5.0 ;
	:SerialNum_echo = 106184 ;
	:nominal_corr_echo = 0 ;
	:cell_size_echo = 0.2 ;
	:blank_dist_echo = 0.5 ;
	:power_level_dB_echo = 0.0 ;
	:wakeup_state = break ;
	:orientation = AHRS ;
	:orient_status = AHRS-3D ;
	:proc_idle_less_3pct = 0 ;
	:proc_idle_less_6pct = 0 ;
	:proc_idle_less_12pct = 0 ;
	:rotate_vars = ['vel', 'accel', 'accel_echo', 'angrt', 'angrt_echo', 'mag', 'mag_echo'] ;
	:coord_sys = beam ;
	:fs = 1 ;
	:has_imu = 1 ;
	:beam_angle = 25 ;
}

And saving the file yields:

mhkit.dolfyn.save(ds. "data/106184_20261006T015132UTC.nc")

opt/homebrew/lib/python3.11/site-packages/mhkit/dolfyn/io/api.py:223: UserWarning: Times can't be serialized faithfully to int64 with requested units 'seconds since 1970-01-01'. Resolution of 'nanoseconds' needed. Serializing times to floating point instead. Set encoding['dtype'] to integer dtype to serialize to int64. Set encoding['dtype'] to floating point dtype to silence this warning.
  ds.to_netcdf(filename, format=format, engine=engine, **kwargs)
/opt/homebrew/lib/python3.11/site-packages/mhkit/dolfyn/io/api.py:223: UserWarning: Times can't be serialized faithfully to int64 with requested units 'seconds since 1970-01-01'. Resolution of 'nanoseconds' needed. Serializing times to floating point instead. Set encoding['dtype'] to integer dtype to serialize to int64. Set encoding['dtype'] to floating point dtype to silence this warning.
  ds.to_netcdf(filename, format=format, engine=engine, **kwargs)

106184_20261006T015132UTC.nc.zip

In the attached zipped nc file

The output of dolfyn has 1 timestamp and did not yield any errors:

The 1 timestamp seems like an unexpected result and also the output nc file is much smaller than the input .AD2CP file . Can you confirm you are expecting more than 1 timestamp?

0 replies

simmsa · 2026-10-14T17:06:05Z

simmsa
Oct 14, 2026
Maintainer

@Greg-Ellis-NOAA, my bad. Just read through this. You are definitely seeing the same thing as my version.

0 replies

jmcvey3 · 2026-10-14T22:51:55Z

jmcvey3
Oct 14, 2026
Maintainer

Wow this one's a doozy. PR #471 will allow you to read most of the file, but not the bottom track information.
Also, it appears that the echosounder was recording at 2 Hz, while the velocity was recording at 1 Hz? Can you verify this is correct?

0 replies

Greg-Ellis-NOAA · 2026-10-15T19:02:47Z

Greg-Ellis-NOAA
Oct 15, 2026
Author

Glad you are making progress. This does not look like it's simple.

Unfortunately I was not involved with configuring the instrument- I only got the SigVM files after the fact. As such, I'm unsure of the acquisition rates.

Nortek's VM Review software shows an ensemble frequency of 1 Hz. When I look at the ground track data & echosounder, they are also reporting on a one-second basis, but I think the software may be interpolating those numbers to match the ensemble frequency.

I've attached a second, longer file that shares the same problems as the one I sent before. I discovered the first file appears to have been acquired while the vessel was moored during deployment, so even once it's read successfully, it may look strange (it only has a couple of cells above the bottom). The second one is more representative of the remainder of the mission.
106184_20261006T133711UTC.zip

thanks again!

2 replies

jmcvey3 Oct 16, 2026
Maintainer

Thanks @Greg-Ellis-NOAA for the file, that file is super helpful. Nortek was pretty quick at getting back to me on the data structure definition, but I'm still working through datatypes to read things correctly.

jmcvey3 Oct 19, 2026
Maintainer

@Greg-Ellis-NOAA Please check out PR #471 and see if that works for you. The first 3 datapoints for each variable are going to contain zeros, but I'm still working through that

Greg-Ellis-NOAA · 2026-10-20T14:33:02Z

Greg-Ellis-NOAA
Oct 20, 2026
Author

Will do, thanks- I'm travelling to a conference at the moment but I will investigate as time permits.

…

-Greg

On Mon, Oct 19, 2026 at 5:31 PM James McVey ***@***.***> wrote: @Greg-Ellis-NOAA <https://github.com/Greg-Ellis-NOAA> Please check out PR #471 <#471> and see if that works for you. The first 3 datapoints for each variable are going to contain zeros, but I'm still working through that — Reply to this email directly, view it on GitHub <#468?email_source=notifications&email_token=B7B5AM4ZHYJLY6B6BNDK7UL5U2B2ZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJQGUZDEOBTUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19052283>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B7B5AM3L33H6PE44HQUHR7T5U2B2ZAVCNFSNUABIKJSXA33TNF2G64TZHMZDEOBWG43TCOJQHNCGS43DOVZXG2LPNY5TCMJQGEYTQNBUUF3AE> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/B7B5AM7INDXE2JVLGW7MDMD5U2B2ZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJQGUZDEOBTUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/B7B5AMZ3GGWJ46PK5PUSCPT5U2B2ZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJQGUZDEOBTUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.*** .com>

-- Gregory Ellis, PhD Oceanographic Research Analyst (IBSS contractor) Northeast Fisheries Science Center (remote) 239-404-2088

0 replies

Trouble with Dolfyn reading Nortek ad2cp files #468

Uh oh!

Greg-Ellis-NOAA Oct 13, 2026

Replies: 8 comments · 3 replies

Uh oh!

jmcvey3 Oct 13, 2026 Maintainer

Uh oh!

Greg-Ellis-NOAA Oct 13, 2026 Author

Uh oh!

jmcvey3 Oct 13, 2026 Maintainer

Uh oh!

Greg-Ellis-NOAA Oct 14, 2026 Author

Uh oh!

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simmsa Oct 14, 2026 Maintainer

Uh oh!

simmsa Oct 14, 2026 Maintainer

Uh oh!

jmcvey3 Oct 14, 2026 Maintainer

Uh oh!

Greg-Ellis-NOAA Oct 15, 2026 Author

Uh oh!

jmcvey3 Oct 16, 2026 Maintainer

Uh oh!

jmcvey3 Oct 19, 2026 Maintainer

Uh oh!

Greg-Ellis-NOAA Oct 20, 2026 Author

Greg-Ellis-NOAA
Oct 13, 2026

Replies: 8 comments 3 replies

jmcvey3
Oct 13, 2026
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Greg-Ellis-NOAA
Oct 13, 2026
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jmcvey3 Oct 13, 2026
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Greg-Ellis-NOAA
Oct 14, 2026
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simmsa
Oct 14, 2026
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simmsa
Oct 14, 2026
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jmcvey3
Oct 14, 2026
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Greg-Ellis-NOAA
Oct 15, 2026
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jmcvey3 Oct 16, 2026
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jmcvey3 Oct 19, 2026
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Oct 20, 2026
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