Arc-en-Sub 2022 cruise ROV VICTOR Navigation (M. Andreani & J. Escartin)

ROV Victor navigation is acquired during the cruise and post-processed by IFREMER post-cruise. Both the shipboard and the post-processed navigation data show inconsistencies and errors such as gaps.  A final navigation file is provided and contains location of the vehicle based primarily on the post-processed navigation, altitude and depth of the vehicle based on the ROV onboard data, and of the CTD temperature. This navigation is used to geolocate all cruise observations, samples, and measurements, and is considered as the reference.

The onboard data extracted from the ROV data streams (shipboard navigation), and the post-processed navigations, with files for each individual dive, are also provided for reference.

For the final navigation, files with a sampling rate of 1-second and a subsampled 1-minute record are provided. 

Corrections include:

- Standardisation of flags and no-data values (NaN)

- Fill major gaps in post-processed navigation with location from ROV shipboard locations

- Interpolation of minor gaps in either the shipboard or the post-processed navigation

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1.- Table with summary ROV dive information (dates, times, dive times, track lengths) in Excel .xlsx and comma separated values .csv

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Files:

AES_ROV_Dives.xlsx

AES_ROV_Dives.csv

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2.- ROV VICTOR final navigation files 

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We provide a 1-s and a 1-m final navigation file, combining all dives in each case, that will be considered as the reference navigation for the cruise, and will provide the location for all samples and observations.

The navigation files are named:

AES_ROVNav_Final_1s.txt

AES_ROVNav_Final_1m.txt

These files are obtained from the IFREMER renavigated files for the vehicle position, and from shipboard data for other parameters. Corrections include removal of flags (use of NaNs instead), interpolation for short data gaps in the processed files, and the use of shipboard navigation data to fill larger data gaps from the processed files. The vehicle depth and altitude are those from the ROV streams.

Both files are text tables with the following columns:

1 - Dive number

2 - Absolute date (from datenum matlab function)

3 4 5 - Year month day

6 7 8 - hour minute second

9 10 - Lat Lon Final (renav+filled phins gaps)

11 - Depth Final (ship)

12 - Altitude (ship)

13 - Temperature, °C

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3.- ROV VICTOR navigation files extracted onboard from the ROV data streams (NMEA files).

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Individual navigation and ROV data files were created onboard and are provided in a single compressed file:

ARCENSUB_Victor_ShipboardNav.zip

This file contains a navigation and data file for each dive, named

AES_VXXX_2205DDHHMM_victor_nav_sensors.txt

where XXX is the absolute dive number, followed by the year (22), month (05), day (DD), hour (HH) and minute (MM) 

The columns, given in the first line of the file, include at a 0,5s interval:  

#YEAR MONTH DAY HOUR MIN SEC 

LAT LON DEPTH ALT 

HEADING ROLL PITCH 

VEL_X VEL_Y VEL_Z 

TEMP(CelsiusDeg)

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4.- Processed ROV VICTOR navigation (DELPHINS processing by IFREMER)

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Processed navigation files provided by IFREMER, together with a report, are provided in a single compressed file:

ARCENSUB_Victor_ProcessedNav.zip

This file includes:

- The processing report: 22_128-Compte-rendu-traitement-Mission-AES-V.pdf

- Navigation files for each dive named AES_V_XXX_YY.txt where XXX is the absolute dive number and YY the incremental cruise dive number

- Map of the navigation for each dive named AES_V_XXX_YY.jpg (naming as above)

Each navigation file includes the following parameters acquired every 0.5s:

date     time    

latitude    longitude    immersion    

heading        pitch        roll    

eastingSd    northingSd    immersionS    

headingSd    pitchSd        rollSd