HOVERCRAFT "SABVABAA" SEISMIC PROFILING				UNIVERSITY OF BERGEN Department of Earth Science Allé gt. 41, N-5007 Bergen, Norway

0.1	DRAFT	-	14 July, 2022	OM	OM	-
VER.	STATUS	CHANGE	DATE	BY	CKD	APPD

A 20 inch³ Bolt airgun. Click to enlarge.

Air bubbles from a shot. Click to enlarge.

SURVEY 2022

Instrumentation diagram

Drawing No. HC-001-E-G-001-1, Rev-A. Click to open PDF version.

RTM3 Trigger interface

Chassis connector, RTM3

26-pin F
Model: Souriau 851-07A16-26S50-A7

Internal wiring, RTM3 trigger connector. Source: RTM3 manual.

Matching cable connector:

26-pin M
Model: Souriau 851-06EC16-26P50
Supplier: RS, stock no: 687-6673: "Souriau, 851 26 Way Cable Mount MIL Spec Circular Connector Plug, Pin Contacts,Shell Size 16, Bayonet Coupling"

From RTM3 manual, section 12.1 "Breakout Box Diagram"

From RTM3 manual: RTM3 time stamp trigger input -- G = center coax; R = coax shield. Click to enlarge.

Backup: Installing all software on Win 11 laptop

In order to prepare for future replacement of main seismic computer -- a 2008 vintage Dell Latitude D630 laptop running WinXP -- we attempted to install all software on a modern laptop.

New laptop: Dell Latitude 7420

Laptop: Dell Latitude 7420
- Power input: USB-C
- Ethernet port: No (only WLAN). GEODE program requires Ethernet port for communication with the GEODE seismograph, so a solution must be found.
- USB-A port: 1 ea
- USB-C port: 1 ea
- HDMI port: Yes
OS: WIN11

Adapters used

4-port RS232 hub, from USB-A
- Aten mod UC2324-AT
- Supplier: Dustin, P/N: 5010330045)
4-port USB-A hub, from USB-C
- Plexgear Portable 420 USB 3.0-hub 4-way
- Supplier: Kjell & Co, P/N: 69515
Ethernet adapter, from USB-A
- LevelOne, mod USB-0301 (H/W Ver: 1.0)
- Supplier:

Installing Python interpreter and three libraries

PYTHON INTERPRETER:

Using ver 2.7.17 dated Oct 19,2019 (presumably last 2.7 version of Python)
https://www.python.org/downloads/release/python-2717/
Link to python-2.7.17.msi Windows x86 MSI installer

EXTERNAL LIBRARIES REQUIRED:

Install three libraries:

First open terminal window, then use these commands (assuming Python interpreter was installed in default directory, c:\Python27\):

 cd c:\Python27 .\python -m pip install -U pip
 .\python -m pip install pyserial==2.7
 .\python -m pip install psutil

Installing GEODE software

https://www.geometrics.com/wp-content/uploads/2018/10/SCS_Installation.zip

Install GNSS/Survey logger, and Mini-GUNCO software, in two new directories

In terminal window:

 cd c: mkdir HOVERCRAFT_GPS_2022
 mkdir HOVERCRAFT_GUNCO_2022

Download:

gunco-ver4-2022-07-13.py to HOVERCRAFT_GUNCO_2022
gunco.ini to HOVERCRAFT_GUNCO_2022
hovercraft-GNSS-ver3-2020-07-13.py to HOVERCRAFT_GPS_2022

Run the programs, in separate terminal windows:

Terminal window #1:

 cd c:\HOVERCRAFT_GPS_2022
 c:\python27\python .\hovercraft-GNSS-ver3-2020-07-13.py

Terminal window #2:

 cd c:\HOVERCRAFT_GUNCO_2022
 c:\python27\python .\gunco-ver4-2022-07-13.py

Screenshot

13 July, 2022: Three programs operating on WIN11 laptop:
            (a) GNSS Distributor/Survey logger;
            (b) Mini-GUNCO program;
            (c) GEODE program.
Red arrow marks how Mini-Gunco program exports serial RS232 Shotpoint event data, which are captured by GEODE program (using separate COM-port). The event data string looks like NMEA telegram, starting with "$PUIBNAV", where means P="Proprietary", UIB="Universitetet i Bergen", and NAV="Navigation data". Click to enlarge.

SURVEY 2020

Laptops, 2x

Mfr: Dell
Model: Latitude D630
OS: Win XP
Software updates, May 2020:
- Python ver 2.7.18: https://www.python.org/downloads/release/python-2718/
- PySerial ver 2.7: https://pypi.org/project/pyserial/2.7/ --- pyserial-2.7.win32.exe (270.2 kB)
- Notepad++: https://notepad-plus-plus.org/downloads/v7.8.6/
- TeraTerm: https://osdn.net/projects/ttssh2/downloads/72009/teraterm-4.105.exe/

GNSS units

Navilock NL-8004U USB 2.0 GNSS Receiver

Manufacturer: NaviLock
Model: P/N: 62531 "Navilock NL-8004U USB 2.0 Multi GNSS Receiver u-blox 8 4.5 m"
Cable length: ca. 4.5 m
Connector: USB 2.0 Type-A male
Data sheet: Link -- also local copy
User Manual --- also local copy
Suppliers:
More detailed telegram information
Chipset: u-blox 8 UBX-M8030-KT
- About ubx-m8030-series
- Listing of Document resources
- Interface Manual --- u-blox 8 / u-blox M8 Receiver Description, Including Protocol Specification ---- also local copy Δ
- UBX-M8030 Product Summary --- also local copy.
- 72-channel u-blox M8 engineGPS/QZSS L1 C/A, GLONASS L10FBeiDou B1, Galileo E1B/CSBAS L1 C/A: WAAS, EGNOS, MSAS, GAGAN

Time stamping of airgun firing

Remote Trigger Module 3, or RTM3, made by Seismic Source Company
Ethernet: The RTM3 has a fixed IP and not a DHCP server. If the RTM has a serial number of 171 the IP address will be, 10.0.1.71. The computer should be set to 10.0.0.101. This link shows a video on setting up the computer IP address: https://www.youtube.com/channel/UCWszOSFMYMt20E-d2CD4xvQ
Display: The "1" is the GPS indicator value from the NMEA string, $GPGGA, that is being received by the RTM3 and sent by the GPS receiver. The "P" means that the RTM3 is receiving the PPS from the GPS receiver. The "T:OK" means the RTM3 is time synchronized with the GPS receiver’s NMEA messages and PPS.

Under consideration: https://verif-i.com/product/gps-sync/

GEODE seismic recorder

Hardware

Trigger Interface cable: Item: 0026960-10 "CBL ASSY, TRIGGER (BNC TO 3-PIN) CO: SN030437

Software

Product link: https://www.geometrics.com/product/geode-exploration-seismograph/
Manual: https://geometrics.com/wp-content/uploads/2019/03/Geode-NZ-SmartSeis-ES-3000-Operations-Manual.pdf
Software: https://www.geometrics.com/software/ -- Seismodule Controller Software (SCS) -- https://geometrics.com/wp-content/uploads/2018/10/SCS_Installation.zip

USB to serial adapters

1-port serial
Manufacturer: ST Labs

4-port serial
Manufacturer: Aten
Model: UC2324
Driver for Windows XP, Windows, Windows Vista, Vista (32 bit), Windows 7, Windows 8, Windows 8.1 -- V2.0.7.0 -- 2014-09-11 -- uc2322_2324_4852_4854_windows_v2.0.7.0.zip

SURVEYS 2008 - 2019

Single hydrophone

We have been using:

ITC mod ITC-8073
Teledyne mod. AQ-18 --- Source: http://www.benthos.com/pdf/HydrophoneBrochure.pdf

Splicing of hydrophone cable

Hydrophones are normally ordered unterminated. In order to splice the hydrophone cable to a suitable underwater pigtail cable (which is delivered with one connector; the other side is open) an inline cable splicing kit must be used:

Supplier of 3M liquid epoxy splices for water tight joints, mod 82A
3M mod. 82-A Cable Splice Kit data sheet
3M Scotchcast™ Resin Kits 92-NBA 0 up to 92-NBA 7 Inline Joint Kit Series with Resin 40G PDF (also local copy)
- El.nr.: 1165980 -- Scotchcast 92-NBA0 -- Straight casting form, 4x1.5-4mm²
- El.nr.: 1165981 -- Scotchcast 92-NBA1 -- Straight casting form, 4x1.5-10mm²
- El.nr.: 1165982 -- Scotchcast 92-NBA2 -- Straight casting form, 4x6-16mm²

Norwegian suppliers:

We have ordered 3M Splice Kit with El.no. 1165981
Datasheet 3M Splice Kit
3M Norway
Onninen
Otra
Ahlsell
NOTE: RS-NO is not distributor for 3M Splicing Kits

Interface between hydrophone AQ-18 / 6 ch streamer and GEODE recording system

Click to see large version:

Interface between Teledyne AQ-18 Hydrophone / 6 channel mini-streamer and Geode Recording system - click to see large version.

Recommended AQ-18 decoupling and wiring.

The recommended decoupling is done in the interface box shown below. The interface is also furnished with a DC/DC-converter in order to provide a clean 12 Vdc power source for the hydrophone.

Teledyne hydrophone AQ-18 interface box (click to enlarge).

6 channel mini-streamer terminals, Geode recording cable (click to enlarge).

Mini-streamer, 6 channels

Mini-streamer layout.

Mfr: SigFrance
Channels: 6
Model: SIG 16.6x4.46
S/N: 08044
Date: 04/2008
Hydrophone elements:
- Sensitivity: -90 dB re 1 V/uBar, +/- 1 dB
- Frequency response: Flat +/- 1 dB over the frequency range 10 to 1000 Hz
- Max operating depth: 80 m
- Capacitance: 18.0 +/- 1.0 nF @ 20 deg C and 1 kHz
Active section:
- Length: 46 m
- Diameter: Inside Ø=25 mm, outside Ø=30.5 mm
- Density: 1.05
- Oil: 880
- Number of channels: 6
- Number of hydrophones per channel: 4
Leadin cable:
- Length: 75 m
- Breaking strength: 500 Kg
Preamplifier:
- Number of channels: 6
- Gain: 32 dB (=40x)
- Bandwidth: 2 - 3000 Hz
- Maximum voltage output: 12 V p-p
- Current consumption: < 2 mA

Seismic source

Airgun, Bolt xx cu inch
Airgun Control Uni (GUNCO): UiB "Mini-Gunco"
Software for triggering of GUNCO and Recording equiment: gunco_v03.py.
This is a very simple Python program. It can be modified to provide distance shooting - it's on the To-Do list ...
- First version: ~~gunco.py~~.
- Second version: ~~gunco_v02.py~~.
Description of Mini-GUNCO, incl. software for trigger control

Recording

Geometrics Geode

Geometrics GEODE
Software can be downloaded from ftp://geom.geometrics.com/pub/seismic/Geode-NZ/
Select latest version (as of April 2010: Ver. 9.30).

GPS for time- and position stamping of data

GPS: Garmin GPS 35-HVS
GPS has been configured to only output GPGGA NMEA telegram. Link to configuration program and User Manual. The GEODE has a small quirk in that you cannot specify the NMEA telegram to record alongside seismic data. So to ensure consistency in time/positional logging the attached GPS should output only one type of NMEA telegram.

Configuration for use with UBS based GPS

If a USB based GPS should be used, there is a problem as the Geode software only accepts serial port in the Keep('COM1') to Keep('COM4') range, see screenshot below.

The USB based GPS will normally be assigned to a COM number in a higher range. So a remapping of COM port assignment need to be done.

Geode software serial setup menu.

Default COM port assignment and NMEA telegram output from ordinary USB/GPS shown below.

Data from USB/GPS, default selection of telegrams.

Re-assigning COM port to fall within the 1-4 range is accomplished from Control Panel -> Hardware -> Comport -> (properties of USB/GPS port)

In advanced settings, you can force comport setting to an available number within the 1-4 range that Geode software accepts.

Backup recording system

Ref. notes on this page.