Geospace Technologies GCX3 Users Manual

Geospace Combined Recorder (GCX)

USER MANUAL

7007 Pinemont

Houston, TX 77040 USA

CAUTION: Any changes or modifications to this device not explicitly approved by the manufacturer could void your authority to operate this
equipment.

FCC
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful

interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

The device has been found to be compliant to the requirements set forth in CFR 47 Sections 2.1091 and Industry Canada RSS-102 for an
uncontrolled environment. It is expected that this equipment will generally be operated with a separation distance of at least 20centimeters
between the transmitter’s radiating structure and the body of the user or nearby persons.

Industry Canada
(English)
This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device
may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the
device.

(French)
Le présent appareil est conforme aux CNR d’Industrie Canada applicables aux appareils radio exempts de licence. L’exploitation est autorisée
aux deux conditions suivantes : (1) l’appareil ne doit pas produire de brouillage, et (2) l’utilisateur de l’appareil doit accepter tout brouillage
radioélectrique subi, même si le brouillage est susceptible d’en compromettre le fonctionnement.

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GCX User Manual

GCX MODULE

Deployment

The GCX should be deployed with the metal plate down. This provides sufficient earth grounding and
maximum cooling of the unit as well as providing the GPS receiver in the top to the unit with an ideal
“view” of the satellite constellation. The grounding spike should be fastened to the unit prior to
deployment to provide maximum earth coupling. The unit should be transported on its side in order to put
the unit into standby mode and minimize battery consumption prior to use. Once the unit is ready to be
deployed it should be flipped spike down and the GCX will immediately begin power on self-test.

The GCX will test all of its internal circuits followed immediately by an impedance test of the seismic
sensors. The LED that can be seen from the top of the GCX will flash codes to indicate the GCX’s
condition. The GCX will enable the Global Positioning System (GPD) receiver and begin to flash the
code that indicates that it is searching for satellites. Within a few seconds the GPS receiver will have
sufficient satellite information to obtain a 3 dimensional fix. The flash code will change to indicate this
condition and the GSR will now begin to acquire seismic data if it has been programmed to begin
recording immediately. See Programming below. After several minutes the internal GSR clock will be
sufficiently disciplined and the GPS receiver will be turned off. The flash code will again change to
indicate this state. See the flash codes below.

Radio Status Monitoring

A GSR may be connected to a laptop computer and used as a hub to monitor the status of any GSRs
within a 50m to 100m radius via a high frequency radio link. In this mode the laptop/hub monitors and
logs status information from all of the GSRs that it communicates with. The laptop stores the GPS
location, acquisition status, temperature, battery status and the nonvolatile memory status of each GSR.
By moving the hub throughout the seismic spread all of the GSRs in the survey may be monitored and
logged. This logging may take place during acquisition of seismic data with no adverse effect on the data
quality.

GCX User Manual

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Flash Codes

GSR Start-up Error Codes

Critical GSR Error: LED flashes repeatedly on solid for 1 second followed by off for one second.
Critical Seis Input 1 Error: LED on solid for 1 second followed by 1 short pulse.
Critical Seis Input 2 Error: LED on solid for 1 second followed by 2 short pulses.
Critical Seis Input 3 Error: LED on solid for 1 second followed by 3 short pulses.
Critical Seis Input 4 Error: LED on solid for 1 second followed by 4 short pulses.
Critical Battery Error: LED on solid for 1 second followed by 5 short pulses.
Non-Volatile Memory Error: LED on solid for 1 second followed by 6 short pulses.
Non-Volatile Memory Full: LED on solid for 1 second followed by 7 short pulses.

GSR Run Time Codes

GPS on but no GPS fix: One LED flash per second.
GPS on with GPS fix: Two quick flashes once per second.
Recording with GPS off: One quick flash each 8 seconds.
Sleeping: Two quick flashes each 10 seconds.
Running geophone tests: LED flashes on for 10 ms 5 times per second.

Downloading

The GSR non-volatile memory may be read and cleared by removing the battery connection and
inserting the unit into one of the outlets in the GeoReaper. See the GeoReaper User Manual for
further instruction.

Programming

The GSR recording parameters such as sample rate, pre-amp gain, record mode, and testing, are
programmed and stored in non-volatile memory in the GSR by the GeoReaper. See the
GeoReaper User Manual for further instruction.

GCX User Manual

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