Sercel LAUR Geophysical Transceiver User Manual laur user

Sercel Inc Geophysical Transceiver laur user

Contents

User Manual 1

User manual
November 24, 2004 1
User manual
Introduction
The LAUR (Line acquisition radio
unit) is used as an element of an LRU
relay cell. It can be inserted anywhere
in a seismic line to collect the data
from FDUs on either side of it, and
relay the data to the associated LRU.
Built in the LAUR is a full
performance LAUL, optimizing the
deployment of field hardware.
Operating in a relatively low radio frequency band (215 MHz to
250 MHz), it can be used in difficult areas. The user can choose
between various configurations, depending on the required data rate and
on the expected transmission range.
Using a handheld terminal as a Field Deployment Aid, the radio link can
be set up adequately prior to connecting the LAUR to the seismic
network. The parameter settings can also be changed through the HCI
workstation.
NOTE: The available frequency band depends on the regional settings
chosen by the user when installing software on the HCI workstation and
on the handheld terminal. For compliance with Canadian and US
communications regulations, the frequency band is limited to
respectively:
• Canada: 217 to 218 MHz and 219 to 220 MHz.
• USA: 216 to 217 MHz and 218 to 219 MHz.
Figure 1 LAUR
User manual
2November 24, 2004
Typical setup
CAUTION
If you wish to test a radio relay cell through a wireline link between the
coaxial connectors of the LRU and the LAUR, use a 60 dB (minimum),
20 W attenuator.
Figure 2 Test setup
CAUTION
Antenna height is limited to 6.1 metre near airports.
Do not raise any antenna near electric power distribution lines!
WARNING
LAUR antennas should be kept at least 10 m away from any FDU.
20 W
60 dB min.
12 V
12 V
Attenuator
LRU
LAUR
User manual
November 24, 2004 3
Basic radio cell
Below is a typical example of setup along with the associated
specifications in terms of covered range and transmission capacity.
Figure 3
Typical performance (Ground-Wave propagation above flat
terrain):
- Short Range: 2 km to 3 km, 60 Ch @ 2ms , Real time, using
2.5-m high LRU antenna.
- Medium Range: 3 km to 8 km, 60 Ch @ 2ms, Real time, using
8-m portable LRU antenna mast.
- Long Range: 8 km to 16 km, 60 Ch @ 2ms, Real time, using
30-m LRU antenna mast.
See CAUTION on page 2.
LRU
12 V
Unit
Transverse
to Central
Line or
LAUR
12 V
Coax downlead
1
See
7-element
Yagi antenna
Battery
(30 channels max on either side)
below
1
User manual
4November 24, 2004
Specifications
LAUR
• Functions
- Management of FDUs and wireline data acquisition;
- Radio data transmission to LRU base station with error recovery
and temporary storage;
- 48V wireline power supply.
• Memory
- 32 MB local buffer for non-real time transmission mode;
- 32 MB non-volatile memory for local storage of
acquiredchannels.
• Ports: Ethernet 10/100 Mbps compatible.
• RF Frequencies
- USA: limited to 216 to 217 MHz and 218 to 219 MHz;
- Canada: limited to 217 MHz to 220 MHz, restricted to remote
area.
- Other countries: compliance with local regulations.
- Overall capability: 215 MHz to 250 MHz.
• RF Output Power
- RF power management;
- 1W to 6 W, nominal.
• RF Output Impedance: 50 Ω.
• Emission Designators: 200KD1D and 800KD1D.
• Maximum number of FDUs per LAUR: 60 with up to 110 m interval.
• Maximum number of FDUs between LAURs (wireline): 30 with up
to 110 m interval.
User manual
November 24, 2004 5
•Power
- Operating Power Voltage: 10.5 to 15 VDC, 2 battery connectors
(allowing uninterrupted operation during battery replacement).
- Power Consumption:
• Physical specifications
- Material: Aluminium.
- Size: 380x380x170 mm (15x15x7 in.).
- Weight: 12.250 Kg.
• Environmental specifications
- Operating Temperature: -40° to +70°C.
- Storage Temperature: -40° to +70°C.
- Water Depth: 1 m, operating.
User manual
6November 24, 2004
OWFD1.5 antenna
• Electrical specifications
- Single band, 215 to 250 MHz, no tuning required.
- Impedance: 50 Ω.
- VSWR: < 1.5.
- Gain: 0 dBd, tilt 0°.
- Polarization: vertical.
- Pattern: omnidirectional, ripple < 1dB.
- No ground plane required, apart from LAUR housing
(380x380x150, aluminium, lying flat on the ground).
- Static electricity dissipation to ground.
- Connection: N-type connector, male, modified.
- Max input power: 40 W.
• Physical specifications
- Operating temperature: -40 to + 70°C.
- Height: 1.68 m (66 inches).
- Sealing: IP 66 standard (antenna connected).
- Salt spray resistant.
- Withstands 80 km/hr wind.

Navigation menu