Sercel LAUR Geophysical Transceiver User Manual laur user

Sercel Inc Geophysical Transceiver laur user

Contents

User Manual 1

User manualNovember 24, 2004 1User manualIntroductionThe 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 manual2November 24, 2004Typical setupCAUTIONIf 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 setupCAUTIONAntenna height is limited to 6.1 metre near airports.Do not raise any antenna near electric power distribution lines!WARNINGLAUR antennas should be kept at least 10 m away from any FDU.20 W60 dB min.12 V12 VAttenuatorLRULAUR
User manualNovember 24, 2004 3Basic radio cellBelow 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.LRU12 VUnitTransverseto CentralLine orLAUR12 VCoax downlead1See7-elementYagi antennaBattery(30 channels max on either side)below1
User manual4November 24, 2004SpecificationsLAUR• 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 manualNovember 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 manual6November 24, 2004OWFD1.5 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.

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