LDI Intellectual Property.
Not for secondary distribution or replication, in part or entirety.
DIGISONDE-4D
SYSTEM MANUAL
VERSION 1.2.11
2-4 SECTION 2 - INSTALLATION, SETTING UP AND FIELD VALIDATION
PRE-INSTALLATION CHECK
2:5. Prior to installation, place the sounder on a desk or table preferably in the position where it will be
permanently operated. Allow at least 40 cm clearance between the rear of the case and any vertical surface
to provide access to the rear I/O panel.
2:6. Remove the front and rear covers and inspect all external fittings for damage. Replace the rear cover
before making any cable connections. In turn, release each chassis from the case, remove the chassis cover
and inspect for shipping damage. Check for and make good any loose connectors and unseated cards.
EXTERNAL CONNECTIONS
ANTENNA INSTALLATION
General Requirements
Vegetation/Conductive Obstructions
2:7. The antenna field usually consists of two transmit antennas crossed on a single mast (TCI 656 designed
by LDI), and four receive antenna stations. The installation site requires to be cleared and kept cleared of all
vegetation within a 0.5 m radius from the antenna and isolated from conductive obstructions by at least a ra-
tio of 10:1 (separation distance : longest dimensions of the obstruction).
2:8. The transmit antenna mast must not be closer than 30 m to the closest receive antenna station, and
when using RG-213 cable, desirably it should not be more than 120 m from the sounder. If the transmit an-
tenna is to be installed at a distance greater than 300 m from the sounder use of a Heliax type cable is sug-
gested. If one is considering locating the transmit antenna at a distance greater than 500 m from the sounder,
it is suggested to consult with LDI.
2:9. Any of the receive antennas should be at least 16 meters, preferably a little more, from any part of the
transmit antenna.
2:10. Placement of receive antennas near fencing, walls, buildings, or other structures which contain horizon-
tal conductors are of special concern. Horizontal conductors located near receive antenna could short out
the electric field component of signals received by the receive loops parallel to those conductors. Buildings
and other structures which contain horizontal conductors that are 15 m or less from the center of a receive
antenna should be evaluated on a case by case basis. If a receive antenna is to be placed near metallic fenc-
ing or walls containing horizontal conductors (such as rebar) please use the following general recommenda-
tions:
2:11. The center of the receive antenna should be no less than 7 m minimum distance from a metallic fence
or wall 1 m in height.
2:12. The center of the receive antenna should be no less than 10 m minimum distance from a metallic fence
or wall 1.5 m in height.
2:13. The center of the receive antenna should be no less than 15 m minimum distance from a metallic fence
or wall 2.5 m in height or greater.
2:14. Trees are probably not a serious issue, but they certainly should not overhang the antennas. Ideally,
looking upward from any antenna there should be a 45 degree (measured from zenith) cone clear of any ob-
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General