User's Manual

IDS Ingegneria Dei Sistemi S.p.A. N°doc: MN/2009/070 - Rev. 1.1

IBIS-L v.02.00 - User manual

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Fig. 3.16 – Back of linear scanner

Next to these connectors on the panel, there are three green LEDs which, when lighted,

indicate that the power supply is connected to the trolley positioning sensors, the step by

step motor and the IBIS sensor.

The linear scanner is used to move the sensor in along the track orthogonally to the

irradiating direction (antenna axis). The trolley is moved in steps for a total effective

length of 2 m. There is a waiting period between two successive steps equal to the

functioning time of the IBIS sensor.

For long-term monitoring the instrument must be positioned on a stable solid horizontal

base with minimum dimensions of 2000mm x 800mm x 200mm (length, width and

thickness), i.e. a concrete base. These measurements have been established to guarantee

the necessary robustness and permit the inclination of the linear scanner as required.

The system for fixing the linear scanner to the ground has been designed to allow it to be

accurately repositioned quickly and easily. In case of slow movements this means the

instrument can be used at intervals, over a period of several months, without having to

leave it positioned outdoors for the entire period. It is important to underline that the

expected movement between two discontinuous acquisitions has to be smaller than λ/4,

that is 4.3mm for Ku band system and 7.14mm for X band system, to not encounter in

displacement measurement ambiguity.

The basic fixture system consists of:

• Three support points (Fig. 3.17) positioned on three studs that fix the plane the

module will slide over.

• A reference sphere positioned under the track and inserted into a specific housing,

and which, when joined to the plane, forms an axis of rotation passing through the

centre of the sphere and normal to the plane.

• A positioning fork providing a buffer to block rotation with respect to the rotation

axis centred on the sphere.

• A screw opposite the buffer to block the module at the buffer point.

Back panel

Mobile

connectors