INSTALLING THE ACTIVE SURFACE
The installation phase foresees firstly the dismount of the old panels, then the mounting of the actuators and their alignment, then the mounting of the new panels and the alignment of the all surface on a parabolic shape at a fixed elevation. Finally the aligned surface will be read at different elevations to verify the residuals of the best fitted parabola. The installation was a collaboration among the Noto staff, the engineers of the Medicina station, NOVANT firm of Guidonia (Roma, Italy), COSPAL Composites Srl of Ambivere (Bergamo, Italy).
Mounting the actuators
| The antenna without old panels. |
Actuator. | |
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| Actuators mounted. | |
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Aligning the actuators
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Actuators alignment tool.
It is made by a reference plane over which two levels and an hollow corner cube are mounted. The level guides the tilting whereas the corner cube, together with a total station theodolite, the translations. With respect to the ideal shape the translations allow an alignment within 1mm, the tilting within 20 arcmin. |
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Total station theodolite.
It measures angles and distance of the target. |
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Mounting the panels
| A panel corner on an actuator. | Panels mounted. |
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| Four corners of the panels mounted on an actuator. |  |
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 | Four corners of the panels mounted on an actuator |
Aligning panels
| View of the target to be sighted by the theodolite.
The alignment is made in two phases: the upper right corner of each panel is put on the ideal parabolic shape by using the theodolite and the bolt underneath. This corner will be the reference point with respect to which the corners of the near panels will be put on the same plane. |
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| View of the tool used to align the near three corners on the same plane of the reference corner.
It has four digital micrometers and two electronic levelmeters. The plane mirror is used in order to correctly orients the tool and the electronics allows to remotely read the micrometers and levelmeters. The four corners are on the same plane within 50 microns. | |
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Reading at different elevations the aligned surface
| Targets on the four corners panels. | Reading the surface is made during night in order to avoid thermal effects on the structure. |
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