33
TS Functions
33.1
EDM
E
lectronic
D
istance
M
easurement
EDM
is the function used for distance meas-
urements.
There are different modes the instrument can work in. Refer to "22.1.1 Meas-
33.2
Prism Search Methods
33.2.1
Automatic aiming
Automatic aiming is the function which recognises and measures the position
of a prism using a CCD array. A laser beam is transmitted and the built-in CCD
array receives the reflected beam. The position of the reflected spot is compu-
ted regarding the centre of the CCD. These automatic aiming offsets are used
to correct the horizontal and vertical angles. The automatic aiming offsets are
also used to control the motors which turn the instrument to centre the cross-
hairs to the prism. In order to minimise the time for measuring, the crosshairs
are not moved to the exact centre of the prism. The automatic aiming offset
can be up to 500 cc depending on selected
Measure distance
. The automatic
aiming function measures the offsets between the crosshairs and prism centre
and corrects the horizontal and vertical angles accordingly. Therefore the hori-
zontal and vertical angles are measured to the prism-centre, even if the cross-
hairs are not aimed precisely at the centre of the prism.
Motorised instruments can be equipped with automatic aiming. For
Aim at tar-
get:
Automatic
the instrument can find a static prism and measure a distance
once
Measure
or
Distance
is pressed. The instrument does not follow a mov-
ing prism.
The telescope field of view is the region seen when looking through the tele-
scope. The automatic aiming field of view is the region seen by the automatic
aiming. Both are identical on TS instruments.
TS_004
If the prism is in the field of view with
Aim at target:
Automatic
the cross-
hairs are automatically positioned to the prism when, for example
Measure
or
Distance
is pressed. No automatic aiming search is started.
☞
The displayed values are always related to the centre of the prism
after
Measure
or
Distance
is pressed. For
Measure
, these values
are displayed only shortly after the key press.
Description
Description
Field of view
Automatic aiming
measurement
TS Functions
391