Leica Geosystems TPS1100 Professional Series - Reference Manual - Manual (Page 88)

88
TPS1100 - Appl. Prog. Ref. Manual 2.2.0en Hidden Point
Application notes
To Test / Prove the Hidden Point
program
Setup and orient the instrument in an
open area. Check the configuration
to be sure the hidden point rod and
prisms are properly defined. Position
the tip of the hidden point rod on a
mark that is directly visible from the
instrument location.
Start the hidden point program and,
making sure the hidden point rod
does not move between
measurements, measure the prisms
on the hidden point rod.
Store the coordinates of the "hidden
point" on the Memory Card. Start the
Setting Out program, make sure the
configuration allows for 3D
positioning, then select the previously
stored "hidden point" for setting out.
Motorized instruments will drive
directly to the point, which will then
be behind the crosshairs of the
telescope.
Manually turn non-motorized
instruments until the
∆
Hz and
∆
V
both equal zero. The "hidden point"
will be behind the crosshairs of the
telescope.
Uses for the Hidden Point program
The hidden point program may be
used to obtain accurate three
dimensional coordinates for a point
that is currently blocked from direct
measurement by an obstruction
between the point and the
instrument.
Typical uses are:
• Determination of flow line locations
and elevations in manholes,
without measuring from the rim of
the manhole to the flow line and
estimating corrections for non-
verticality of the measuring tape
and eccentricity from the
measurement on the rim to the
horizontal location of the flow line;
• Determination of recesses in
building corners for detailed
surveys, without estimating right
angle offsets, with or without
taping of the dimensions;
• Measurements behind overhangs,
buttresses and columns for
quantity determinations in
underground construction or
mining, without estimating right
angle offsets, with or without
taping of the dimensions;
• Measurements of industrial
process piping or other equipment
in close quarters;
• Detailed architectural surveys for
remodeling or cultural preservation
or restoration work;
• Any place where accurate
measurements would require
many more instrument setups in
order to achieve line of sight from
the instrument to the points being
measured.