The
Leica Viva imaging
Total Stations are fitted with a 5 Mpixel CMOS sensor, which
with a 21mm lens provides a field of view of 15.5° by
11.7°. The sensor has a 20 Hz refresh rate providing a smooth
visual presentation.
The on-board
camera can be used to record images and relate them to one
or more measured points, and can be used to control the
Instrument. The captured images can be annotated by
the user and the imaging software can also be used to make a
"screen capture" of any screen displayed, which can also be
annotated as required. The annotation functionality
can also be used to sketch to a blank screen providing
maximum versatility in the field. There is no longer
any need for the Surveyor or Engineer to take a notebook or
camera to the field.
Tap - tap the screen to tell the Instrument where
to turn to
Turn - The Instrument turns to the tapped
location
Measure - Press Meas and the Instrument
locks onto the prism with the ATR (Automatic Target
Recognition) and measures
The image can be stored
automatically to every measured point or assigned to any
point in the database.
Capture an image with or
without the cross hairs and add information:
Capture
- record any image displayed by the Instrument
Sketch
- Add information to the screenshot through sketching with
any colour, line style and line width
Link - Link the image to any object of
interest (point, line or area)
The image can be assigned
to any point in the database.
Capture any data displayed
to the screen:
Capture
- Capture a screenshot of any panel in SmartWorx
Sketch
- Add information to the screenshot through sketching
with any colour, line style and line width
Link - Link the image to any object of
interest (point, line or area)
The image can be assigned
to any point in the database.
Image Assisted Surveying greatly enhances the
functionality, ease of use and productivity of the on-board
applications for the
Leica Viva
Instruments. The
animation shows the Instrument running the
Grid Scan application.
The irregular polygon for the area to be measured is defined
by using the Tap and Turn functions on the displayed image.
The Instrument is measuring a regular grid on the defined
plane and the operator has the option to record the image
for each measured point. The application can also
measure all the points where the defined grid meets the
boundary of the area being measured and the displayed image
shows these. Control of the Instrument is through the
full VGA touch screen.
These
features are particular useful when using
Grid Scan to measure
subjects such as stock plies for immediate volume
calculations
One of the major
advantages of
Image Assisted Surveying
is that it combines the previously separate operations of one person
(robotic) surveying and reflectorless measurement. The use of
reflectorless measurement requires an operator at the Instrument to
position the cross hairs on the point of interest, whist the use of
the Instrument in one person mode requires the operator to be at the
detail pole. With Image Assisted Surveying it is now possible
for the operator to be at the detail pole and turn and aim the
Instrument to a point for reflectorless measurement. Consider
the scenario where the operator is at the detail pole some distance
from the Instrument (say 100m) and wishes to measure an inaccessible
point. e.g. the operator is on the left side of the river in
the image and wishes to record the position of the tree. The
operator no longer needs to return to the Instrument to make the
measurement but simply turns the Instrument by tapping on the image
then measures to the point of interest.
History
The
connection between imaging and measurement in the Leica Wild Kern
organisation goes back nine decades. Heinrich Wild created the
Wild P30 at the same time has he created the legendry Wild T2 1"
theodolite. More than half a century later, in the early
1970s, Wild Heerbrugg launched the Wild P32 camera which was mounted
on top of a theodolite, such as a Wild T2 or Wild T1. These
Instruments provided the user with images that could, in today's
terms, be geo -referenced. They had location and orientation
and this information could be used to extract information for
measurement purposes. Data extraction could be by using either
a conventional Photogrammetric procedure or by methods such as
Photographic Intersection.
These cameras used film or glass plates to record the images and
were constructed to have virtually no lens distortion, but modern
digital cameras could be used in the same way with the lens
distortions corrected by computer software.
Some
two decades later, in the 1990s, Leica Geosystems in connection with
Generics, based in Cambridge, England, developed a theodolite with
the conventional telescope replaced by a digital camera.
Control and aiming of this Instrument was via the image displayed to
the screen. The prototype, shown here, was produced, but the
project was not pursued, presumably because of the difficulty of
including a co-axial EDM. However, the potential of
Image Assisted Surveying was
well demonstrated. As with the
Wild P30 and Wild P32,
this device provided an image with a known location and orientation,
which was suitable for data extraction using Photogrammetry or
Photographic Intersection.
Leica Geosystems
have waited for the relevant technologies to mature sufficiently
before launching
Image Assisted Surveying.
Products that are on the "Slope of Enlightenment" or "Plateau of
Productivity" on the
Gartner Hype Cyclecan be relied on and trusted. The wide angle digital
camera with its 5 Mpixel sensor and the full VGA screen provide the
required resolution and precision for
Image Assisted Surveying.
Photogrammetry
and Photographic Intersection
The prime objective
of
Leica Geosystems
introducing imaging with the
Leica Viva Total Stations
is to provide the user with
Image Assisted Surveying to increase productivity
in the field and ease of use of the Instrument. However, there
is clearly the potential to use this functionality for
Photogrammetry and Photographic Intersection.
The internal wide
angle camera is calibrated and the values can be out be output with
the measured data using theFormat File
options available in
Leica Geo Office
(LGO). The Inner Orientation values include the Principal
Point (pixel co-ordinates) and Focal Length and the Exterior
Orientation values are calculated for each captured image. The
Exterior Orientation values include the co-ordinates of the
Projection Centre and the direction of the Principal Ray as
Horizontal and Vertical Angles. Each image therefore has
location and orientation and is available for Photogrammetric
interpretation.
