System accuracy: Several factors can influence the accuracy of the system for determining the location of a prism
• Internal ATR accuracy
• Angular accuracy of the instrument
• Type and centring accuracy of the prism
• Selected EDM measuring programs
• External measuring conditions
Therefore, the overall pointing accuracy of the determined point location can
be lower than the given angular accuracy and the ATR accuracy.
The following paragraphs provide a short overview of these influencing factors
and their possible intensities.
Angular accuracy
The accuracy of angular measurements depends on the instrument type. The
angular accuracy for total stations is typically in the range from 0.5² to 5². The
resulting error depends on the measurement distance.
The table shows possible deviations for typical angular accuracies. 1² and 3²
are examples.
☞ Refer to the data sheet of the respective instrument variant for information about the angular accuracy.
EDM accuracy
The distance measurement accuracy consists of two parts: a fixed value and a
distance-dependent value.
Example: "Single measurements: 1 mm + 1 ppm (1 mm + 1x10-6D)"
The EDM accuracies for prism and reflectorless measurements can differ.
Additionally, the accuracies can differ depending on the used technologies.
☞ Refer to the appropriate data sheet for information about the EDM accuracy.
ATR accuracy
Automatic target aiming accuracies, like those of the ATR, are in general the same as the stated angular accuracy. Therefore these accuracies are also distance-dependent parameters.
External impacts, like heat shimmer, rain (prism surface or telescope lens covered by rain drops), fog, dust, strong background lights, dirty targets, alignment of the targets etc. can have a significant influence on the automated target aiming. In addition, the selected EDM mode affects the ATR performance.
Under good environmental conditions and with a clean, properly aligned target
the accuracy of the automated target aiming is equivalent to the manual target
aiming (presumed valid calibration values).
Type and centring accuracy of the prism
The prism centring accuracy depends mainly on the used prism type, for
example: 
☞ Refer to the white paper "Leica Surveying Reflectors" for information about the different centring accuracies.
More influencing factors
When determining absolute coordinates, the following parameters can also
affect the resulting accuracy:
• Environmental conditions: temperature, air pressure and humidity
• Typical instrument errors, such as horizontal collimation error or index error.
• Proper functioning of laser plummet or optical plummet
• Correct horizontal levelling
• Setup of the target
• Quality of extra equipment, such as tribrach or tripod
Telescope
Compensator
Level
Keyboard display unit
Instrument ports
Pin assignments of the 6 pin LEMO port
Instrument dimensions
Weight
Recording: Data can be recorded onto an USB-C stick or into internal memory. 
AutoHeight plummet
1 Standard deviation (1 sigma) over measurement range
2 Object in shade, sky overcast, Kodak Grey Card (18% reflective), balanced tribrach foot screws
3 Instrument height from tilting axis
☞ Avoid dirt on cover glass.
☞ Avoid line-of-sight obstructions. The full spot needs to be on target.
☞ For best performance use the new Leica tripods. For older tripods, an upgrade of the screw is recommended.
Drives
Motorisation
Power
Internal battery
External battery
Environmental specifications
Reflectors
Electronic Guide Light EGL
Working range: 5m to 150m (15ft to 500ft)
Position accuracy: 5cm at 100m (1.97" at 330ft)
Automatic corrections: The following automatic corrections are made
• Line of sight error
• Tilting axis error
• Earth curvature
• Circle eccentricity
• Compensator index error
• Vertical index error
• Standing axis tilt
• Refraction
• ATR zero point error