14
Optimizing Geo-Referenced
Measurements
Achieving optimal results of the geo
-
referencing feature depends
on several factors including how long the meter has remained ac-
tive, atmospheric conditions for the day, which satellite systems
are in range and obstacles that may block the reception of the sat-
ellite signals. The meter accesses 3
-
4 satellite systems, each with
different levels of accuracy available to the general public.
Galileo: within 1 meter of target
GLONASS: within 2.8
-
10 meters of target
GPS: within 3.5
-
7.5 meters of target
QZSS (where available): within 1 meter of target
Additionally, systems such as SBAS, MSAS and others are used
along with the meter
’
s own internal satellite mapping data to im-
prove the accuracy further.
Creating the internal satellite maps
The meter relies on internal satellite maps to improve accuracy.
These maps are built by the meter during the first three days of
consistent use. The meter will track available satellites and hone
in on the location of use by referencing the internal maps along
with satellites in view. Typically, after the first use, the position
accuracy may appear low as the satellite maps are synchronized
with the area in which the meter is being used. After the third use,
the TDR will have a complete satellite map of the use area and the
speed and accuracy of the location referencing will be at its best.
Internal maps will re
-
synchronize if the meter has been out of use
for a season or taken out of its usual use areas. This process may
result in lower accuracy until the synchronization has completed.