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21
time in the field notes
Figure 18. Установка TRIUMPH-1M
To start survey TRIUMPH-1M should be set up on a
tripod or in a pole. TRIUMPH-1M has 5/8” mount to
connect to monopod, to tripod or to surveying pole.
Collecting data
See the remaining sections in this chapter for more
information on collecting data.
• Turn on the receiver.
• Once the receiver has locked on to eight or more
satellites the SAT light will green.
• A red color of POS LED indicates that the receiver
has not solved a position. Four or more satellites
provide optimal positioning.
• Once the red POS LED is green, the receiver has
a position and surveying can begin; wait for green
light before beginning data collection. This en-
sures that the receiver has the correct date and
time, and is locked on to enough satellites to en-
sure good quality data.
• The process of locking on to satellites normally
takes less than one minute. In a new area, under
heavy tree canopy, or after resetting the receiver, it
may take several minutes.
• To begin collecting data, press and hold the Re-
cord button (for more than one second and less
than five seconds).
• Release the Record button when the REC (record-
ing) LED turns green. This indicates that a file has
opened and data collection has started. The REC
LED blinks each time data is saved to the internal
memory.
When finished, press and hold the Record button
until the REC LED light goes out.
To turn off the receiver, press and hold the power
key until all lights go out, then release.
Static Surveying for Base Stations
Static surveying is the classic survey method, well
suited for all kinds of baselines (short, medium, long).
At least two receiver antennas, plumbed over survey
marks, simultaneously collect raw data at each end of
a baseline during a certain period of time. These two
receivers track four or more common satellites, have
a common data logging rate (5–30 seconds), and the
same elevation mask angles. The length of the obser-
vation sessions can vary from a few minutes to sev-
eral hours. The optimal observation session length
depends on the surveyor’s experience as well as the
following factors:
• The length of the baseline measured
• The number of satellites in view
• The satellite geometry (DOP)
• The antenna’s location
• The ionospheric activity level
• The types of receivers used
• The accuracy requirements
• The necessity of resolving carrier phase ambigu-
ities
Generally, single-frequency receivers are used for
baselines whose lengths do not exceed 15 kilometers
(9.32 miles). For baselines of 15 kilometers or greater,
use dual-frequency receivers.
Dual-frequency receivers have two major benefits.
First, dual frequency receivers can estimate and re-
move almost all ionospheric effect from the code and
carrier phase measurements, providing much greater
accuracy than single-frequency receivers over long
baselines or during ionospheric storms. Secondly,
dual-frequency receivers need far less observation
time to reach the desired accuracy requirement.
After the survey completes, data the receivers col-
lect can be downloaded onto a computer and pro-
cessed using post-processing software (for example,
JAVAD GNSS Justin).
Kinematic (Stop & Go) Surveying for
Rover Stations
In a kinematic, stop and go survey, the stationary
receiver (Base station) is set up at a known point such
as a survey monument, or an unknown point. The re-
ceiver continually tracks satellites and logs raw data
