Javad DELTA-3, Руководство пользователя

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15
Real Time Kinematic Surveying
With RTK surveying, as with kinematic surveying
described above, one receiver serves as the reference
station and conducts observations with its antenna af-
fixed to a stationary tripod or some other device. The
other receiver functions as a rover and conducts obser-
vations (using an antenna) affixed to a mobile pole and
moved to observation points.
Unlike post-processed kinematic surveys, RTK sur-
veys utilize a communications link between the Base
and Rover. Using a radio modem link, the Base receiv-
er transmits its measurement and location data to the
Rover receiver. The Rover, based on the transmitted
data and its own observation data, immediately con-
ducts a baseline analysis and outputs the results.
Usually, the receiver will start to output the coordi-
nates of the antenna’s phase center along with the solu-
tion type within 10–30 seconds. However, UHF radios
and GSM phones may take as long as 60 seconds to
synchronize. The geodetic coordinates displayed on the
Location tab are always computed in WGS84 and have
four solution types.
• Standalone – where the receiver computes 3D co-
ordinates in autonomous mode without using differ-
ential corrections.
• Code differential – where the Rover receiver com-
putes the current relative coordinate in differential
mode using only pseudo ranges.
• RTK float – where the Rover receiver computes
the current relative coordinates in differential mode
using both pseudo ranges and phases; however, with
a float solution, the phase ambiguity is not a fixed
integer number and the “float” estimate is used in -
stead.
• RTK fixed – where the Rover receiver computes
current relative coordinates, with ambiguity fixing,
in differential mode. The LQ field reflects the status
of the received differential messages and contains
the following information:
• Data link quality in percentage
• Time (in seconds) elapsed since the last re-
ceived message
• Total number of received correct messages (de-
pendent on the message type received)
• Total number of received corrupt messages (de-
pendent on the message type received)
• If the receiver is not (for some reason) receiv-
ing differential corrections, or if none of the ports
has been configured to receive differential correc -
tions, the LQ field will either be empty or it will
look like this: 100%(999,0000,0000).
Receiver and File Maintenance
If post-processing the data after completing a mea-
suring, the data in the receiver’s memory will need to
be downloaded to a computer. Downloading and delet-
ing files will also prepare the receiver’s memory for the
next measuring. Occasionally, the receiver’s NVRAM
may need to be cleared to eliminate communication
or tracking problems. As project expectations expand,
the receiver’s OAF may need to be updated to provide
expanded operation and functionality. The receiver
requires firmware to properly operate and provide ap -
propriate functionality. As JAVAD GNSS releases firm -
ware updates, loading these updates into the receiver
will ensure that the receiver operates at its full potential.
Deleting Files and Downloading Files to a
Computer
When your measuring finishes, you can down -
load your measuring files to a computer for storage,
post-processing, or backup. Also, the DELTA memory
holds a finite amount of files and information, so down -
loading the files to a computer ensures that no files are
lost. You should download files as soon as possible af -
ter collecting data at the jobsite. NetView provides a
File Manager to download files to your computer and
delete files from the receiver DELTA.
Connect your receiver and computer. Start NetView.
Establish connection between NetView and receiver.
Click File on the left panel. On the right panel appears
the list of files, saved in receiver’s memory. Select the
file(s) to download:
Figure 17. Downloading files
Click the Download button. During the download,
status indicators display each file.