The Data Logging pages are used to manage the logging of
GPS observation data to internal memory. These pages are
used to manage Sessions,
enable or disable the
AutoDelete and
Power Saving modes,
and view, download, or delete
logged data files.
The Data Logging Status page provides a global summary of the state
of the data logging system. All currently defined Sessions are listed
in the Session Status Table, which lists
which Sessions are currently logging, and can be used to enable or
disable specific Sessions. Also shown is the status of the
AutoDelete system and the
Power Saving Mode. Links are
provided to edit these controls and create or edit Sessions.
Sessions
A Session is a process that logs data to one or more files.
Each Session is defined with various controls that specify the type of
data to be logged, the schedule for that logging, and the naming
convention to be used for saving the data to files.
A new Session is created from the Data Logging Status page by clicking
on Create a New Session. An existing Session may be modified by
clicking the Session's Name in the Session
Status Table or by selecting Edit Sessions. Any number of
Sessions may be defined, and multiple Sessions may be active at the same
time. The following parameters are defined when creating or editing a
Session.
-
Name - Each Session has a name consisting of up to 10
characters. This name appears in the Session status table and is used
to distinguish between multiple Sessions.
-
Enable - Each Session can be either enabled or disabled.
An enabled Session will perform data logging according to its schedule
and other controls. A disabled Session is prevented from logging
any data, regardless of its schedule. Sessions are enabled by default
at creation time. This control can be changed at any time, either
by editing the Session, or by clicking the Enable checkbox on the
Session Status Table.
-
Schedule - Sessions operate in one of four scheduling modes.
-
Manual Sessions are triggered to start by the user and then run
for a specified duration in minutes. The Session starts when it is
first enabled and stops when the duration time has elapsed. The same
manual Session can be restarted by re-enabling it.
-
Once Only Sessions start at a specific date and time and log
for the specified duration. For example, a Once Only Session could be
created that would start on 4-July-2010 at 14:30 UTC and log for two
hours. This would create a single data file. Note that the date and
time are specified in UTC coordinates and NOT in local time.
-
Daily Sessions start at the same time each day and run for the
specified duration. They create a new data file every 24 hours.
For example, a Daily Session could be created that would log four
hours of data every day starting at 09:00 UTC. This would create
a new data file every day. Note that daily sessions have a maximum
duration of 1439 minutes. To create 24 hour sessions on a daily basis,
use the Continuous Logging mode.
-
Continuous Logging Sessions store data continuously, breaking
the data into multiple files of the specified duration. For example,
a Continuous Logging Session could be created that logged data into
4-hour files, creating 6 of those per day, until logging memory was
exhausted.
-
Data Format - This specifies the format of data that will be
logged and options appropriate to the format.
-
T00 Sessions log data in Trimble's compressed binary format.
- The Measurement Interval defines the epoch interval for GPS code
and carrier phase logging.
- The Position Rate specifies the interval for GPS position
logging.
- Check Smooth Code Phase for carrier smoothed code
observations.
- Check Smooth Carrier Phase to log filtered carrier phase
observations.
Not allowed when Measurement Interval is 0.1, 0.2 or 0.5
seconds.
-
BINEX Sessions log data in UNAVCO's Binary Exchange format.
- The Measurement Interval defines the epoch interval for GPS
code and carrier phase logging. Several options are available for
measurement logging.
- Carrier Phase measurements can be smoothed if desired.
Not allowed when Measurement Interval is 0.1, 0.2 or 0.5
seconds.
- Measurements can be Binex encoded as record types 0x7f-02
or 0x7f-03 (or both).
- Types 0x7f-03 can optionally include Doppler measurements.
- Types 0x7f-03 can optionally include cycle slip counters.
- Types 0x7f-03 can optionally include Clock Offset information
with each measurement record, or only when a clock
offset adjustment is made.
- A system status record (type 0x7d-00) can be saved at specified
intervals. This contains the NetRS internal temperature and
readings of the power source voltages.
- Meta data records can be saved at specified intervals,
containing a choice of Site Description, Station Identifier
string, Receiver Type, Rinex Receiver Number, the NetRS firmware
version, the Antenna position in ECEF-XYZ, the antenna offset,
and a Rinex style antenna serial number.
-
File Naming - Filenames always include the NetRS System Name and
a string that encodes the time at which the logging Session was started.
A Session Identifer character is appended to that, along with a three
character file extension (.T00 or .BNX). When this is all put together,
filenames look like:
SystemNameYYYYMMDDHHmmS.T00
The Session Identifier is a single character that can be used to
distinguish between files that are created by different Sessions. In
general, a unique character should be chosen for each Session. If two
Sessions are started which attempt to log simultaneously to the same
file name, one of the Sessions will be unable to log data.
-
Directory Options - By default, files are logged in a directory
structure organized by the year and month with a
YYYYMM/
naming format.
- Checking Create Per-Day subdirectories will log all data
files for each day in separate subdirectory. This will create
directories of the form
YYYYMM/DD/
.
- Checking the Create Per-SessionId subdirectories will
create an addition subdirectory containing all files with the same
Session Identifier character, as in
YYYYMM/DD/S
(where 'S' is the Session Identifier.
Note that there is no design imposed limit on the number of Sessions
that may be created, but it is possible to exceed system performance
limits by creating a large number of high data rate Sessions that are
active at the same time.
A Session may be deleted by editing the existing Session and selecting
the Delete button at the bottom of the page.
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Session Status Table
The Session Status Table on the Data Logging Status page shows the
current state of all Sessions defined on the system, and allows
individual Sessions to be enabled or disabled. This table shows
the following parameters.
-
Session Name - The name defined when the Session was created.
-
Schedule - Shows the type of schedule used for the Session.
-
Duration - Session or file duration in minutes.
-
Status - Each Session is in one of several states:
- Disabled
- Pending - waiting for its scheduled start time.
- Logging - actively logging data to an indicated file.
- Completed - finished and will not start again.
-
Enable - This checkbox shows whether the Session is currently
enabled to operate. Entering a check in this control will activate a
Session for immediate or future logging, Clearing the check will
immediately disable a Session and terminate any currently active
logging by that Session.
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