User Instructions
and Technical Guide
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displayed. For the project manager, controls to change selected preferences
for this mark only are
provided.
1.5.6.1 Standard Processing Results
Immediately below the label for this section is a pull-down menu giving limited control of scaling for the
reported coordinate uncertainties (Figure 1.70). The default for all projects is one sigma
3
, but a
project’s specifications may differ. Note that this menu is linked to similar menus in the Processing
Results Plots (Section
1.5.7
) and Tables (Section
1.5.8
) sections. Changing the uncertainty scaling here
will change the scaling in these other sections.
Figure 1.70 - Processing results
The remainder of this section is composed of two tables. The first table lists the coordinates from the
designated solution report for this mark. Recall that coordinates in a global reference frame, the ITRF
2000 in the example shown in figure 1.70, are used in the processing and always reported, but an
alternate reference frame or
datum can be selected and, if possible, will be reported. The coordinates
will be listed in a column with the reference frame or datum, and epoch of the coordinates on the first
row acting as a column label. Beneath these, the orthometric height and the geoid model used to
compute this value are given. Similarly, UTM coordinates are always given, but State Plane Coordinate
System (SPCS) coordinates will also be given if the mark is located inside a SPCS zone. Below these, the
U.S. National Grid designation is also given when appropriate.
The second table lists all data files associated with this mark and indicates which are used in the selected
solution along with the values against which the solution quality thresholds are tested. Any of these
values that do not meet these thresholds are highlighted.
3
One sigma, or “1 ” refers to the standard deviation about some mean value.
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Figure 1.72 - Manage a priori coodinates
1.5.6.2 Project Manager’s Processing Results
Like the other sections, the appearance of this section when the mark page is accessed by the project
manager is essentially identical to the display allowed to team members that are not managers. A new
control called
Manage Coordinates appears to the upper-right, in line with the section label (Figure
1.71).
Figure 1.71 - Project manager processing results
1.5.6.2.1
Manage Coordinates
The
Manage Coordinates control permits
the project manager to change the a priori
coordinates and selected preferences
for
this mark only. The standard pop-up
window controls are provided near the top
of the window (Figure 1.72). Below these,
the
a priori Coordinates are given. These
can be presented in one of several
reference frames and epochs in use in the
project. Changing the a priori
coordinates is
not recommended for the following
reasons. The a priori coordinates for all
project marks come from the OPUS solution
for the first data file associated with the
mark and OPUS solutions are known to be
reliable and accurate. However, although
rare, OPUS solutions can be of noticebly
poorer qualtiy especially if GPS satellite visibility is obstructed. For those rare instances when an OPUS
solution is more than 1 meter in error, improving the a priori coordinates can improve the processing
results.
Changing a priori coordinates invalidates any existing processing which includes data from that
mark. so that those processed results will be deleted.
User Instructions and Technical Guide
OPUS Projects
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Below the a priori coordinates are preferences for the
Geoid Model,
SPCS Zone and
SPCS Units.
Usually, the preferences will apply to all marks, but exceptions can occasionally occur. One example is
the SPCS zone. Normally, OP will select the appropriate SPCS zone to use, but, if one is working near the
border between zones, an incorrect zone might be selected, or the project specifications could require
the same SPCS zone be used for all marks. Results using these preferences are derived from the
processing results in the global reference frame, so changing these preferences does
not invalidate
existing processing.
1.5.7 Processing Results Plots
Towards the bottom of the web
page are Processing Results Plots. This section of the web page also
begins with an identifying label. Like all the section labels, it contains a pull-down menu used to
navigate to other project mark web pages (Figure 1.73).
Below this label are controls for the plots. To the far left is a pull-down menu controlling the scaling of
coordinate uncertainties shown in the plots (Figure 1.73). The default for all projects is one sigma. In
addition to being linked to the
Processing Results Tables, this menu is linked to the
Processing Results
(Section 1.5.6) in such a way that changing the uncertainty scaling here will change the scaling for values
given in those sections. To the right are buttons showing the symbols used in the plots for different
classes of results. These buttons toggle display of the corresponding class of results. These are “linked”
to the controls for the
Processing Results Tables (Section 1.5.8) such that toggling a class of
results here
will similarly affect the tables. The symbols used in the plots are:
-Orange shaded areas indicate where results that fail to meet project preferences will appear.
-Gray circles are used for OPUS solution results.
-Blue diamonds are used for session processing solution results.
-Green squares are used for network adjustment results.
Immediately below the plot controls, the zero point coordinates of the plots and the source of this zero
point is given. The zero point source will change as processing in the project progresses: first an un-
weighted mean of the OPUS solutions from the mark’s data files is used, then an unweighted mean of
any session processing results, finally, an unweighted mean of any network adjustment results.
The plot axes are automatically defined to encompass all points plus the error bars for session solution
and network adjustment results only. As a result, the error bars for OPUS solutions may extend beyond
the plot and not be entirely visible. There is logic to this design. Although it is unlikely, there are cases
where the OPUS error bars are so large that they would shrink the meaningful
part of the plot, the
points themselves, to inscrutability. Note that the orange shaded regions that indicate solutions that fail
to meet the project’s preferences may not appear if all solutions meet those preferences (see the
examples in Figure 1.73).
Four plots are shown:
North versus East (sometimes called a horizontal coordinate scatter plot) to the
upper-left,
Up versus GPS Time (ellipsoid height time series plot) to the upper-right,
East versus GPS
Time (longitude time series plot) in the lower-left and
North versus GPS Time (latitude time series plot)
in the lower-right. Each point in these plots will have the corresponding uncertainties plotted as error
bars. There are three items to note. First, the results displayed are in centimeters not meters. Second,
the uncertainties for a result can be so small as to make the error bars difficult to distinguish. Finally,
the North versus East plot will always be a square with identical tick intervals to facilitate visual
comparison of the north and east results. For this same reason, the east and north axes on the East
versus GPS Time and North versus GPS Time plots will be the same size with the same tick interval.