Pgps-qg-001 Gps Pinnacle Post Processing

Quick Guides PGPS-QG-001 GPS+ Software

Post Processing Static GPS Data using Topcon Pinnacle

Before getting started, if you wish to relate the information to OS Datum, you will need to download the relevant OS Rinex data from the OS GPS Network website available at www.gps.gov.uk. You will need to be registered to use this service, however this doesn’t cost anything and you can register at any time. To download the data you will need to follow the links for Active Rinex Data, log in and then enter appropriate details for your required site:

You will need to enter the following information:

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1. Approximate location of site. This can be either as OS Grid Eastings & Northings, OS Grid Reference or as ETRS89 GPS Coordinates.

2. How you wish to select OS Active Stations; either by number of nearest ones or by a search radius. 3. The date of the occupation 4. The start and end times of the occupation, note these should be in Greenwich Mean Time rather

than British Summer Time (if relevant)

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5. A project name; this is the name that will be ultimately given to the archive zip file that you download containing the Rinex data.

Click on the Sea ch link and you will be presented with the next web page letting you know which stations are available:

As can be seen by the above image, some of the stations that you have selected may not be available and you will be alerted to that fact. Click on the Process link to continue and you will receive confirmation of the number of stations that you will be using. The final page confirms the stations, date and times that you have selected and invites you to click on the Zip icon to download the data:

Save the file to an appropriate place and once it has downloaded, extract the all of the files to a location that you can browse to later on. Load up Pinnacle and from the main screen (if it doesn’t happen automatically) select the New Project toolbar icon to get started:


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Select an appropriate folder and if needs be create a new folder name and press OK,

and enter the appropriate details (Name as a minimum) in the Project Properties dialog box…

Having completed this, a new window will appear which will contain all relevant project networks and data. At this stage, you will need to import control data that you will ultimately wish to reduce your adjusted GPS survey to. For this exercise, we will import OS Control data which can be easily obtained from the previously mentioned OS website. To import it, right click on the main Project icon and from the shortcut menu, select Control Data:


This may result in the Con rol Data Wizard starting up which you can work through if you wish. Otherwise, select the second toolbar icon to import the file.

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You can import a number of formats, the default being a *.jcp extension. Locate the file and import it:

Quit out of the Control Data window to continue. Each project can contain multiple Networks, to start a new one, right click on the Project name and select the New Network menu option. You will then be prompted to enter a new name for the network or leave it as the default New Network:

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Now you can start to import data collected from your Topcon receiver(s) along with any OS Rinex data. Right click on the Network name and select Import and from the next screen that appears click on the first

toolbar icon to browse to where you GPS data is located. Note the various file formats that you are able to import. For OS related projects, you will need to import Receiver Log files (*.tps, *.jps) and both of the Rinex file types…

Quick Guides PGPS-QG-001 GPS+ Software N.B. if all relevant files in are in one folder, simply select All files to import all data files. Once the files have been imported, they will be displayed ready for processing:

Select the Start button and the import process will commence, finally displaying whether each source file data has imported okay and a report at the end of the window. Quit from the import view.

You will now see that your data is now available under the Raw Data Sessions (which you can rename if needs be).

You can now access an occupational time view of this data by right clicking on the Session name…

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Quick Guides PGPS-QG-001 GPS+ Software At this stage, you can select an observation and split it into any number of smaller observation times. In the above figure, an observation time of five days has been split into day intervals and all apart from the data from 21st September has been removed. Before going any further, it is crucial to ensure that the antenna information for each of the receivers is correct; otherwise incorrect results will be processed. From the main Project window, right click on each point in turn and from the resulting shortcut menu, select Properties and then Antenna.

You should firstly make sure that your Antenna Height is entered correctly and is of the right type, but you must also make sure that the correct Antenna Type has been identified. Click on the antenna Properties button to access information about the antenna and if not correctly identified, you will see that there are no Offsets shown. In this situation, select the Alias of drop down and find the relevant antenna to add these values. In some cases, this information won’t be available and you will need to enter a new antenna from scratch. From the main Tools menu, select Devices Editor and make sure the appropriate antenna isn’t available under a slightly different name. If not, select the New button and start entering the details:

And then click on the Phase Center Variations button to add the details for the GPS L1 & L2 settings:

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Press OK and then quit out of the dialogs. To continue with the processing, drag the entire Session from the Raw Data Session into the Solutions section and the following Session Process Properties dialog appears. Make sure you have

Static Solution selected, and then click on the Engine tab and then Properties. Make sure that the

GLONASS system is unchecked, then from the Advanced tab, make sure the Apply Phase Center Variations and Apply Ionospheric Model (L1 & L2c only) options are ticked and from the Troposphere tab, ensure that

Quick Guides PGPS-QG-001 GPS+ Software you have Estimate Zenith Troposphere Delay selected. Take a while to look over the various other settings to satisfy yourself that everything is okay.

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rPress OK on the Session P ocess Properties dialog and the session will appear in the Solutions section. You can now right click on this session process and from the shortcut menu, select the Network View option to see how your network appears. Close this window to continue…

From the same right click menu, select Run Process to start processing the session data…

This may take a long time, depending on how much data is being processed. Once the processing has been completed, expand the Process Queue tree to check for problems. These will be signified by any non-green symbols. You may need to drill down quite a way to find out where the source of a problem may lie. Any warnings / errors will usually be of a small nature at this stage. If you receive any symbols such as shown below then you will need to recheck your data…

Error Fatal Error Fault


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Once the process has completed satisfactorily, quit out of the results window and again drag the current session from the Process section through to the Subnets section to adjust the GPS survey. Right click on the current session in the Subnet section and from the shortcut menu, select Properties and then the Parameters tab. Make sure that System/Datum option has been set to ETRS89…

then press OK and then from the same right click menu, select Run Adjustment to adjust the data without tying it into to any ‘local’ control.

Quick Guides PGPS-QG-001 GPS+ Software The results of the adjustment will be displayed as shown below, i.e. a network view on the left with a summary listing on the right hand side.

If you find that some vectors are flagged up as being in error, then you can disable them from the process by right clicking on that particular vector and selecting Disable in Subnet. Points can be similarly disabled from the Subnet. We can now fix the OS Active Network stations to the control data that we imported at the start of this exercise. Close the results window down and from the right click menu, select A tach Con rol Point. If your system is set up correctly, then selecting each point in turn from the Points to Attach column will activate the relevant data in the Control Point item section. Select both items and press on the Attach button.

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Repeat this for each OS control point, leaving one floating for the time being. Click on the Close button, and then run the adjustment again. You will now see that the control points that you attached to OS data have now got different symbols denoting that they are fixed control. However, one control point (DARE in this case) was not fixed. This was to enable us to check whether the adjustment has completed as anticipated. We can check this now by comparing the ETRS89 position derived of DARE with the published OS active network coordinates of that point.

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Right click on the point in question and bring up its Properties. Click on the Combined Adjustment Properties tab and select XYZ as the System type. Note the coordinates and compare with the published OS coordinates.

In the above left example, the published coordinates for DARE are X 3811965.6033m, Y -175800.0541m and Z 5093615.4808m which compare with the derived results shown above as: X -4.4mm, Y 8.8mm and Z 2.6mm which is fine. Once you are happy with this, go back to the current Subnet session and attach the remaining control point (i.e. DARE) and re-run the adjustment. This will then compute your final ETRS89 coordinates for your GPS station. Again, view the final coordinates by right clicking on the point, selecting Properties and then checking the Combined Adjustment Coordinates (above on the right). These coordinates are ETRS89 Cartesian coordinates, so you will now have to transform these to OSGB36 coordinates using a software tool such as Grid Inquest 6.0. Don’t try using any earlier versions of Grid Inquest as they don’t provide transformations to OS coordinates using OSTN02 and reduction to ODN via OSGM02. For instance Inquest 5.0 uses the OSTN97 transformation model and OSGM91 geoid model. To transform theses cartesian coordinates, fire up Grid Inquest and select which area you are mapping in (i.e. Great Britain).


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From the resulting screen change to the ETRS89(xyz) tab and enter your newly derived coordinates into the appropriate fields (note that any changed fields become red in colour)

When you have entered the coordinates, click on the button with the right hand to get your new OSGB36 easting, northing & ODN height…

You are also able to create reports from within Pinnacle covering the Subnet Adjustment, the Processing and the Import of the data. Do this by right clicking on any of the session entries, selecting Report… and choosing which options you wish to include in the report and what format it should take. The following dialog shows the options that are available for Subnet report creation. Use the mode to choose how you would like the report to be saved and then either select Run Default to show the report in Pinnacles internal browser or Run to File to produce a standalone file which can be loaded up in Word, Internet Explorer, etc.


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You may receive the following dialog to confirm which coordinate system type you wish to have the results displayed in:

The following shows an HTML saved report loaded into Internet Explorer:

Documents

Pgps-qg-001 Gps Pinnacle Post Processing