Unable to do differential data correction on data collected using ALTO-G12

“The last time I performed a successful differential correction was a month ago. I have been having trouble with the differential correction ever since. The message it gives me is that there is no data for the base stations. Also, how would I set up the GPS so that it collects raw data?”

In the differential correction screen there is a box for specifying the folder the contains the base files. Make sure that location agrees with where you have placed the downloaded base files

The ALTO-G12 data collector records the raw data by default.

If the base files are not downloaded, the jobs cannot be processed. Did something change on your computer or your network system to prevent the base files from being
downloaded automatically?

Are the firewalls on your PC or an antivirus or antispyware program preventing the ftp access to the NGS CORS site? Please add (or ask your IT person to add)
PCGPS09.EXE to the firewall and antivirus or antyspyware exception lists.

If you are able to access the CORS site outside of PC-GPS 09, you could try the manual procedure for downloading the base files. It is outlined below.
1. You can obtain the CORS Rinex data via non-ftp site through the world wide web. Please use the following address:

2. You will need to download the “RINEX data” and also the “Global Navigation” data (under the non-site specific section) for the day and base station you need.

After downloading and unzipping the data, you will be left with the file extensions: *.17o and *.17n for the 2017 files.
The file prefixes also need to match.
The global ephemeris file has a generic name like: brdcxxx.07n.
Please rename the file prefix to match the *.17o file. For example, if the *.17o file is named: fts11230.17o, then rename the brdc1230.17n file to be: fts11230.17n.

For example PIT1238A.gz is the base file from “Pittsburgh 1” for the first hour (A) of the 238th Julian Day.The unzipped raw correction file is named: PIT1238A.17o.
Rename the ephemeris file brdc1238A.17n to PIT1238A.17n.
Write down the LLA coordinates of the base station.

3. Put the PIT1238A.17o and PIT1238A.17n files in your PCGPS9 folder and point to the folder in the differential correction function.

In the differential correction screen, click the Setup button then select Base Management. Click NEW then add the new base station name and coordinates.

Back in the main differential correction screen, select the base station name.

When you move the rover files into the Selected Jobs section, the matching base files will be highlighted in the Files panel. Then click the Differential button to perform the
differential correction.

Unable to connect to Google Earth using PC-GIS X

“For the past several weeks we have not been able to load google earth imagery in the software on the pc. It says failure to connect. Has something changed?”

Sometimes an automatic Windows update may change the registry on your PC. When Google Earth is not registered properly, our PC software will not be able to connect to it.

Please log into your PC as the administrator.
Click on the Windows icon and enter “cmd” in the Search box.
Run cmd.exe to open a Windows command prompt (a black screen).

At the command prompt type the path for the folder in which Google Earth is installed. For example, type

“c:\Program Files (x86)\Google\Google Earth\client\googleearth.exe” /RegServer

then press the Enter key on your keyboard.

If your googleearth.exe is installed in a different folder, please enter that full path on the PC in the above line. Please do no omit any quotation marks. There is a space before /RegServer in the above line.

Should you get an error message about your not having administrative privilige, you could put the above line into a text file and save the text file as RegisterGoogle.cmd then right-click on this file and choose “Run ad administrator”.

Now run Google Earth then try using PC-GIS X to Launch Google Earth then zoom into the area of interest and capture an image.

Windows 7 issue – Program won’t run.

“I successfully downloaded and installed PC-GIS 09. However my Windows 7 PC will not execute the software program.”

This problem is due to the Windows 7 security setup. You can resolve it as follows:

First, uninstall PC-GIS 09 by using Windows – Control Panel – Programs – Uninstall Program.

Then right-click on PCGIS9WEB.exe and select “Run as administrator“. When Windows 7 informs you that PC-GIS is trying to make changes to the system and do you want to execute it, in that pop-up window there is a link to change the security level. Please change it to 0 (zero) then select Yes. The installation should go through and the program should run.

Same for installing PC-GIS X and our other PC application software programs.

I am interested in the PC-GIS upgrade from version 7 to version 9. What are the new features in version 9?

The enhancements in version 9 of our various PC GPS/GIS mapping application software can be found at the following link:


Need help adding the bottom part of the basemap … can we add more than one basemap?

Yes, you can load more than one basemap to each Job.
Please select Utilities – Load/Change Basemap and unmark the checkbox for “Free original basemap”. Then select the desired additional basemap to load.

Aligning Deed Plot with the map in PC-GIS X

“Knowing that the previously drawn boundary has errors, I am seeking to draw out the survey calls and see if I can search out the boundary from those…knowing the survey is not recent. With that, when I plotted it out for whatever reason the boundary shape is not oriented around properly. Did I do something wrong when I entered? Is there a option to start at a mouse selected starting location and then have the plotter plot the calls from that starting point? . . . I do not know how to rotate a shape.”

There are discrepancies between your deed calls and the reference map.

On the Feature Information screen for the deed plot, please set the orientation for the deed plot to 172 degrees to rotate it then drag it to try to match a corner with the corresponding corner on the plot.

The deed calls may have the north and south reversed. Also, it is probably referenced to magnetic north and therefore has an angle of declination to account for.

With respect to the location of the plot, you can specify the coordinates of the point of beginning on the Feature Information screen before entering the calls.

Just curious what the differences are with PCGPS PRO vs PCGPS09 ?


The main differences between PC-GIS PRO and PC-GPS 09 are:

1. PC-GPS 09 provides GPS differential correction functions for people using our GPS data collectors (MC-GPS, MARCH II-E, ALTO-G12). PC-GIS PRO is for the other users who do not need differential correction functionality. Users of our FieldCE GIS app for Windows Mobile PDAs normally use PC-GIS PRO as FieldCE GIS only works with real-time GPS data and does not record raw data for differential correction. PC-GPS 09 is more expensive than PC-GIS PRO.

2. PC-GPS 09 provides COGO functions for creating new points using coordinate geometry. PC-GIS PRO does not.

3. PC-GIS PRO provides a Navigation function for use with an external GPS receiver that sends out NMEA messages. PC-GPS 09 does not as it is mainly for use by our GPS data collector users.

4. Now we also have iOS apps for GPS/GIS data collection. PC-GPS 09 and PC-GIS PRO are compatible with iGPSGIS II (for iPhone) and iCMTGIS II (for iPAD). Our PC-GIS X is compatible with iCMTGIS III and iCMTGIS PRO, both of which can run on iPad or iPhone devices.

There are a few other differences within certain functions or utilities. Please send email to support@cmtinc.com if you have questions about any specific functionality.