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Creating and Using a Trajectory from Google Earth

Use this process to convert a Google Earth kml file to an NMEA GGA file for use by the scenario generator.

Create a Google Earth Trajectory File

1. Start Google Earth on your PC.
2. Click Get Directions, enter location A, and enter location B, then click Get Directions to show the path from the hotel to Keysight office.
3. Click Copy the current search results to My Places button under the directions to add this path to My Places, then right click on the path you’ve created and Save Place As a KML file.

Use the N7609C Software to Convert Google Earth kml to NMEA GGA

1. If playing a scenario, click the State Off button.

2. In the tree node, click the Trajectory Generator node.

3. Click on the to launch the KML to NMEA Converter dialog box.

   

4. On the KML to NMEA Converter dialog box:

   1. Click KML file to launch the Open dialog box to navigate to and open the saved Google Earth kml file.

      After selecting the kml file, the file path and name appears to the right of the KML file button..

   2. If desired, change the file properties for the conversion.

5. Click the Convert button to launch the Save As dialog box for selecting a location and saving the file as an NMEA GGA file type.

6. After saving the converted NMEA GGA file, click the to close the KML to NMEA Converter dialog box.

Load the NMEA GGA File into the Scenario Generator

1. Click the Scenario Generator node.

2. Click the Scenario Type cell and use the drop-down arrow to select Dynamic.

   With the Dynamic selection, the NMEA Message File cell appears .

3. Click the NMEA Message File cell, and use the dialog box button to launch the Open File dialog box for navigating to and selecting the converted NMEA message file.

   After selecting the file, the Start Time (GPS Time) cell automatically updates to the start time from the GGA file.

   The start time in the scenario generator uses GPS time versus UTC time for the Start Time property of the KML to NMEA Converter. Because of the different time types, the scenario generator start time will always show a number of leap seconds later than the KML to NMEA Converter, Start Time property.

4. Change the date of the Start Date cell to match the date of the almanac file.

   For the factory supplied almanac files, the date is part of the file name or you can view these almanac file dates in the Factory Supplied GNSS Files topic.