User manual TRIMBLE GPS PATHFINDER OFFICE 2.80 GETTING STARTED GUIDE REV A

[. . . ] GPS Pathfinder Office ® Getting Started Guide GPS Pathfinder Office Getting Started Guide Version 2. 80 Part Number 34231-28-ENG Revision A March 2001 Corporate Office Trimble Navigation Limited Mapping and GIS Division Technical Publications Group 645 North Mary Avenue Post Office Box 3642 Sunnyvale, CA 94088-3642 U. S. A. Phone: +1-408-481-8940, 1-800-545-7762 Fax: +1-408-481-7744 www. trimble. com Copyright and Trademarks © 1999­2001, Trimble Navigation Limited. For STL support, the GPS Pathfinder Office GPS Pathfinder Officesoftware uses the Moscow Center for SPARC Technology adaptation of the SGI Standard Template Library. Copyright © 1994 Hewlett-Packard Company, Copyright © 1996, 97 Silicon Graphics Computer Systems, Inc. , Copyright © 1997 Moscow Center for SPARC Technology. [. . . ] This lesson shows you how to: · differentially correct the field data collected by your three field crews It takes approximately seven minutes to complete. GPS Pathfinder Office Getting Started Guide 81 4 Tutorial To differentially correct the field data: 1. In the GPS Pathfinder Office software, click the Differential Correction tool , or select Utilities / Differential Correction. The Differential Correction utility appears: 82 GPS Pathfinder Office Getting Started Guide Tutorial 4 2. In the Rover Files group, click Browse to select the data files to be differentially corrected. The following dialog appears: By default, the Pfdata\Tutorial folder is selected, as this is the default folder for data files that was defined when we selected the project (see Selecting a Project, page 66). There are three data (rover) files available that have the filename of `TutdataX. ssf'. These data files were collected at the same time by three different field crews. Select the three files Tutdata1. ssf, Tutdata2. ssf, and Tutdata3. ssf, then click Open to confirm the selection and close the dialog. Tip ­ To select the three files, click Tutdata1. ssf, hold down >&WUO@, and click Tutdata2. ssf then Tutdata3. ssf. The three files appear in the Selected Files field in the upper left portion of the dialog. GPS Pathfinder Office Getting Started Guide 83 4 Tutorial 4. In the Base Files group, click Local Search to select the base files. The following dialog appears: This dialog lets you set a folder from which the software automatically selects base files, based on the start and end times of the rover files. Make sure that the Folder field contains the base folder as defined in the Tutorial project. When the search is complete, the following window appears: 6. 84 GPS Pathfinder Office Getting Started Guide Tutorial 4 The dialog shows the three data files, which were collected in the field, along with their start and end times. This indicates that the data file is completely covered by the base files that have been found in the base files folder for the project. We will use these two base files to differentially correct the rover files. The Reference Position dialog appears: The reference position is the known location at which the base files were collected. Note ­ As these base files come from a Community Base Station, the displayed reference position is accurate and correct. However, if you collected your own base data, the reference position could be incorrect or absent. In this case, you must know the reference position and enter it in this dialog. An inaccurate reference position will result in errors in the corrected data. GPS Pathfinder Office Getting Started Guide 85 4 Tutorial 8. Click OK to confirm the reference position. The data files and base files are now displayed in the Differential Correction dialog. This is the extension that the differentially corrected output files will have. For example, the corrected version of Tutdata1. ssf will be called Tutdata1. cor. 9. In the Processing group, make sure the Smart Code and Carrier Phase Processing option is selected. This is the default setting and it is the most thorough type of processing. 10. Confirm that the settings are the same as shown here: 86 GPS Pathfinder Office Getting Started Guide Tutorial 4 11. [. . . ] The file may not exist if it is outside the hours logged by the server. For example, some base stations only log data for normal working hours. Also, the base station may have been put out of service during the required time period. It is possible that the specified directory is incorrect, perhaps because the provider has changed the server configuration. [. . . ]