Index: trunk/BNC/src/bncwindow.cpp
===================================================================
--- trunk/BNC/src/bncwindow.cpp	(revision 6753)
+++ trunk/BNC/src/bncwindow.cpp	(revision 6754)
@@ -1133,5 +1133,5 @@
   _sp3CompFileChooser = new qtFileChooser(0, qtFileChooser::Files);
   _sp3CompFileChooser->setFileName(settings.value("sp3CompFile").toString());
-  _sp3CompFileChooser->setWhatsThis(tr("Specify the full path to two files with orbits and clocks in SP3 format, separate them by comma."));
+  _sp3CompFileChooser->setWhatsThis(tr("<p>BNC can compare two SP3 files containing GNSS satellite orbit and clock information.</p></p>Specify the full path to two files with orbits and clocks in SP3 format, separate them by comma.</p>"));
   _sp3CompFileChooser->setMinimumWidth(15*ww);
   _sp3CompFileChooser->setMaximumWidth(40*ww);
@@ -1143,5 +1143,5 @@
 
   _sp3CompLogLineEdit = new QLineEdit(settings.value("sp3CompOutLogFile").toString());
-  _sp3CompLogLineEdit->setWhatsThis(tr("Specify the full path to a logfile."));
+  _sp3CompLogLineEdit->setWhatsThis(tr("<p>Specify the full path to a logfile to save comparison results.</p><p>Specifying a logfile is mandatory. Comparing SP3 files and not saving the results on disk would be meaningless.</p>"));
   _sp3CompLogLineEdit->setMinimumWidth(15*ww);
   _sp3CompLogLineEdit->setMaximumWidth(15*ww);
@@ -1318,5 +1318,5 @@
   _serialFileNMEALineEdit->setWhatsThis(tr("<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved.</p><p>Default is an empty option field, meaning that NMEA messages will not be saved on disk.</p>"));
   _serialHeightNMEALineEdit->setWhatsThis(tr("<p>Specify an approximate 'Height' above mean sea level in meters for the reference station introduced through 'Mountpoint'. Together with the latitude and longitude from the NTRIP broadcaster sourcetable the height information is used to build one initial GPGGA message to be sent to the NTRIP broadcaster.</p><p>This option is only relevant when option 'NMEA' is set to 'Manual'.</p>"));
-  _serialManualNMEASamplingSpinBox->setWhatsThis(tr("<p>Select the sampling interval in seconds for manual generated NMEA string. A sampling rate of '0' means, the NMEA string will be send only once. </p>"));
+  _serialManualNMEASamplingSpinBox->setWhatsThis(tr("<p>Select the sampling interval in seconds for manual generation and upload of NMEA GGA sentences.</p><p>A sampling rate of '0' means, the a GGA sentence will be send only once to initialize the requested VRS stream. Note that some VRS systems need GGA sentences at regular intervals.</p>"));
   _reqcActionComboBox->setWhatsThis(tr("<p>BNC allows to 'Edit or Concatenate' RINEX v2 or v3 files or to perform a quality check and 'Analyze' the data following UNAVCO's famous 'teqc' program.</p>"));
   _reqcEditOptionButton->setWhatsThis(tr("<p>Specify options for editing RINEX v2 or v3 files.</p>"));