Navigation:  Tutorials > Measurement tutorials > GPS acquisition > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Channel setup

When GPS is selected in the Hardware setup, we get another tab in the setup screen. We have several channels to choose from - position in x, y and z axis, velocity, vertical velocity and direction, used satellites, mark input (the external event) and the current second of the day. The acceleration and distance are calculated from the velocity channel.

On the bottom, we have a sky map that, shows the current satellite constellations in the sky. The satellites that which are being currently used at that moment are drawn in green (if the receiver supports GLONASS, then the satellites are shown in red) and the color shows the strength of the signal. Pale green signifies a weak signal and dark green is a strong signal. Then we have information about whether PPS sync is available. This is information about the receipt of the pulse per second signal over the GPS interface (RS232 or USB), which can, if available, enhance a synchronization to other data source a lot. If the PPS sync is not available, we need to switch it off in the DEWESoft Tuner utility under the GPS section in order to receive the data from such GPS. Usually this signal is available, but some recent low cost receivers don't have this.

Further, if the receiver supports differential mode from SBAS or WAAS and these signals are used, this will be shown in the Differential mode indicator.

 

When we choose the channels, we can take some measurements. A part of setting up the GPS is to assign a map to the GPS display. Now let's take a look how to add a map behind traveled path of the GPS. If we have a map of the area in either bmp or jpg format, we can adjust it to the GPS.

If we don't know the coordinates of the map, we can take a short tour in the area storing the measurement. Then we go to the GPS screen, go to Calibration and Load map. The map is shown in the background, and the traveled path gets four handles around it. Now we can drag and adjust those handles to match the position and the map.

If we know the exact coordinates on the map, we can also enter them by switching to the Calibrate from points mode. Once this is adjusted, we can Save calibration file. From that point on, this map will always be shown behind each measurement. We can also have multiple files for different zoom levels. We can have an overview file like this, and when we zoom in, it will switch to the picture. Now is a good time to go for a drive and see what this looks like.