Also the Vista has a very weak signal from satellite number 7, whereas the Vista HCx has a full-strength signal. The signal strengths have no scale associated with them so it is difficult to compare them, but it can be seen that the HCx has obtained a strong signal from satellite number 25, whereas the older Vista has not got a signal at all. There is a small discrepancy with the marked position of satellite number 13 on these pictures though. The satellites can be seen at approximately the same positions in the sky, and are shown with the same numbers. However, the information presented is largely the same. Screenshot of satellite view from both units,Ĭosmetically, the main obvious difference is that the older unit only has a greyscale LCD screen, and has a greater number of pixels than the newer HCx unit with its colour TFT display. Immediately, several differences between the two receivers can be observed. The unit displays on the other hand show the positions of each satellite, the strength of the signal, and the calculated coordinates and estimated accuracies, as can be seen in the screenshot below. In order to analyse the receivers' view of the satellites, it was necessary to take screenshots from the receivers as the stored tracklogs do not contain information about the satellites. This is of course rather difficult to confirm. So the effect should be to attenuate the signals rather than to produce misleading, false signals.

It is expected that the tree will absorb some of the incoming GPS signals but probably not reflect them. The sky was not obstructed by buildings but the units were located near the base of a medium-sized tree in order to test reception under suboptimal conditions. We attempt to show a side-by-side comparison of the two units' readings, using both screenshots of the satellite view and the recorded coordinate data.ĭuring the readings, the units were kept stationary, next to each other, and with the same orientation (with the screen facing upwards). This is a second analysis comparing the performance of two Garmin GPS receivers, an etrex Vista and an etrex Vista HCx.

Garmin etrex vista nmea output gps