1997 Volume 43 Issue 2 Pages 79-90
It is known that a phase measured by a GPS survey antenna is affected by the direction of the source of satellite radio waves. We previously measured this phasecharacteristics of several types of GPS surveying antennas. Recently, more advanced GPS surveying receivers have been used for surveys and geophysical observation. Wetherefore nce again carry out measurement tests on phase characteristics of the newtypes of antennas. This yields phase characteristics of the GPS antennas at the frequencyof Ll and L2 with respect to the azimuth and elevation angles. The differenceof phase characteristics between the same type of antennas and different types of antennas is also measured. Effects of frequency modification for code signals are also investigated by measuring phase characteristics on eight different frequencies, 1 and 10 MHz apart from L1 and L2. It is found that the variation of measured phases with the direction change of the radio source becomes a little amaller compared to those of the antennas used in the former experiments. This may be achieved by technical refinements of antennas.
