TH-D72A/E - N3UJJ

4 GPS4.2.4 Settings for Geodetic Survey SystemFor APRS, always configure the WGS-84 Geodetic Survey System for your GPS receiver.4.3 Internal GPSThe GPS unit is mounted on the upper surface of the body. The GPS unit incorporates SiRFstar IIIchipset that is highly accepted in the market.Figure 4-4 Internal GPS Unit4.3.1 GPS Satellite Information DisplayDuring the GPS positioning, you can check the current status on the GPS satellite informationdisplay.The GPS satellite information display provides real-time data of the sky view, satellites’ signalstrength and status of the positioning. The display also helps you to get better reception by changingthe direction of the GPS antenna or making any other adjustments.1 Sky ViewThe positions of the satellites indicated by the satellite numbers are plotted on the satellite locationchart. The satellite location chart shows the azimuth and elevation of the satellites. The outercircle expresses the 360° of the azimuth. The sign of “N” at the top indicates North, the rightcorresponds to East, the bottom to South and the left to West accordingly. The elevation isrepresented by the proximity to the center; the outer circle shows 0° (horizontal position) and thecenter indicates 90° (zenith). Observing the satellites’ positions, you can see they move little bylittle over time.2 Signal strength of the satelliteThe signal strength is indicated by the bars appearing on the top of each satellite number. The baris based on a 15-point scale. The solid bar indicates the satellite is used for GPS positioning andonly the frame of the bar means the signal of the satellite is received but not used for positioning.3 Status of positioning• “2D” indicates the unit receives signals from three GPS satellites to perform two-dimensionalpositioning with latitude and longitude.• “3D” means the unit receives signals from more than four GPS satellites to perform threedimensionalpositioning with latitude, longitude and altitude.TH-D72A/E CONTENTS 27From The N3UJJ.COM Document Library