Garmin GPS 400W,GNC 420W Pilot's Manual & Reference

Also see for 400W Series: Supplemental Flight manual Pilot's guide addendum Manual supplement Pilot's guide addendum Quick reference guide

Contents

Garmin GPS 400W,GNC 420W Pilot's Manual & Reference Manual pdf 65 page image

2 - NAV PAGES55Satellite Status PageSatellite Status PageThe Satellite Status Page is helpful in troubleshoot-ing weak (or missing) signal levels due to poor satellitecoverage or installation problems. You may wish torefer to this page occasionally to monitor GPS receiverperformance and establish a normal pattern for systemoperation. Should problems occur at a later date, youmay find it helpful to have an established baselinefrom which to compare.GPS ReceiverStatusSky Viewof satellitepositionsSignalStrength BarsPage locationin NAV groupSatelliteNumbersHorizontal Figure of Meritand Vertical Figure of MeritEstimated Posi-tion UncertaintyAcquiringSatellite,not readyfor useExcludedSatellite(cyan)Satelliteacquiredand used forposition fix(green)Satellite acquired, used forposition fix, and has differentialcorrectionsAs the GPS receiver locks onto satellites, a signalstrength bar appears for each satellite in view, with theappropriate satellite number (01-32, WAAS satelliteswill have higher numbers) underneath each bar. Theprogress of satellite acquisition is shown in the follow-ing conditions:• Hollow signal strength bars — the receiver has foundthe satellite(s) and is collecting data.• Cross-hatch cyan signal strength bars — the receiverhas found the satellite(s) but it has been excludedby the FDE program as a faulty satellite.• Solid cyan signal strength bars — the receiver hascollected the necessary data, but is not using thesatellite in the position solution.• Solid green signal strength bars — the receiver hascollected the necessary data and the satellite is beingused in the position solution. The sky view display(at top left corner of the page) shows which satel-lites are currently in view, and where they are. Theouter circle of the sky view represents the horizon(with north at top of the page); the inner circle 45°above the horizon; and the center point directlyoverhead.The “D” character inside the bars indicates differ-ential corrections (e.g. WAAS) are being used for thatsatellite.Each satellite has a 30-second data transmissionthat must be collected (hollow signal strength bar)before the satellite may be used for navigation (solidsignal strength bar). Once the GPS receiver has deter-mined your position, the 400W-series unit indicatesyour position, altitude, track and ground speed. TheGPS receiver status field also displays the followingmessages under the appropriate conditions:• Searching Sky —The GPS receiver is searching the sky for ANY vis-ible satellites. You are also informed of this statuswith a “Searching the Sky” message.• Acquiring Sat —The GPS receiver is acquiring satellites for naviga-tion. In this mode, the receiver uses satellite orbitaldata (collected continuously from the satellites) andlast known position to determine the satellites thatshould be in view.