81FeaturesMap Datum - Offers a selection of nearly all map datums in common use. Every map is basedon a map datum (a reference model of the earth’s shape) and is usually listed in the title blockof the map. If you are comparing GPS coordinates to a paper map, chart, or other reference,the map datum in this field must match the horizontal map datum used to generate the mapor other reference. The default datum is WGS-84 (World Geodetic Survey 1984) and shouldonly be changed when using maps or charts specifying a different datum. If a map does specifya datum, use the options list to find datums applicable to the region of the map, selecting theone that provides the best positioning at a known point. If necessary, you also may choose the‘User’ datum for custom designed grids.NOTE: The ‘User’ datum is based on a WGS-84-Local datum and is an advancedfeature for unlisted or custom datums. To learn more, check your local library or theInternet for educational materials on datums and coordinate systems.Distance/Speed - Choose from three units of measure to display your rate of travel.Elevation/Vertical Speed - Choose from two units of measure to record your elevation andvertical speed.Pressure - Choose from millibars or Inches to measure the pressure.Display Setup PageYou can adjust the amount of time that the backlighting feature stays on and adjust thescreen contrast.Backlighting Timeout - Choose from Stays On, to delays of 15 seconds, 30 seconds, oneminute, or two minutes before timing out.Setup PageUnits Setup Page
