 |
        |
           |
|
|
|
Low Cost GPS Receiver and Moving Map PC Software Reviewsby Joe Mehaffey and Jack YeazelRevised: 20 June, 2000 (Corrected for SA elimination and other details) Quoted prices are US$ MAGELLAN RECEIVERS Magellan GPS-4000 (& XL versions): This $250 receiver has good display features and acquires satellites reliably except in dense woods or close to hills causing reflections. It has a $50 accessory to permit connection of external DC power and an optional external amplified antenna at about $100. This unit has about the best battery life at roughly 17 hours (24 hours with the newer XL version) on one set of 4 AA batteries. This unit has a two-channel multiplexed 12 satellite tracking ability (advertised). However, we note that when one of the four satellites it is using to provide data suddenly becomes unavailable (such as when you go behind a hill or a building) the GPS 4000 must go through a reacquisition sequence even though the status display indicates it is "tracking" 8 satellites. This reacquisition can take 30 to 120 seconds depending on conditions. However, a TRUE 12-channel version of the 4000XL has been produced without changing the name. The only identification of these receivers is by the Model No.: 00-62014-010. Magellan GPS-2000XL: It is the survivor of the old M-2000/3000/4000(XL) line. It incorporates most of the features of all three products and includes a sensitive 12 channel Parallel receiver. The M-2000XL can upload/download waypoints using Ozi Explorer and Street Atlas 5 mapping software. This unit is robust and provides user features quite similar to Garmin's G-12 (not XL). Disadvantages: The batteries must be removed and an adapter module installed in order to operate on external power, use an external antenna, or connect to a computer. See: Garmin G-12 Compared to Magellan GPS-2000xl and GPS-4000 Magellan ColorTrak v 2.01 (Thanks to Dale DePriest). The ColorTrak has a color display, external alarm support, a pressure sensor to improve altitude readings, a back-lit keypad and a carrying case. The battery compartment is actually two independent halves that you must unscrew to remove the batteries. They seem to be two parallel sets so the unit must run on 3 volts and in a pinch it could be operated with only two batteries. Many screens now have additional data and match their Garmin counterparts instead of the older single function screens. The plot screen still looks and works like the older units except that it now has icons, a long track log and the ability to show a single distance circle similar to the 3 Garmin circles. There doesn't seem to be an active route screen in the rotation and I wasn't able to determine how to review route data very well from my brief encounter. The screen is definitely taller than a Garmin screen. The interface looks like a Garmin connector except that it has 5 pins. There is a simulator mode on the system menu. It has two settings, one automatic for training and one user mode that you can specify the speed and bearing. Other notable features are a graphic indication of the position of the sun and moon so that you can use the unit as a crude compass while standing still, automatic position averaging (as compared to Garmin's manually initiated pinning feature), and a battery gauge that seems to do something more than just measure voltage. One feature that the 4000XL had that seems to be missing from the new units is the ability to set a waypoint by measuring inches or centimeters on a map. The "altimeter" in the ColorTrak is not really an altimeter, but is a pressure sensor that is used to help the software decide whether the change in GPS altitude is a real change in altitude, or is just due to SA or other physical effects. The pressure measurement is examined for changes and if the GPS jump is large and varying (say jumping up and down as frequently happens with SA), then the 3D solution is damped to reduce the motion in altitude. On the other hand, if the change in altitude continues, then the altitude is allowed to continue in the direction indicated. The GPS will indicate the 35,000 feet that your 747 is at, despite the cabin pressure of 6000 ft. The GPS computed altitude takes precedence, just that the variations are damped. Most Magellan receivers will not show altitudes below sea level "to reduce boater complaints". See: Magellan ColorTrak Receiver -Review Contents
|
Sponsored by: For information regarding advertising rates Click Here! |
Copyright© 1995-2012 MindSites Group / Privacy Policy
GeoCommunity™, Wireless Developer Network™, GIS Data Depot®, and Spatial News™
including all logos and other service marks
are registered trademarks and trade communities of
MindSites Group