Article 27994 of sci.geo.satellite-nav: Path: matra.meer.net!news.spies.com!news.sgi.com!news.mathworks.com!newsfeed.internetmci.com!news.webspan.net!ix.netcom.com!netcomsv!uu3news.netcom.com!netcomsv!uu4news.netcom.com!void.agames.com!randy From: randy@agames.com (Randy Davis) Newsgroups: sci.geo.satellite-nav Subject: Re: New to GPS - Garmin, Eagle or magellan Date: 22 Nov 1996 00:19:22 GMT Organization: Atari Games Corporation Lines: 181 Message-ID: <572ria$1el@void.agames.com> References: <55e0rd$ho8@news-central.tiac.net> <847902005.32031@dejanews.com> <328CDE5B.3F55@HomeMail.com> <56u08t$a93@sjx-ixn4.ix.netcom.com> NNTP-Posting-Host: gate-ninja.agames.com X-Newsreader: TIN [version 1.2 PL2] In article <56u08t$a93@sjx-ixn4.ix.netcom.com>, Brian P. Oliver (maniacs5@ix.netcom.com) wrote: |The Magellan GPS 2000/3000/4000 units are NOT single channel units - |they are 2-channel units. Maybe not perfect but twice the channels of |a Garmin. Just my observation of a fact. Ok, speaking of facts... From what I understand, the Magellan units also take quit a bit longer to aquire satelites from warm or cold start, which kind of negates at least part of the reason for a two-channel receiver, I would think. The original poster might be interested in the features table posted here a number of months ago by someone else that attempts to put the specs in tabular form for easier comparison, for most of the units available at the time - the list does not include the latest Garmin offerings, but these may be extrapolated fairly easily, since the 45XL ($279) is the 45 external antenna with the 38 software an audible tone you can program, and works off 12 volt power, and the GPS II ($249)is the 45XL without the tone, a different case, a display which you can change orientation, and a couple more buttons. (I don't know if anyone has compiled a new comparison listing). Each unit has different strengths. My decision was swayed against the Magellan units because they had no provision for downloading/uploading log or waypoint data from the unit (and I *do* use this quite a bit). The comparison of aquisition times is telling, and, as I've never yet seen an instance where more than eight satellites were visible, I've never worried about having the ability to track eight satellites on the Garmin versus the Magellan capability of being able to track twelve at the same time. Also, a nice bonus: the screen is larger on the Garmin units, and the batteries supposedly last longer in battery-saver mode. However, if you don't care about interfacing the unit to your PC, and have otherwise different needs, the Magellan units may be more appropriate for you. Randy Davis randy@agames.com Here's the copy I based my Garmin 45XL purchase on... [Reprint of comparison posting:] ------------------------------------------------------------------------------ From: ellerbe Newsgroups: sci.geo.satellite-nav Subject: Re: Receiver Comparison File - Request Date: Wed, 24 Jul 1996 04:57:50 -0700 Here is my second attempt to gather and correlate performance information on the current, widely available GPS handheld offerings. Responses to the first edition were added. Comparison of Handheld GPS Sets ======================================================================== Manufacturer and Model ---------------------- Garmin 38 .............................................................. Trimble Scoutmaster ................................................ | Magellan DLX-10 ................................................ | | Magellan Trailblazer/Meridian XL ........................... | | | Garmin 75 .............................................. | | | | Magellan 3000/4000 ................................. | | | | | Magellan 2000 .................................. | | | | | | Garmin 45 .................................. | | | | | | | Garmin 40 .............................. | | | | | | | | Eagle AccuNav Sport ................ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | FACTS, FIGURES, FEATURES | | | | | | | | | | ----------------------------- --- --- --- --- --- --- --- --- --- --- # of keys and switches 19 10 10 11 11 20 11 24 8 10 Moving map/track plotter yes yes yes no yes yes yes yes yes yes Automatic track log yes yes yes yes yes yes yes ? ? yes Log interval, min ? var var 10 10 var ? ? ? var Paper map plot scaling/projection ? no no no yes no yes ? yes no Graphic steering yes yes yes yes yes yes yes yes ? yes Landmark or waypoint capacity 200 768 768 100 200 250 200 1K 250 768 Track log capacity 500 250 250 na 41 250 ? 400 100 250 # of routes 20 20 20 1 5 10 5 20 10 20 Max legs per route 10 30 30 29 20 20 15 20 10 30 Landmark messages ? no no no yes no yes ? ? no Reversible route/backtrack yes yes yes yes yes yes yes yes ? yes Mark function yes yes yes yes yes yes yes yes ? yes Mark point icons yes no no no no no yes yes ? ? MOB function ? yes yes no yes yes yes yes yes yes Go to function ? no no yes yes yes no yes yes no Point A/N labels with key input yes yes yes yes yes yes yes yes yes yes # of mark point label characters 13 6 6 6 6 6 6 ? ? 6 Automatic leg sequencing ? yes yes yes yes yes yes ? yes yes Local datum selection no yes yes yes yes yes yes yes yes yes Number of datums 1 103 103 12 72 103 72 11 123 106 Local or universal time display ? yes yes yes yes yes yes yes ? yes Static position averaging ? no no no no no no ? yes yes Sunrise/sunset prediction ? yes yes no yes yes yes yes yes yes Lunar prediction ? no no no yes no yes yes yes yes Nearest waypoint search ? yes yes no yes yes yes ? ? yes L/L resolution 0.001 arc minute ? yes yes yes yes yes ? ? ? yes WGS-84 Height to 1 meter ? yes yes yes yes yes yes yes ? yes UTM display output no yes yes yes yes yes yes yes yes yes Other grids no no no no yes yes yes yes yes yes UTM resolution, m na 1 1 1 1 1 ? ? ? 1 NMEA 183 output yes yes yes no yes yes yes yes yes yes Log or waypoint PC download yes yes yes no no yes no yes yes yes Waypoint upload yes yes yes no no yes no yes yes yes PC plan/plot program option yes yes yes no no yes no yes yes yes Parallel receiver channels 5 1 1 2 2 1 2 10 3 1 Satellite visibility display ? yes yes yes yes yes yes yes yes yes Satellite signal strength display yes yes yes yes yes yes yes yes ? yes Satellites tracked simultaneously 12 8 8 12 12 8 12 10 8 8 Geometry achieved, expected error ? yes yes yes yes yes ? ? yes no Ground speed limit, m/s 425 46 46 425 425 46 425 425 ? ? Alarms no no no no no yes yes yes no no Trip odometer ? no no ? ? no ? ? yes yes Use defined display windows yes no no no no no no no no no Remote antenna option yes yes yes no yes yes yes inc yes no Swivelled, folding antenna yes no yes no no yes yes yes no no Integral patch antenna yes yes no yes yes no no no yes yes DGPS ready (corrections port) yes yes yes no yes yes yes yes yes yes Battery saver mode yes yes yes no no yes yes yes yes yes Memory retention battery yes yes yes no no yes no ? ? yes Year Introduced 94 94 94 95 96 92 94 95 94 96 Power draw, watts 1.8 0.7 0.7 0.3 0.3 1.1 1.5 1.0 ? 0.7 Continuous operation time, hr ? 10 10 17 17 6 6 10 6 10 Battery saver operation time, hr ? 20 20 na na 8 ? ? ? 20 Batteries, AA 6 4 4 4 4 4 3 6 4 4 Weight, oz, with batteries 21 10 9 10 10 19 14 30 14 9 Screen size, sq in. 5.1 3.3 3.3 2.5 2.5 3.3 4.6 4.6 3.1 3.3 Low operating temperature -20 -15 -15 -10 -10 -15 -10 -10 -10 ? High operating temperature 70C 70C 70C 60C 60C 70C 60C 60C 60C ? Tracking dynamics, g ? 3 3 2 2 3 2 ? 2 3 Acquisition time, sec, average Reacquire after 1 min dropout 10 20 15 30 30 15 45 15 120 ? Day old almanac, initialized 30 15 15 60 60 15 120 35 120 ? No almanac, no init 900 450 450 180 180 450 900 300 ? 450 Lowest street price, $ 400 270 300 200 250 500 300 600 700 190 Notes : 1. The statement and comparison of the specific waypoint, track log, fix plotting, and mark point facilities of each unit has proved very difficult and is undoubtedly not done justice above. 2. Garmin units have an automatic track log store which is independent of the waypoint store. Marking a point creates a waypoint entry, not a track log item. Magellan land units have a distinct landmark memory that is separate from either route waypoint/leg storage or track log. Comparison of these features has been difficult. 3. Garmin uses a trademarked multiplex scheme. Garmin 38 and 40 will not work on automobile 12 V power. All other units will work on a wide range of DC power. 4. Magellan 2000/3000/4000 have a satellite track status display that does not show Satellite ID numbers. There are indicators on the bottom of the display for signal lock and 2D fix annunciation. The track plot only updates upon display selection and not continuously. 5. 3000 and Meridian are marine oriented. 2000, 4000 and Trailblazer are land oriented. The plain Trailblazer and Meridian have many fewer features than their XL cousins for $50 less and have no satellite status display. 6. The Trimble product is a relative of marine Ensign XL, Geoexplorer and Flightmate, and Scout. The display is not graphic. 7. DLX-10 has a large number of menu driven functions. It is a relative of professional survey units and GIS field terminals and looks like the original 1000 and 5000DX. 8. Eagle is using the Rockwell OEM receiver module, a cut above any of the nonparallel receivers. This receiver very effectively uses the fifth channel in a satellite rover role. The unit has a folding patch antenna and the greatest user definition of screen formats. Both land and marine navigation functions are in this unit and the large screen does provide higher pixel count than the other receivers. Global MapSport is a related product with cartography functions. 9. Acquisition times are taken from data sheets and aren't equivalent between manufacturers. They certainly aren't tested and don't mean much. There is confusion over the use of the terms "cold start" and "warm start". 10. There is an important difference in output port usage between NMEA position reporting and steering output in real time and a one time waypoint download. 11. Each manufacturer has many optional accessory kits intended for each product for PC communication, mounting, antennas, I/O, battery elimination. 12. All have 1 year warranty and backlit LCD displays, battery eliminator option, velocity display, computed Magvar and water resistance. 13. Battery life is quoted for nonrechargeable alkaline cells.