|
| Home | Guest - Not logged in | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
» Register
» Login
Gear Reviews
Documents
Tools
» Contact
|
Reviews > Navigation and Map Gear > GPS > Magellan SporTrak Topo 2003 > Shane Steinkamp > Field Report
The Magellan SporTrak Topo GPS unit (Model # 980616-39) is manufactured by: Thales Navigation. WEB: www.thalesnavigation.com or www.magellangps.com YEAR OF MANUFACTURE: 2003 (Date Code 4403 = Week
Of November 5, 2003) A very detailed description and listing of specifications, as well as a Glossary of Terms, is provided in the Magellan SporTrak Topo Initial Report. FIELD TEST LOCATIONS My Magellan SporTrak Topo GPS unit has seen a lot of use. I have carried it through eight states (Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and North Carolina) and collected over 3,600 miles (5,700 km) of telemetry using the unit. I have used it for highway travel, trail walking, bushwhacking, mapmaking, boating, geocaching and to locate National Geodetic Survey Markers. Weather and terrain was variable though a broad range of conditions, and specific conditions are referenced in the body of this report where appropriate. OPENING NOTES The basic operation was covered in the Initial Report, and some of the basic operation will be reviewed in this report as well. Before I get into all the gory details, I want to state that I have some issues with the Magellan SporTrak Topo, and at least one could be a serious issue in the context of backpacking. None-the-less, if I had to purchase a GPS unit for backpacking use tomorrow, I would purchase a Magellan SporTrak Topo. So, the negative aspects of the unit are detailed for the sake of accuracy and honesty, but I have been very pleased with the unit overall and I would recommend it. ERGONOMICS AND THE PHYSICAL UNIT The unit fits well in the hand, feels comfortable to hold, and the buttons are arranged in an ergonomically friendly way. I have no issues with the physical unit itself. The case has been very durable, and even though I have tried to take care of it, I have dropped and kicked it a few times. The unit has suffered no damage during the Field Testing phase. The LCD screen provides very easy viewing, even at an angle. The graphics and text are very clean, sharp, and easy to see. At night, with the backlight on, and the unit at arm's length, the data fields are easily visible, but the data field descriptions do wash out a little. TURNING IT ON The SporTrak Topo is powered on by pressing the small red power button. An audible beep is heard and the unit comes on. The welcome screen appears for a few seconds, then a copyright notice if a detail map has been uploaded, then a warning screen that cautions, "WARNING All data is provided for reference. You assume all responsibility when using this device. Press ENTER to agree." If ENTER is not pressed, the unit powers off after a few seconds. At first all of this was rather annoying. Now I hit the power button and then hit the ENTER button four times and just bypass the initial screens out of habit. POWER CONSUMPTION I have kept detailed notes on battery life, and I can confidently say that with no use of the backlight, the Magellan SporTrak Topo will run for almost 13 hours continuously on one set of alkaline batteries. If the unit is not used continuously, and the batteries allowed to rest between uses, about 14 hours can be expected. I have used nothing but fresh Energizer brand batteries during the testing period. I did not use the unit under cold conditions, but it is commonly known that cold with shorten battery life. I have prepared the following chart that shows the time, battery meter display, and time remaining.
THE BACKLIGHT The functionality of the backlight was covered in the Initial Report. I find that the LOW mode is totally adequate in any level of darkness that I have experienced. Use of the backlight severely cuts battery life. Under no circumstances did I find that the Magellan SporTrak Topo would run longer than four hours continuously on a fresh set of batteries while the backlight was on. While night hiking I do not use the backlight at all, but simply illuminate the unit with my headlamp. At this point, I only use the backlight in the car while driving at night. DATA WEALTH & DATA HARMONY In the Initial Report I talked about Data Harmony, Data Wealth, and Data Interface. I posed the simple premise: "What is the purpose and function of a GPS unit? Simply stated, the purpose and function of a GPS unit is to provide the user with a position fix. A GPS unit is a servant that answers the question, "Where am I?" The evaluation of the SporTrak Topo, then, will be foremost an evaluation of how well the unit performs its basic function - location of position - under various conditions." I am pleased to report that under many various conditions, the SporTrak performed exactly as I expected - and in fact surpassed my expectations in many respects. The Magellan SporTrak Topo GPS unit is a very excellent servant that works very hard to answer the question, "Where am I?" It will locate its position quickly, accurately, and report that position in an easy to understand way. It is not my usual habit to grade or rank gear that I test, but the Magellan SporTrak Topo gets an A+ for its ability to locate itself - and me - under conditions where other GPS units that I saw were lost. If you have a GPS with a patch antenna, you should try a unit with a Quad Helix like the SporTrak and compare the results. The difference is astonishing. THE NAVIGATION SCREENS According to the manual, there are nine user configurable Navigation Screens. These are: Status, Map, Compass, Large Data, Position 1, Position 2, Road, Strip Compass, and Speedometer. All of the Navigation Screens are customizable to some extent. The Navigation Screens were pictured in the Initial Report. The Navigation Screens are accessed by pressing the NAVIGATION button. From any screen other than a Navigation Screen, pressing the NAVIGATION button will display the last navigation screen viewed. If the NAVIGATION button is pressed while performing data inputs, the inputs will not be saved. Pressing the NAVIGATION button sequentially scrolls through the Navigation Screens in the above order, while pressing the CANCEL button in navigation mode will scroll in reverse order: The best way to understand the screens is to understand that there are only three kinds of screens. These are the Satellite Status Screen, several Primary Data/Navigational Display Screens, and The Map Screen. There are also several Secondary Data Display Screens that are not accessed as Navigation screens, but through the menu. SATELLITE STATUS SCREEN The Satellite Status Screen provides a graphical display of the satellites in view and which ones are being used to compute the navigation data. The bar graph shows the relative signal strength being received for each satellite. At the bottom of the display is an indication of the battery life remaining. When using external power, this is indicated in place of the battery meter. The Satellite Status Screen is the only screen that isn't actually valuable for navigation. It is useful in determining the signal strength of individual satellites, the availability of WAAS satellites, and the health of the composite signal that allows computation of the unit's position. PRIMARY DATA/NAVIGATION DISPLAY SCREENS
There are seven Primary Data/Navigation Display Screens. These are Compass, Large Data, Position 1, Position 2, Road, Strip Compass, and Speedometer. These screens all share a common functionality and a common purpose: to display navigational data to the user. Each of these screens is composed of two or more individual data display fields and four of them incorporate graphical representations of analog devices (Compass, Road, Strip Compass, and Speedometer). The individual data display fields can be customized by the user on each screen to display the data most useful to the user. These Customizable Data Displays are very easy to set, and the user can select from 13 different data options. These are listed and defined here.
COMPASS SCREEN The Compass Screen literally displays a graphical compass. At the very top of the screen, the destination waypoint name is given. The lower half of the Compass Screen displays the heading and course using the graphical compass, and it also displays the relative positions of the sun, the moon, and the GOTO destination, if programmed, around the rim of the compass. The upper half of the screen displays four customizable navigational data blocks. The default display shows bearing, heading, distance, and speed. These four data windows can be changed to display any one of 13 data options as defined above. For backpacking, the Compass Screen is one of the most useful of the Navigation Screens. I found myself turning to it again and again while walking. The graphical display is very accurate and easy to understand. It isn't always easy, however, to actually take a bearing off that digital compass. You can't sight down it like you can with a lensatic compass, and you can't lay it on a map like you can with a navigational compass. Still, I found it easy enough to follow it while walking, and every bit as accurate as my floating needle compass. It's good enough for orienteering and backpacking. LARGE DATA SCREEN The Large Data screen is similar to the Compass screen but here the compass has been removed to allow for very large display of four navigation data windows. These four data fields can be changed to display any one of 13 data options as defined above. The Large Data display is very useful while traveling in a vehicle, as the large display is easy to see at a distance up to twice arm's length. POSITION SCREEN The Position Screen is actually two screens that can be flipped back and forth by pressing the CURSOR KEY left and right. The Position screens 1 and 2 display the present position using the coordinate systems that have been selected in Setup. This screen shows the basic position, time and satellite information. In addition, two data fields can be changed to display any one of 13 data options as defined above. At the very bottom of this screen, a resetable Trip Odometer is displayed. Unfortunately, the Trip Odometer is faulty. When traveling at speeds above 5 mph (8 kph), the Odometer is always a little short. (Uploading a track reveals the true distance.) When traveling at speeds below 5 mph (8 kph), the Odometer is grossly short. The Odometer is, in my opinion, severely faulty and therefore worthless. The Position Screen was only useful to me when I wanted to know my coordinates for plotting on a paper map, but at that point it is the only screen needed. Pressing the Menu button from the Position Screen gives several options available only from the Position Screen. The Coordinate System selection allows the user to select the Primary and Secondary coordinate systems displayed on the Position Screen. The Map Datum selection allows the user to select the Primary and Secondary datum. A customizable, user defined datum can also be accessed and setup from here, but there are no instructions and I can't figure out what it means despite trying to educate myself. The Elevation Mode allows the user to select 2D (3 satellites minimum) or 3D (4 satellites minimum) resolution. 3D resolution allows computation of elevation while 2D does not. The Projection selection allows the user to 'project' a waypoint from the current position, any user waypoint, any city, highway, airport, waterway, or park in the database to any distance and bearing away from that point. If you wanted to plot a point five miles due south, for instance, this is easy to do using the Projection screen. The Reset Trip selection resets the trip odometer. THE ROAD SCREEN The Road screen presents a route as if traveling on a road. When a turn is coming up, the road will graphically display the turn and the direction. Waypoint and destination icons are displayed relative to the current position as they come into view. Above the road is a compass that displays the heading and above that are four customizable data fields. These four data fields can be changed to display any one of 13 data options as defined above. The Road Screen displays the active leg of a route as a graphical representation of a road. This means that the road is always a straight line from the previous waypoint to the next waypoint, and once the next waypoint is reached, the Road Screen will display a turn in the direction of the next waypoint. Of course, roads, trails, and even bushwhacked routes are rarely straight lines from one point to another. (Navigating across water, and across great distances, is a different story.) Any deviation from the straight line course causes the Road Screen's road to move off the edge of the screen and be lost. The various zoom levels are confusing, inconsistent, and not explained in the manual. I attempted very precise placement of waypoints at crossroads and landmarks, but even so the Road Screen was nearly useless because the Road Screen's graphical road suffers from the same plotting errors as the Map Screen. (See the Map Screen section for more information.) Essentially, if you plot a route using the MapSend Topo software that follows a real road, then you drive on that real road, the Road Screen's road will usually be off the screen because of plotting errors even if the road is perfectly straight. I have ceased to use the road screen, and I have disabled it entirely. If it actually worked it would be a very cool feature. Unfortunately, I think that the data load for an actual graphical representation of the road you are traveling on would be prohibitively high for a handheld unit given the state of technology today. THE SPEEDOMETER SCREEN The Speedometer Screen shows a graphical representation of an analog speedometer, four customizable data fields, and a trip odometer. These four data fields can be changed to display any one of 13 data options as defined above. The trip odometer is flawed, as noted in the Position Screen section above. The speedometer will change scale based on the rate of travel. The average speed is graphically displayed as a dark band along the top edge of the speedometer. Since speed and average speed are both selectable in the customizable data fields that can be displayed on any of the data screens, I didn't use the Speedometer Screen much except as a novelty - but it works and works well. THE STRIP COMPASS SCREEN The Strip Compass Screen shows a graphical strip compass and six customizable data fields. These six data fields can be changed to display any one of 13 data options defined above. I very frequently used the Strip Compass Screen because this is the screen that displays the most data wealth at one time. While the strip compass is handy, I would like to eliminate it and have two more data fields in its place. That could actually be another screen - the Small Data Screen - similar to the Large Data Screen. Hopefully Magellan will allow for this in a future release. OTHER SCREENS The above descriptions only cover the Navigation Screens. There are several other useful screens, including Sun and Moon Data, Hunting and Fishing Times, as well as a wide array of menus that activate various functions, customize the displays, and allow the unit to be tailored to the individual user. It is obvious that a very large amount of thought went into the software design of the Magellan SporTrak Topo. I have compiled some comments on the various Special Screens. SUN AND MOON DATA SCREEN
I like the idea that sun and moon data are at my fingertips. I always made sun and moon charts for every day I would be out, and now I just use the SporTrak. This data can be very important in places like the desert for calculating move and rest times, as well as simply being aware of how much time you have before the sun goes down. It's also useful for photography, when you want to know when the sunrise or moonrise will happen so that you can get set up for it. The SporTrak makes this charting unnecessary. Unfortunately, the execution of the idea leaves a little something to be desired, but the function is still useful if you understand the issues. I've created a chart to help with my explanation. It is important to understand the apparent motion of the moon in order to appreciate the chart. The moon orbits the Earth every 27.3 days. However, because the Earth also moves in that time, it takes an additional two days to "catch up" to where it started. So the moon's orbit is actually 29.5 days. The Earth also revolves on its axis every 24 hours (one full day). The moon rises in the east and sets in the west, and, like the sun, its exact position and apparent path depend on the time of the year. The moon's time of rising varies in a different way from that of the sun. If the moon rises at 1:00 P.M. one night, the next night it will rise at about 1:50 P.M., the next about 2:40 P.M., and so on; after about one month (50 min * 28 days = 1400 min = 24 hours) it will rise at 1:00 P.M. again. The moon rises, on the average, 50 minutes later each day (or night) and moonrise can be at any time of day or night. The path the moon takes across the sky depends on both the time of year (like the sun's path) and its phase. The new (or nearly new) moon is always on (nearly) the same path as the sun, so it is low in the sky in winter, high in the summer. The full (or nearly full) moon is opposite the sun in the sky (rises at sunset, sets at sunrise), so it is high in winter, low in summer. Full moonlight appears brighter in the winter than in the summer because the full moon is higher in the sky. The length of time the moon is up depends on where it rises, just like the length of time the sun is up (the daylight hours) depends on where it rises. The apparent position of the moon in the sky depends on where you are on the earth's surface. As you move around the earth, you observe the moon in exactly the same way you observe the sun: move north, the moon seems lower; move toward the equator, and the moon seems higher. Got that? Good. Now, on to the chart. This is a snapshot in time to illustrate the issues I discovered. I give the SporTrak's data first, and the data chart I usually make for comparison. Data not provided by the SporTrak is left blank. The data was taken on 9 April 2004 and 10 April 2004 on Santa Rosa Island in Santa Rosa County Florida, USA. Coordinates: 30 22.453N 086 54.073W
This is the data that I usually want to know when hiking. As you can see, the SporTrak does not provide all of this data, but transit times and twilight times are easy enough to calculate from the data given. The issue arises at certain times on certain dates where the moonrise is close to midnight. As you can see, the SporTrak reports that moonrise on the 9th is 12:20 AM and moonset is at 9:27 AM. This is false. In reality, as you can see from my chart - as verified by actual observation - the moon that set at 9:27 AM ON THE 9th actually rose at 11:12 PM on the 8th. The SporTrak's moonrise data for the 9th actually belongs on the 10th, because the moon did indeed rise at 12:20 AM on the 10th. Similarly, the moonrise time on the 10th is incorrect, as it belongs to the 11th. This time shift is not constant, but seems to only happen periodically when the moon rises near to midnight. I did not spend enough time - and didn't collect enough data - to reverse engineer the software, so I can't postulate on the cause of the error. It is also possible to use projection to calculate Sun and Moon Data - as well as Hunting and Fishing Data - by selecting different dates and different location. To test the projection feature, we need to know how fast the earth is rotating at our coordinates. To calculate this we need to know that the earth is rotating at about 1070 mph (1722 kph) at the equator. Then we do some math. COS(LATTITUDE) * MPH @ EQUATOR (1070 mph (1722 kph)) COS(30.380556) * 1070 or 1722 0.862685 * 1070 = 923.07 mi = 1,485.53 km So, if we project a point 923.07 mi (1,485.53 km) due west, we should come up with one hour differences in the sunrise/sunset times for any given day. Testing proves that the projection works, and the unit even adjusts for time zones. The same issue with moonrise times also affects projection.
The Hunting and Fishing Times Screen can be accessed through the menu, or by pressing the cursor button left or right while in the Sun and Moon Data Screen. Two editable fields at the top of the screen allow the user to change the position and the date for the data shown. If the position is changed, the times shown will be local times for that position. I have to admit that I didn't use the Hunting and Fishing Times Screen at all. I have looked at it, and I know that it's a function of tide times and a few other things, but I hunt and fish when I have need to and when opportunities present themselves. This is very rare at this stage in my life. I would much rather have had the Tide Times Screen that comes with the Magellan Marine package than the Hunting and Fishing Screen.
The Vertical Profile Screen shows the vertical profile (elevation profile) that the user selects. The selections are Track History (where you have been), Path Check (where you are going), and Route (which displays the entire active route). This may seem passably interesting on the surface, but the Vertical Profile Screen is kind of amazing. Take Track History for instance, displayed here at the right. You can see that the scope is from zero to 200 ft, and that the entire track is 236 miles (379.8 km). The minimum elevation was 0 ft (0 m), and the maximum elevation was 187 ft (57 m). The pointer is showing a point at 13 ft (3.96 m). It shows that I was at that position at 12:21:03 PM on 12 APR 2004. I can scroll left or right and see each trackpoint along the way like this. Better yet, the zoom buttons work too. I can zoom into the elevation profile at any point I like. You can do this not just for where you've been, but you can project various routes and see what the way ahead is like as well. Unfortunately, the Vertical Profile Screen uses the map data to calculate all of this, so the shifting and plotting issues described below apply to the Vertical Profile Screen and cause inaccuracies. THE MAP SCREEN The Map Screen shows the unit's position in the form of a triangular direction icon graphically on a map, but when the CURSOR KEY is pressed the triangular direction icon is replaced by a crosshair icon. This crosshair icon can be moved around the screen and used to scroll across the basemap. On the surface, that's useful for seeing what lies a little beyond the edge of the displayed map, but the ZOOM buttons work in this mode as well. It is possible to visit far off places and zoom in to walk a 'virtual hike', and even set waypoints, before you even get close to a location. This also allows the map to be referenced for planning and other things. I used this feature extensively during the Field Test period and found it very useful. At the bottom of the Map Screen is the scale for the map, which is about 1/4 of the width of the screen. The scales are described in the Initial Report. Data can also be displayed at the bottom of the map screen, or can be hidden to reveal more of the map. The data selections are Street Info, Horizontal Profile, Terrain Projection, and Two Customizable Data Fields. The two data fields can be changed to display any one of 13 data options as defined above. The Street Info display will show either the street name or feature name that you are traveling upon or passing through, or in the Cursor Mode will show the street name or feature name that the cursor is pointing to. The Horizontal Profile mode a graphical representation of the horizon at the bottom of the map screen. The distance to the displayed horizontal profile is equal to the map scale selected with the zoom buttons. In this mode there is a line projected out from the present position icon to a shorter perpendicular line. The intersection of the two lines indicates the location on the map where the horizon is being computed. The Terrain Projection is a simpler version of the Vertical Profile Screen. This mode graphically displays the elevation directly ahead of the unit in a straight line from the current position to the top of the Map Screen. This provides instantaneous information on what terrain elevations are directly in the direction of travel. Unfortunately, both the Horizontal Profile and Terrain Projection modes suffer from the same shifting and plotting issues described below, so they are not always entirely accurate. Pressing the Menu button when the Map Screen is displayed gives several menu options specific to the Map Screen. Hide/Show Map Info selection will hide or show the data display on the Map Screen. Hiding this data will reveal a little more of the map. The Map Setup selection reveals the Map Setup screen with two tabs. The Format tab allows the user to select Orientation, Detail, Track Mode, and Primary Usage. The Display tab allows the user to select the kinds of things that are displayed on the Map Screen. The Orientation options are North Up, Course Up, and Track Up. North Up means that north is always at the top of the map screen. Course Up means that the current course to a destination is always at the top of the map screen. (A GOTO must be set.) Track Up means that the direction of travel is at the top of the map screen. I like the Track Up option, because the map orients itself to the direction of travel and scrolls as I move. I will admit that it took some getting used to, because I normally orient paper maps with north at the top even when not traveling due north. The Detail options are Highest, High, Medium, and Low. This controls how much detail is displayed on the Map Screen. I usually used High or Highest, but this does slow the Map Screen down some, and it can become very cluttered at low zoom levels. The Track Mode options are Off, Auto, Auto Detailed, 2.0 MI, 1.0 MI, 0.5 MI, 0.2 MI, 0.05 MI, 0.01 MI. This controls how trackpoints are created and is explained in the manual. For mapmaking I used Auto Detailed while walking, and then turned the Track Mode off if I wanted to explore a side trail that I didn't want to map. When I returned to the main trail at the precise point where I turned the tracking off, I would turn it back on and continue mapping. The Primary Usage options are Marine and Land. In Land mode, land is light and water is dark. Selecting Marine reverses this display. The Display Tab allows the user to show or hide the following items: Waypoints, Track Lines, Topo Lines, Position-Destination Line, Depart-Destination Line, Arch, Area, Bar, Basin, Beach, Bend, Bridge, Campgrounds, Cape, Cliff, Falls, Flat, Forest, Gap, Gut, Harbor, Levee, Locale, Oilfield, Range, Rapids, Reserve, Ridge, Spring, Summit, Swamp, Tunnel, Valley. DATA SYNTHESIS As noted in the Initial Report, the GPS unit is a radio receiver for a special kind of technological symphony. It does not function by itself. The satellites sing and dance, ground stations set the tempo, and the SporTrak translates this data synthesis into the music of navigation and provides a melody that a rambler may follow wherever his heart desires. There is a definite distinction between the music and the melody, and I want to restate the distinction between data wealth and the Map Screen, because the Map Screen represents a different element from the raw data entirely. (The music and the melody, remember?) Data is something that you can use anywhere. If the SporTrak did not have a built in mapping feature, it would still be very useful. Maps could still be made, and navigation would still be possible and definitely very accurate using properly notated paper maps. The synthesis would be complete, and in fact the synthesis is complete - the unit does indeed fulfill all its basic functions and the map works. DATA INTERFACE - THE MAP AS A METAPHOR The Magellan SporTrak Topo provides a level of functionality above simply providing data wealth by translating that data into graphical outputs in the form of on screen maps, elevation profiles, track profiles, and terrain projections. The Magellan SporTrak Topo not only completes the synthesis, it does so in a very dynamic way in real time. The unit not only tells you where you are, it shows you. It is, in a very real way, a magic map. It can show you where you are, where you have been, where you want to go, the surrounding terrain, and how steep or easy your way was and will be. The map can remember important places and lead you back to them. The map can tell you about places that you have never been before and lead you to those as well. All of this is very dependent, however, on how accurate the map is, and The Map Screen is both my favorite feature and my biggest disappointment. The father of general semantics, Alford Korzybski stated, "A map is not the territory it represents, but if correct, it has a similar structure to the territory, which accounts for its usefulness". While the basemaps and MapSend Topo software provide a fair level of detail, and are acceptably accurate, the synthesis between the data wealth and the map is faulty. There are two separate faults: 1) The map is flawed, and 2) the position plotting on the screen map itself is flawed. In reality, only the first might be true, but I am unsure for the reasons stated below. In all honesty and fairness, I might be nit-picking, but I will lay out my findings and let the reader decide. USING THE BASEMAPS - THE BRAIN BEHIND THE MAGIC MAP
There are actually two basemaps inside the Magellan SporTrak Topo, but they are overlaid and appear to be one map. Unfortunately, there is a shift in the overlay that causes inaccuracies in the map in some places. It is necessary to discuss each basemap in turn, and then discuss the marriage of the two in order to get a complete picture. The first map is an 8 MB roads basemap of cities, highways, railroads, airports, waterways and parks. This basemap contains major roads for most major cities, and the interstate system. The second map is a 100 MB topographic basemap. This basemap contains navigable waterways, major contour lines, and elevation information. The roads basemap is satisfactorily detailed, and the MapSend Topo roadmaps are very detailed, but both are slightly dated - and that is actually to be expected. I have covered the MapSend Topo Software in a separate report. I did find several roads, the vast majority being new construction, that were not noted on the maps. This is not troubling to me. Any map is actually outdated by the time it is printed. What is more troubling is that I found some instances of roads, railroads, and other features that do not exist in reality and have never existed. In row B of the above illustration, I have documented an instance of navigating with the unit using the basemaps. I took the SporTrak with me to Houston, Texas and on the return home Interstate 10 was blocked by a major accident. Consulting the basemap allowed me to navigate around the accident and lose just minutes instead of hours. A similar situation played out in Atlanta, Georgia, and I saved at least two hours because of the SporTrak unit. The maps are useful, but they are flawed. At low zoom levels no flaws are apparent. However, at higher zoom levels the position indicator is rarely on the road as I drive along. In fact, at high zoom levels, several errors are apparent. Referencing the table above: A-1: Interstate 10 through Jefferson Parish, Louisiana. The west bound lane obviously doesn't do that... A-2: Earhart Expressway off ramp in Jefferson Louisiana. The track is off - and hence the reported position on the map - by 422 ft (128.6 m) It should be noted that the unit is reporting a nearly perfect position when plotted on a USGS paper map, but the overlay with the maps in the unit and the maps in the Mapsend Topo product is obviously imperfect. A-3: Clear Springs Mississippi. While bushwhacking, I set a waypoint to the road using the map screen. And, as evidenced by the track, missed the road by 175 ft (53 m). Plotting the coordinates on a USGS paper map proves that the SporTrak Topo is reporting the coordinates correctly, but they are not being translated to the onboard map accurately. B-3: Interstate 10 across Mobile Bay in Alabama. The taken waypoint, and associated track, puts me 264 ft off the bridge and into the bay. If I were navigating the bay in a boat in a heavy fog, 264 ft is obviously a dangerous error. At the time, the unit was reporting 3 meter accuracy - and plotting the waypoint on a paper map proves that the coordinates are on the bridge, but they aren't plotted properly on the electronic map.
Here is one example that is typical. Santa Rosa Island in Florida. Observe Santa Rosa Blvd coming in from the left, and then stopping. The pickup point is 34 ft (10.4 m) due south, and the road continues. Obviously the road doesn't do that. The road is contiguous. If you examine the bottom of the image, you will see a shoreline shift that is identical to the road shift - 34 ft (10.4 m). This shift does not exist and is an artifact of (I'm pretty sure) two maps being 'stitched' together. Moving 22 mi (35.4 km) due west along the map reveals another similar shift. It's quite easy to find them by following roads. There are places where these errors seem to be cumulative, causing the error to be as great as 0.19 mi (0.31 km) in the worst case I experienced. Admittedly these errors are small, and when navigating over a distance of several miles, they have little impact. While backpacking, however, these small errors can be very important. It can mean the difference between finding a water source in the dark and not finding it, for instance. These small errors are legion, and must be allowed for when using the map screen to navigate over relatively short distances. I missed a road by 422 ft (129 m) in easy terrain and this was no big deal. 422 ft (129 m) in bad terrain - and bad weather - could put me over a cliff. Bottom line: I do not trust the map at small scales, and sometimes it fails to be a useful reference. Magellan's explanation for this is found in the Appendix of the manual: "Position on map is not exactly on the road. It could be caused by distance shifts to the map. Use map data for reference and do not rely completely on it." I don't know what 'distance shifts to the map' means exactly, but if it means that the maps simply aren't as good as they might be, then I'll accept that. The topo map is similarly flawed, but again the differences are small. The topo maps are not very detailed, and I have included a side by side comparison of a USGS map (on the left) and the MapSend Topo map (on the right). I have found many inaccuracies in the contour lines, and to make matters worse, the contour scale seems to change - and the contour lines shift - when the zoom level is changed on the map screen. As one example, the thin gray line that comes down the center of the MapSend Topo map and runs right through the middle of the lake is a 300 ft (90 m) contour line. There is obviously no such contour. In the Santa Rosa Island image above, the contour line visible as a faint gray line likewise does not exist. Santa Rosa Island is a 'desert island' and is mostly flat with a few dunes. To make matters worse, the overlay of the topo map over the roads map is usually off, causing points of interest and other landmark features to be shown on the map where they obviously are not. Travel across the southeastern United States proved to me that this is not a local problem. I have found the topo maps useful in only a basic way, and I do not entirely trust them. As I said above, it is very possible that I'm nit-picking, but I don't find the maps accurate for small scale navigation - anything less than about a mile (1.6 km). Of course the question arises, "Well, what WOULD be satisfactory?" I don't honestly know. I do appreciate that you can't squeeze cheese out of a rock, and that nothing - least of all a map - is perfect. The unit is capable of resolving a position down to an accuracy of three meters. In my opinion, it would be really nice if the map plotting was accurate to within that distance as well. I still like the map screen, and I still use it, but I don't trust it, and I make allowances for that lack of trust. I wouldn't use it as my sole navigation tool in heavy terrain to be certain, and it isn't good enough to navigate off road flawlessly in places I have never been before. The unit does not replace my paper maps at all, but it does augment them considerably, and the mapping feature makes it easier to mark the paper maps because it will at least put me in the ballpark of where I need to make my marks. Someone more knowledgeable about all this than I is probably saying, "Well, of course, you idiot! That's what it's for!", and maybe it is. It isn't, however, what I expected when I got the unit based on Magellan's claims - but I will readily admit that my expectations were probably higher than the current state of technology can provide in a cost effective way. These errors aside, I am very pleased with the functionality of the Map Screen and I would not buy a GPS unit without a Map Screen. Maybe maps are for suckers, but I'm one of the suckers... IN THE FIELD - DESCRIPTIONS OF USE I have used the Magellan SporTrak Topo through eight states (Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and North Carolina) and collected over 3,600 miles (5,700 km) of telemetry using the unit. I have used it for highway travel, trail walking, bushwhacking, mapmaking, boating, geocaching and to locate National Geodetic Survey Markers. Geocaching and NGSM hunting are not necessarily related to backpacking and therefore beyond the scope of this report. In brief, I found every cache and every NGS marker that I went looking for. The unit never failed to put me within just a few ft of the cache or marker, and on more than one occasion, led me right on top of it. I was very impressed by this. Two weeks after receiving it, my first trip with the SporTrak unit was from New Orleans, Louisiana, USA, to Greensboro, North Carolina, USA - a round trip distance of approximately 1,800 mi (2,900 km). I very carefully set waypoints along the Interstate and then detailed my route, including a turn by turn route to my destination once I reached Greensboro. I mounted the unit on my dashboard using the car mount and plugged it into the cigarette lighter using the external power cord. I left the paper maps at home in the spirit of experimentation. Throughout the trip I experienced excellent reception and never failed to receive a WAAS signal. I was delighted that the unit showed the next city, which I had set as a waypoint, along the way and provided information such as the ETE, ETA, Distance, and many others covered above. There was a definite psychological satisfaction in knowing exactly how far it was and how long it would take to reach the next restroom. I did note that rest areas were not marked on either the basemaps or the MapSend Topo maps and I really wish they would be. Upon arriving in Greensboro and picking up the detailed turn-by-turn route I quickly proved that billions of dollars worth of satellites and a state of the art GPS receiver were no guarantee against getting lost. We arrived in Greensboro very late that evening and I made a wrong turn. Unfortunately I could not correct the error immediately and wound up several miles off course. Trusting that I could use the unit to navigate, I abandoned my preset route and struck off into unknown territory. This proved to me beyond a shadow of a doubt that the map is not the territory. Greensboro is a spider web nightmare of roads and streets - even worse than New Orleans, if that's possible. Often it is impossible to go back the way you came, and you have to go around for a certain distance in order to get back to where you were. After an hour of unsuccessfully attempting to get the unit to tell me how to go, misunderstanding what it was telling me, and aggravating my wife in the process - I gave up and called for directions. Examining the situation after a good night's sleep with the benefit of the uploaded track in the MapSend Topo software I realized several things. One, no amount of technology will be useful if the operator is at fault. Two, the Map Screen doesn't quite show enough of a map to be able to navigate over any large distance in a city of illogical streets. Getting the larger picture provided by a paper map is sometimes useful if not absolutely essential. Now that I have much more experience with the unit, I am confident that I could now find my way using the unit with little difficulty. At that time, however, I didn't have enough experience with it to allow for the shortcomings of both the unit and the user. I had only been to Greensboro, North Carolina on one previous occasion and the city was totally unfamiliar to me. Using the SporTrak unit I was able to ride with friends and make maps of key destinations and roadways. Within two days I could mount the unit to the dashboard and select the "STORE" route and the unit would direct me to the store and back again. I made routes for the YMCA, the gas station, the mall, the drugstore, and several others. These routes quickly became unnecessary as I learned my way around, but did prove to me that the unit was capable of building useful routes. On the way home from Greensboro, we took a different route and stopped to visit friend and fellow tester Coy Starnes and his family in Grant, Alabama. Having previously plotted many waypoints into a route, the unit brought me right to Grant, and although Coy and his lovely wife met us in town and allowed us to follow them back to the house, I am confident that we would have found it even in the dark of night with the SporTrak. Wandering around the next day to Piney Branch Falls and then down into a fabulous holler to see some falls along Honeycomb Creek, the unit performed admirably. Even the map cooperated, showing us actually in Honeycomb Creek when we were - although it did miss Piney Branch Falls by 105 ft (32 m) Two weeks after returning from Greensboro, we took a trip to Houston, Texas, USA, to visit family. Again I loaded the detail maps out of MapSend Topo and used it while driving. I noticed that even small stock ponds were shown on the map. I had no trouble with the route, and although I had never been to Granny's new house, the unit led us right to it with no problem. It was during this trip that I noticed that the Odometer was grossly short on mileage. Further testing proved that it was useless. It never shows the correct distance traveled, and is usually more than ten percent short. Before Blackadder sets off on his journey, Lord Melchett, one of the Queen's courtiers hands him a map and says, "The foremost cartographers of the land have prepared this for you. It's a map of the area that you'll be traversing." The map is completely blank. "They'd be very grateful if you could just fill it in as you go along."
A week later I used the SporTrak to navigate my way in the dark through Homochitto National Forest in Mississippi to the Clear Springs Campground and the Talley Creek Trail trailhead. By this time I was very much used to the shifts and plotting errors in the map and was able to compensate for them perfectly. I arrived without incident and used the SporTrak to find an old campsite in the dark. It was on continuously in order to make a map of the Talley Trail, and even under heavy tree cover I always received a good signal - and under most conditions had WAAS as well. As you can see from the above map, my little mapping project went quite well. I was able to mark brides, trail splits, campsites, mile markers, road crossings, and several other important features. I found the topo maps to be quite basic, but the road maps were impressive. Even forest service roads were marked accurately. Despite walking over ten miles (16 km) - as verified by the uploaded track - the Odometer showed less than five miles (8 km). I don't even look at it any more. In early April I took a trip to Navarre Beach, Florida. Our parents have a modest beach house on the Gulf of Mexico and I thought it would be an excellent opportunity to use the SporTrak. I did a lot of verification work with the sunrise/sunset times and found them to be accurate within one minute when allowing for the issues mentioned above. I also took my usual walk down the beach, past the beach houses and into Gulf Islands National Beach - also known as Opal Beach - to find a secluded spot to have a proper swim. I've always wondered how far my walk took me, and a few times I tried to distance it out on the road, but the road is too far away to get a decent idea of where I walk so I brought the SporTrak with me. By this time I knew that the odometer was useless, so I devised a trick to bypass the odometer entirely. Since the shoreline is mostly a straight line, I walked out onto the beach and set a waypoint at my current position called "START". I then immediately set a GOTO to the START waypoint and started walking down the beach away from the START point. The unit then displayed the distance to the 'destination' I had set. Since I was walking away, the distance increased. When I got to the end of my walk, I knew exactly how far I was from the beach house. Even better, by walking back towards the beach house for just a few steps the unit reported how long it would take me to return (ETE). This allowed me to figure out exactly how much time I could spend in paradise before having to begin my return walk in order to make it back for dinner. Unfortunately, the unit does not have an alarm for the time, but it would have been nice to have had one so that the unit could have told me when it was time to go home without having to check it every so often.
As you can see from the chart, the walk was a little under 3 miles (4.82 km). Over the course of the first 1.5 miles (2.41 km), the unit reported various elevations. I was walking along the shoreline of the Gulf of Mexico, so my elevation should always have been between zero and 5 ft (1.5 m). Obviously this is not the case. The second 1.5 miles (2.41 km) is my walk back. As you can see, the unit reported the elevation accurately until the very end of the walk, when the error spiked at 161 ft (49 m). I remained on the island and on the ground at sea level the whole time. While at the beach I discovered a new game: GPS Dancing. GPS Dancing is made possible because of the unit's averaging algorithms. When you first turn the unit on, it gets a satellite fix and reports a position. The longer the unit stays on, the more accurate the position becomes because the more data it has collected and the longer it has had to integrate the WAAS signal into the averaging. In order to enjoy this new game, follow these steps: Turn the unit on. Wait for a signal lock. As soon as you get a signal lock, MARK a waypoint at your location, then set a GOTO to that waypoint. Your distance to the waypoint will be zero, but that will change. If you're looking at the EPE and Distance data, you'll see that the EPE gets smaller over time, but your reported position will shift a little bit and cause the Distance to be some positive number. The dance is accomplished by trying to get the Distance data back to zero by moving around. I discovered this game quite by accident, and my wife wanted to know what the hell I was doing. (She often wants to know that...) I told her, "Dancing with the SporTrak." She just shook her head... I have used the SporTrak much more than this, but time and space do not allow me to elaborate any further. I think I have covered all the important points. NOTES ON SPECIFICATIONS, FEATURES, AND CLAIMS I have several comments on the various specifications listed in the Initial Report. Position Update Rate (per second) - 1 I have found this rate to be true and accurate, but under various conditions - like traveling at high rates of speed while looking at a highly zoomed map image - the unit will lag slightly while the map is being refreshed. Time to First Fix: Cold -
< 2 Minutes I have found these numbers to be greatly conservative. Under even mediocre conditions, the unit locks a signal very quickly. When a signal is lost - such as driving through a tunnel - the unit will re-attain a position fix within three seconds of exiting the tunnel. I find the unit's tenacity at finding and holding satellite signals very impressive. From time to time I have found that the unit will not find any satellites at all when first turned on, and I will have to cycle the power off and then back on to reactivate the scan. I am unsure what causes this, but it has only happened about five times since I have owned the unit. Minimum/Maximum Altitude - Sea Level / 17,500 M (57415 ft) The documentation indicates that the unit will not function below sea level. Being in New Orleans - parts of which are several yards (several m) below sea level - I can report that the unit will report an elevation of zero when below sea level. Antenna - Quadrifilar Helix (Internal only) I find that the antenna receives its best signal when the unit is held straight up and down. The Quadrifilar Helix antenna in the SporTrak Topo receives a better signal than any other GPS unit I compared it to. I find the unit's tenacity at finding and holding satellite signals very impressive. Even under moderate to heavy tree cover I was always able to obtain a 3D fix - and usually I had excellent signal levels on four or five satellites. Only under exceptionally poor conditions did I ever not receive a WAAS signal in the areas of operation I detailed above. Construction - Rubber Armored Impact Resistant PlasticThe Magellan SporTrak Topo has been dropped, kicked, and generally abused more than I would have liked. It has never complained, the case shows little sign of wear or abuse, and the unit has sustained no damage during the Field Testing phase.
Horizontal Accuracy (m) -
< 7 m (23 ft) I have found the accuracy of the Magellan SporTrak Topo to be exceptional. I have used it for geocaching and to locate National Geodetic Survey Markers. As described in the main body of this report, the unit seemed to become more accurate the longer it remained active. The EPE as reported by the unit is usually between 10 and 30 ft (3 and 9 m), averaging towards the lower end of the scale, and I find the EPE reading to be conservative. The unit will usually put me to within 6 or 7 ft (1.8 or 2.1 m) of any coordinate target. Vertical Accuracy (m RMS) - 10 m (32.8 ft) I have found that the Vertical Accuracy figure is not as good as reported. I would say that the Vertical Accuracy is within 24 m (80 ft). Please see the main body of this report for more details. Velocity (knots RMS) - 0.1The average accuracy of the velocity is within 0.1 knots (0.12 mph, 0.19 km/h). I have found this to be true as long as the velocity was greater than about 5 mph (4.34 knots/h, 8 kph). When moving at less than that speed, the average accuracy of the velocity could vary by as much as 0.2 knots (0.24 mph, 0.38 kph). Receiver WAAS/EGNOS Enabled - Yes WAAS/EGNOS can be disabled. See the Undocumented Menu below for details. In the areas of operation detailed above - largely in the Southeastern United States, I am almost always able to receive a WAAS signal under normal operating conditions.
Waterproof (IEC-529 IPX7 Standard) -
Yes. Despite the fact that the Magellan SporTrak Topo made several water landings - even in salt water - I have never experienced any leakage. The unit does float, which makes retrieval much easier. Operating Temp Min (F/C) -
14F/-10C I think that this figure is very important. Backpackers are quite likely to experience the minimum operating temperature in some areas. I did not experience the minimum or maximum temperatures over the course of the test period, and I do not expect to at this point. Waypoints - 500 A waypoint is a point along the way. I've never managed to make 500 of them. Routes - 20A route is often referred to as a GOTO route. It is simply a plot from one point to another. The simplest route has a starting point and a single destination point: I am here and I want to GO TO there. All that is required to create a GOTO route is having the destination waypoint saved in memory. This waypoint can be one that you have saved earlier (which is stored in your User Waypoint List) or any of the landmarks that come with the SporTrak in its built-in database. Whether the route is a simple GOTO or a more complex multileg route, it needs stored waypoints to use as its starting and destination point. If it is a multileg route, then each leg must have terminating waypoints. Routes created in the unit are limited to 48 waypoints. Routes created in the MapSend Topo software are limited to 30 waypoints. Trackpoints - 2000Trackpoints are saved by the SporTrack along the route of travel. Essentially, Trackpoints are automatic temporary Waypoints. I have never managed to make 2000 of them. Grids - Latitude/Longitude, UTM, OSGB, MGRS, Finnish, German, Swedish, French, Irish, Swiss, USNG, User GridDatums - 75 User-defined Datums - 1 A Datum is a model, defined by a set of parameters and control points that is used to accurately define the three-dimensional shape of the Earth. Datums are the basis for planar coordinate systems - in other words, map grids. The manual is sorely lacking in any description or instruction on the use of the Datums, and it gives no instruction on the input of the User-defined Datum. I will endeavor to educate myself during the Long-Term Test period and report more on this function in the Long-Term Report if I can. Data Input - Yes - Via 9 pin serial cable. I do not have a 9 pin serial connector on my IBM R32 laptop, but it does have USB ports. I purchased an IOGEAR USB 9 Pin Serial Adapter and it has worked flawlessly (under Microsoft Windows XP Professional) with the SporTrak unit.
Optional accessories also sold separately -
Belt Clip carrying case: black, green or blue The MapSend Topo Software was included with the Magellan SporTrak Topo unit. There are other versions of the MapSend Software available for specific applications. I cover the details of the MapSend Topo Software in a separate report. I purchased a vehicle mounting bracket; the one with suction cups. The other vehicle mounting bracket requires holes to be drilled in the dash board. I wish Magellan made the bean-bag base holder like Garmin does. The suction cup mounting bracket bounces a lot and I finally brought it down the windshield so that the unit rests on the dashboard and doesn't bounce. I purchased a 12 volt power cord for use in the car. This mates with the mounting bracket and has been great in the car because its definitely cheaper in the long run than using batteries. I purchased a belt clip carrying case, and a belt loop carrying case. The belt loop carrying case is a bit snug for the unit, but I have used and enjoyed both cases. Alarms - Arrival, Anchor, XTE, GPSThe Alarms all function as advertised. There is an additional alarm that is not noted in the manual; the EXTERNAL POWER LOST alarm, which is activated when the unit is removed from external power. The backlight activates when the alarm activates. MapSend Topo Software"The full version CD-ROM of MapSend Topo’s highly-detailed 3D topographic maps is included with your SporTrak Topo. Giving you the option of a higher level of detail in your topo mapping. Topography derived from the U.S. Government Digital Elevation Model (DEM), provides elevation details for every location on the map." Expandable"Easily expand your mapping capability by downloading other detailed maps from Magellan MapSend software titles to 16 MB of available memory. It is possible to expand the maps using the built in memory, but it is not possible to expand the memory." 16 MB is plenty. I have been very happy with the memory capacity of the SporTrak unit. Full-featured navigation"Nine customizable graphic navigation screens include a map, compass and speedometer with text readouts of heading, bearing, speed, direction, ETA, and more. Choose from 12 built-in coordinate systems and 76 datums including Latitude/Longitude, Universal Transverse Mercator, and Military Grid Reference System (MGRS)." Address search "With the addition of street-level mapping using optional Magellan MapSend software, you can search addresses and let SporTrak Topo guide you to your destination." This feature works, and works well. It's quite amazing, actually. Built-in help database "The SporTrak Topo is intuitive, easy-to-use, and all the major functions are described in step-by-step instructions." The help database is very basic, but functional. It cannot be said to replace the manual. The Magellan SporTrak Topo has an undocumented menu that allows access to several functions. This is evidently a menu that the user is not normally intended to access, but there are several useful things about it, so I have detailed it here. All of this was learned through trial and error, and I have been informed that these codes can really screw up the unit if you do it wrong, so follow the astronaut's code when playing with these: "When in doubt, don't." I have noted the dangerous ones. The 'secret' menu can be accessed one of two ways. Either hold the Navigation and GOTO buttons and press power, or with the unit on and in the main menu, press right-left-right-left on the Cursor button. The codes are as follows: (Codes that seem do nothing are not noted.) 00 Version Information I will continue to evaluate the Magellan SporTrak Topo during the Long-Term Test period. I will continue to educate myself in order to report more advanced features of the unit. I have several hikes planned, and will move forward with several mapping projects during this time. I am really very happy with the Magellan SporTrak Topo unit, even though the 'new toy' novelty has worn off. I find it to be a very useful navigational aid. THINGS I LIKE 1. Light THINGS I DON'T LIKE 1. Map errors. THINGS I WOULD LIKE THE UNIT TO DO I found myself wanting several things. One, when the unit is off, I would like the screen to function as a simple clock. This would take minimal battery power and allow me to leave my watch at home. I would also like a time alarm, and possibly even a stopwatch function. Given the technology inherent in the device, I am unsure why such simple features were left out. I would also like a tidal chart - just some high tide/low tide times would be nice. I would like another navigation screen with nothing but data fields on it. Eight or ten would fit. It would be the Small Data Screen - similar to the Large Data Screen. ADDITIONAL RESOURCES I have prepared a list of additional resources for those wishing to learn more about Global Positioning Technology (GPS) and other fun stuff to do with GPS units that is beyond the scope of this report. This is hosted on my own hiking website and are not a part of this report. *** Thank you for your time. Shane Steinkamp Read more reviews of Magellan gear Read more gear reviews by Shane Steinkamp Reviews > Navigation and Map Gear > GPS > Magellan SporTrak Topo 2003 > Shane Steinkamp > Field Report | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Sun and Moon Data Screen can be accessed through the
menu, or by pressing the cursor button left or right while in the Hunting
and Fishing Times Screen. It shows sunrise, sunset, moonrise, and
moonset times. It also graphically shows the phase of the
moon. Two editable fields at the top of the screen allow the user to
change the position and the date for the data shown. If the position
is changed, the times shown will be local times for that position.
HUNTING AND FISHING TIMES SCREEN
VERTICAL PROFILE SCREEN
I have a
theory to explain this, and having collected and studied quite a lot of telemetry, I
think I'm right. No large map is a single map. Large maps are
made up of smaller maps, and the basemaps in the SporTrak are no
exception. Where the maps 'stitch' together, inaccuracies occur.
There is an almost predictable pattern at times.
Here
is the uploaded track of my walk. As you can see, I started at the
east most point, traveled about 1.5 miles (2.41 km) west, then took the
same route upon my return - simply walking the shoreline.
Uploading this track into the MapSend Topo software allows us to examine
the elevation data. That's what the graph is below the
image. I should note that the unit was reporting an EPE of less
than 20 ft (6 m) and receiving a WAAS signal for the entire time
period. Skies were clear.