GPS Visualizer

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Upload your files

Applies to: all formats

Notes about uploaded files:

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Add SRTM elevation data

Applies to: all formats, including file conversion

GPS Visualizer has access to a copy of NASA's SRTM (Shuttle Radar Topography Mission) elevation data set, as well as the USGS's NED (National Elevation Dataset). If your coordinates do not contain elevation information, enable this option if you want to be able to colorize by altitude or draw an elevation profile. Even if you already have elevation info that was recorded by your GPS, this can still be helpful because GPS devices are not very reliable when it comes to altitude data, and the data can be very "noisy," with ups and downs that shouldn't really be there.

If your data is entirely within the U.S., choose NED or SRTM1 as your data source; it is the highest-resolution available. For the rest of the world, select SRTM3. Unfortunately, data is not available north of 60°N latitude.

NOTE: If you choose to use SRTM elevation data, any GPS altitude readings that were originally in your data will be discarded!

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BG map opacity

Applies to: All formats except Google Earth

If you choose to have a background map, it's a good idea to lighten up the colors in the map -- i.e., make it partially transparent -- so that you can actually see your data on top of it. This control lets you decide exactly how opaque the background will be. 100% will produce an unaltered map, and 0% would make it invisible.

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Background map

Applies to: All formats except Google Earth

Waypoints and tracks are much more useful with a map behind them; this is where you decide which kind of map that will be. For technical and legal reasons, the choices available in Google Maps are not the same as those available in JPEG/PNG/SVG maps; also, in Google Maps, you can change the background view at any time. (Click here for an example map that lists and demonstrates the many Google Map backgrounds that are available.)

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Background map opacity

Applies to: SVG, JPEG/PNG

If you choose to have a background map, it's a good idea to lighten up the colors in the map -- i.e., make it partially transparent -- so that you can actually see your data on top of it. This control lets you decide exactly how opaque the background will be. 100% will produce an unaltered map, and 0% would make it invisible, so it's not even an option. (Values between 30% and 70% typically produce the best results.)

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Border

Applies to: SVG, JPEG/PNG

If you select "yes," a thin black line will be drawn around the edge of your drawing.

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Calculate frequency

Applies to: all formats

If you're using the "data" form, which can colorize or resize points based on fields in your data, you can ask GPS Visualizer to automatically count up your points for you, and you can then use the calculated frequencies to resize or colorize points by "N". If you set this to "automatic," GPS Visualizer will use any and all "location" fields (city, state, ZIP code, etc.) to count your points. If you say "Using a specific field," it will use the field you specify (be sure to type it exactly as it's given in your input data), but be sure to ONLY use location-based fields or the results may be strange.

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Colorize tracks

Applies to: all formats

GPS Visualizer can colorize your tracks according to speed, elevation, or some other unit -- or it can give each track its own color. By default, the minimum value is drawn in red and the maximum is drawn in magenta/violet, with a ROYGBIV spectrum in between; adjust the spectrum settings to use different color values.

Note: if your GPS data file does not include speed, course, or distance information, GPS Visualizer can estimate these measurements; they may not be 100% accurate. (Speed can only be calculated if you have a "time" field, of course).

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Colorize min. & max.

Applies to: all formats

Normally, GPS Visualizer colorizes your map by simply reading the minimum and maximum value contained in your data. If you want to override the upper limit, however, you can do so here. (Any values which are higher than the new maximum will be gray by default, unless you've adjusted the Color of values beyond min. or max. setting.)

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Colorize waypoints

Applies to: all formats

Waypoints can be colorized in the same way that tracks can: from red to purple, based on the minimum and maximum values. Note that if you choose to colorize both tracks and waypoints in the same map, things can get complicated and unpredictable.

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Color of values beyond min. or max.

Applies to: all formats

If you've manually applied a minimum or maximum value to the colorization spectrum, GPS Visualizer has to know what to do with points that lie below the minimum or above the maximum. You can either have those outlying points be gray, or just the closest color available (the minimum point's color for too-low values, the maximum point's color for too-high values).

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Connect segments

Applies to: all formats

If you choose "yes" for "Connect segments," a visible line will be drawn from the end of one track segment to the beginning of the next. If you choose "no" (the default) a line will still be drawn (for continuity purposes), but it will be invisible. Some data formats -- such as GPX and OziExplorer -- actually have ways of defining track segments. For others, however, GPS Visualizer will automatically mark "end of segment" whenever it encounters a subsequent trackpoint that has no GPS fix. Therefore, if you are seeing very spotty data (i.e., you were in a forest or surrounded by buildings), you may want to turn on "Connect segments" so that your track does not show up as a series of small, incoherent dots.

Note: This setting has no effect if you use "Complete paths" drawing mode; in that case, every point is always connected.)

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Discard outliers

Applies to: all formats

Some waypoint/position files have waypoints in them that you either forgot about or didn't know were there to begin with (the latter is especially true, it seems, of files dumped from Garmin receivers); these outlying points can cause problems when, for instance, you're trying to plot points in Ireland, but there's one point from Brazil that causes your map to span the entire Atlantic Ocean!

The solution is to ask GPS Visualizer to discard any waypoints which are very distant from the rest of your points. The "outlyingness" is calculated via a Z-score; this is a measure of how many standard deviations lie between a given number and the mean of the sample it came from.

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Draw Forerunner laps

Applies to: all formats

Garmin Forerunner Logbook files contain "Laps"; a better name might be "splits," but that's beside the point. At any rate, you can choose whether or not these lap markers will be displayed on the map as waypoints. If you choose to display them, and you have "Waypoint descriptions" enabled, the descriptions will include the duration, length, and average speed of each lap.

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Drawing mode

Applies to: SVG, JPEG/PNG

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Google Earth altitude mode

Applies to: Google Earth

Google Earth assigns one of two "altitude modes" to tracks: they are either "absolute" or "clamped to ground." For almost anything other than a flight, you should choose "clamped to ground"; otherwise, some of your track might actually disappear beneath the terrain, where you won't be able to see it. For airplane/paraglider/hangglider flights, however, "absolute" will show your track suspended in the air where it belongs.

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Google Earth document name

Applies to: Google Earth

If you type something here, it will be used as the name of the folder that appears in the "My Placemarks" section of Google Earth. If you don't supply a document name, GPS Visualizer will try to construct a logical name based on your input files.

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Google Earth file type

Applies to: Google Earth

Google Earth supports two kinds of placemark files: KML (uncompressed) and KMZ (ZIP compressed). The obvious advantage of compressed files is that they're smaller and will download faster; the only advantage to uncompressed files is that you wouldn't have to unzip them before editing them, if you needed to do so.

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Google Earth initial view

Applies to: Google Earth

By default, when you open a Google Earth file that was created by GPS Visualizer, you will be looking straight down from a sufficient altitude to show all your data, and north will be at the top of your screen. If you want to change any of the defaults, feel free. Note that "tilt" is the number of degrees from vertical, and "range" is related to altitude -- if you leave tilt at zero (zenith), range is altitude.

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Google Earth time stamps

Applies to: Google Earth

In Google Earth, placemarks can have a timestamp attached to them that can be used for various interesting animation effects. Select this option to have GPS Visualizer add time stamps to your track data (assuming your data contains time information). Be aware that when your file first opens in the Google Earth application, you may see only a small segment of your track, depending on your previous settings.

NOTE: when you choose "by track" (the default) or "none" for track colorization, your track is drawn in Google Earth as a "polyline": a long string of points defined only by latitude, longitude, and altitude. In that case, you can't assign a time to each individual point -- unless you choose to have the track duplicated as waypoints using the "trackpoints as waypoints" option.

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Google Earth waypoint marker style

Applies to: Google Earth

Google Earth waypoint markers can have any kind of icon attached to them; a few of the most generic-looking built-in ones are provided as choices. If you want another option in the menu.

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Google Maps background type

Applies to: Google Maps

Google Maps can have three different types of backgrounds: map (a political map with street-level detail and labels on almost everything), satellite (whatever imagery Google can dredge up for that area), and hybrid (the map type overlaid on the satellite imagery, but with fewer labels and less detail at wider views). Whichever you pick, you can always change it while looking at the map later.

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Google Maps custom HTML styles

Applies to: Google Maps

A "power user" feature: You can tell your map to follow certain HTML stylesheet rules. You can supply either the URL of a .css file, or raw CSS style declarations. Note that some of Google's v3 styles are difficult to override, so you may need to add "!important" to your custom declarations. And to be safe, always add #gmap_div at the beginning of each custom declaration, like so:

#gmap_div .gv_label { color:black; background:white; }

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Google Maps custom JavaScript

Applies to: Google Maps

A "power user" feature: You can tell a GPS Visualizer Google Map to run some custom JavaScript code, either before or after the commands that set up your map and draw all the waypoints and/or tracks. You can enter the URL of a .js file, or simply paste in a chunk of JS commands. If you don't have the syntax exactly right, your entire map may fail to load, so be careful.

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Google Maps opacity control

Applies to: Google Maps

By default, GPS Visualizer will add a drop-down menu that allows you to alter the opacity of the background map at any time; change this to "no" if you want the opacity control to be unchangeable.

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Google Maps scale bars

Applies to: Google Maps

By default, GPS Visualizer will request that Google add metric and U.S. scale bars to your map; change this to "no" if you don't want them.

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Google Maps waypoint marker style

Applies to: Google Maps

Google Maps waypoint markers are somewhat more complicated than those in Google Earth; there is not a set of hundreds of built-icons to choose from, and if you use your own custom icons, you can't assign arbitrary colors to the icons once they're loaded.

However, GPS Visualizer hosts a few sets of icons that you can use in your Google Maps, in any color or opacity.

"pins" [pin]
"Google pins" [google]
"Google pins (no dot)" [googleblank]
"Google mini-markers" [googlemini]
"small circles" [circle]
"small squares" [square]
"small triangles" [triangle]
"small diamonds" [diamond]
"crosses" [cross]
"small stars" [star]
"airports" [airport]
"cameras" [camera]
"very large circles" [blankcircle] -- this one is only useful when the points will be resized, e.g. on the "data" form.

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Google Maps waypoint labels

Applies to: Google Maps

By default, GPS Visualizer does not put waypoint labels on your Google Map, although you can "mouse-over" the waypoint markers to see a "tooltip" with the name of the point. If you select "permanent labels," the names of the points will be drawn to the right of the points -- and can be printed, which is very helpful -- but be aware that these labels cannot be moved or hidden.

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GPX/CSV routepoints

Applies to: all formats

GPX and plain-text (e.g., CSV) files can contain "routes" in addition to tracks and waypoints. Usually, a route is a simply list of existing waypoints. GPS Visualizer can handle these routes in a variety of ways:

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GPX speed in km/h

Applies to: all formats

GPX files are supposed to use m/s as the unit for the <speed> tag, if speed info is present. Unfortunately, some software developers have ignored the specifications and used kilometers per hour instead of meters per second in their GPX output functions. If you know you have one of these faulty files (or if you notice that all your speeds are off by a factor of 3.6), check this box to tell GPS Visualizer that your file uses km/h.

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Hue 1, Hue 2, Spectrum direction

Applies to: all formats

By default, GPS Visualizer colorizes your data so that the lowest values are red, middle values are yellow and green, and the highest values are magenta (i.e., a ROYGBIV spectrum), but if you don't like that setup, you can specify different colors for the minimum ("Hue 1") and maximum ("Hue 2") values. Because our eyes perceive hue in a continuous "color circle," hues are given as degrees: red=0°, yellow=60°, green=120°, blue=240°, magenta=300°, etc.

The "Spectrum direction" parameter (which is actually "colorize_reverse" in the guts of the form) controls which direction the colors go around the wheel. The default is "up," which means red would go through yellow and green on its way to blue; if you change the direction to "down," the colors will go from red through magenta and violet to reach blue.

Example: Let's say you're making a map of the concentration of a pollutant in the atmosphere, so you want low values to be green, average values to be yellow, and high values to be red to indicate too much pollution. Set Hue 1 to 120° or 135° (green) and set Hue 2 to 0° (red), and be sure to set the spectrum direction to "down"; if you leave it on "up," mid-range values will be blue instead of yellow. You could even set Hue 2 to magenta, but you would still keep the direction as "down."

Custom spectrum files

The hue and spectrum direction parameters give you quite a bit of control over the color palette that GPS Visualizer uses when you choose to colorize your maps or profiles. But if you need even more control, you can supply the URL of a graphic that defines the EXACT color palette that will be used.

A custom spectrum-definition image should be a JPEG or PNG, of any (reasonable) size. Only the pixels in the first row of the image will be used to define the color palette; everything below the first row will be ignored.

For example: here's an image that would cause colorization to resemble that found in classic relief maps, with lower elevations showing up as dark green, middle elevations trending toward yellow and brown, and the highest as white (light blue has been substituted for white, for visibility's sake).

Or, if you wanted your map data to be colorized using only three colors at equal intervals with no gradient between them, you could use a very simple graphic like this:

For countless examples of spectrums/palettes, see colourlovers.com/palettes. (If you find one you like on that site, click on the spectrum's page and then copy one of the "Get this Palette Image" links.)

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Legend placement

Applies to: SVG, JPEG/PNG, Google Maps

If you choose to have your tracks colorized, you'll probably want GPS Visualizer to put a legend on your map that tells you which colors represent which speeds/elevations; in SVGs, JPEGs, and PNGs, the legend can appear in any of the four corners of your drawing. (In Google Maps, it will be in the upper right, but you can move it if you want.) If you choose colorization by track, the legend will show the names of the tracks in the appropriate colors, and in SVGs or Google Maps, clicking on a track's name will show or hide it.

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Legend steps

Applies to: SVG, JPEG/PNG, Google Maps

The legend is just a list of values colorized using the same colors as the track; you can decide how many values to list. (You must have at least two steps, because the minimum and maximum will always be shown.) This parameter is ignored in "by track" colorization.

Note: If you choose a colorization parameter such as "satellites," where only whole number values are allowed, you may get weird values in the legend because the number of steps will not "line up" with the number of possible values.

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Lightness & saturation

Applies to: all formats

You can alter the overriding properties of the colorization spectrum with these two controls. Note that if you set either one too low, you may as well turn off colorization completely, as it will be hard to see the difference between a very dark red and a very dark blue. It's recommended to keep the saturation at 100% and turn the lightness down to 60% or 80% if you think the tracks are too bright and you want them to show up better against the background. Also, you may want to choose a lower lightness value if you are colorizing by track, because the yellows can be hard to see.

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Line width

Applies to: all formats

This is simply the thickness, in pixels, of the tracks.

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Map boundaries

Applies to: all formats

By default, the bounds of your map will be determined by the geographic extent of your data. But if you want to override the default area -- making the coverage area larger or smaller, or consistent with another map -- you can enter a "bounding box" here. A bounding box is simply four numbers separated by commas; the first number is the southern edge, then the western edge, then north, then east -- or you can think of it as the SW corner followed by the NE corner. (For example, a bounding box for the continental U.S. would be 24,-128,52,-64.) All numbers must be decimal degrees, so coordinates in the southern and western hemispheres are negative.

Note: When making a Google Map or Google Earth file, any waypoints/markers outside the boundaries will be deleted.

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Margin

Applies to: SVG, JPEG/PNG

Your data will be plotted in an area equal to the width and height of your map minus twice the specified margin. If your map includes a legend or title, they will be drawn near the edge of the map, not the edge of the track area, so if the legend or title is overlapping your track, try increasing the margin.

Example: If you set the width to 600 and the margin to 40, the entire map will be 600 pixels wide but your data will only fill an area 520 pixels wide.

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Max. number of points per track

Applies to: all formats

Very long tracks in Google Maps can slow down your Web browser, which is one reason the "Maximum number of points per track" option is there; another reason would be to reduce the track during conversion to GPX format, so that your GPS unit will accept the output file. The number of points in the track is reduced (using GPSBabel) by an intelligent algorithm that removes points from straighter segments while preserving more points in areas where they're more necessary.

Click here to read a complete tutorial about track smoothing.

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Merge tracks

Applies to: all formats

This option causes all tracks to be combined as segments in a single track, in the order they were uploaded. If you want to erase the segment boundaries too, set the "Connect segments" option to "yes." Note that each track's description and other meta-info will be discarded.

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Output format

Applies to: all formats

The most popular choices these days are Google Maps or Google Earth files; these are interactive and very flexible, but they don't travel well (unless you take a screenshot).

If you want a "flat" map, you can create a JPEG or PNG; any browser can view them with no outside help, but the output is static and unchangeable.

And then there's SVG... originally, GPS Visualizer only drew maps in SVG format, which have the advantage of being built out of scalable vectors; however, they are not universally supported and the code is infrequently updated.

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Preserve track/waypoint attributes

Applies to: all formats

Some files that you upload to GPS Visualizer might already have their own colors, symbols, line widths, etc., applied to the tracks and waypoints contained in the file. This is especially common with KML files, where every line or marker has a "style" applied to it. And Garmin files (GPX or .gdb) frequently have specific symbols attached to their waypoints.

Whenever possible, GPS Visualizer will try to preserve the attributes that were originally present in your data. However, if you want to override the appearance of your tracks and waypoints using GPS Visualizer's icons or a new colorization scheme, select "NO" in the menu called "Preserve colors and widths" (in the track options) or "Preserve waypoint colors and symbols" (in the waypoint options).

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Profile divisions

Applies to: SVG, JPEG/PNG

Normally, this specifies how many divisions GPS Visualizer will draw, using vertical or horizontal gridlines, to mark off the values on your X- or Y-axis, respectively. However, if you enter "auto" here, lines will be drawn in the logical locations; for instance, a 53-km track's distance axis would have divisions at 10, 20, 30, 40, and 50.

Example: If you enter "4" in the "Y divisions" box, five horizontal lines will be drawn, dividing the graph into four equal slices. If you enter "1," lines will only be drawn at the minimum and maximum points. If you enter "0," no lines will be drawn at all.

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Profile margin

Applies to: SVG, JPEG/PNG

The specified margin, in pixels, will be added to the top, bottom, left, and right of the area defined by the "profile width" and "profile height" variables. If your map includes a title or gridline labels, they will be drawn near the edge of the margin, not the edge of the graph area, so if they're overlapping your graph, try increasing the margin.

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Profile width & height

Applies to: SVG, JPEG/PNG

These controls the width and height, in pixels, of the data that will be graphed. Note that whatever value you specify for the "margin" will be added to the profile on all sides.

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Profile X- and Y-axis

Applies to: SVG, JPEG/PNG

You can draw a profile using almost any measurements as the horizontal and vertical axes; the top and bottom of the axis are defined by your tracks' minimum and maximum values in that measurement. "Distance" is a special case, in that it is calculated by GPS Visualizer; the other measurements are stored in the GPS data -- and please note that distance is only an estimate!

Note: if you want, you can choose a colorization mode that is not the same as either of the axes; in this way, you can actually plot three different parameters on the same graph!

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Profile X/Y min./max.

Applies to: all formats

If you don't specify minimum and maximum values for the axes of your profile, GPS Visualizer will automatically calculate them based on your data. But if you want to override the min. and max., enter new values here. You do not need to supply units: if it's an elevation profile in U.S. units, your numbers will be interpreted as feet; if it's a speed graph in metric units, GPS Visualizer will assume you meant km/h; and so on and so forth. Note that any values which fall outside your specified range will still be drawn; they'll just appear to be "off-screen."

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Remote data URL

Applies to: all formats

Some of the input forms give you the option to enter a URL from which GPS Visualizer will pluck the coordinate data. So far, this only works in a few limited situations.

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Remove all tracks

Applies to: all formats

This option removes ALL tracks (and/or polygons) from your input data, leaving only the waypoints.

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Resize data; Min. & Max. waypoint radius

Applies to: all formats

This allows you to have your waypoints resized based on a parameter of your choice. Note that if you set the minimum size to zero, your points will be compared on a scale that starts at zero, not at your minimum point -- and the sizes of the circles will be assigned based on the square root of your data. So if your smallest data point has a non-zero value but you want it to be miniscule, set the minimum to 1 or 0.5, not 0.

Example: If your quantifiable data ranges from 10 to 20, and you set the min & max radius to 0 px & 12 px, the "20" point will have a radius of 12 px, but the "10" will not be 0 px; it will have a radius of about 8.5 px (it's not simply half of the maximum because they're proportional by area; 8.5 is the square root of half of the square of 12). On the other hand, if your data ranges from 10 to 20 and you set the min & max radius to 1 px & 12 px, the "10" point will indeed get the minimum radius of 1 px.

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Reverse track points

Applies to: all formats

When drawing a profile or converting data to plain text or GPX, the trackpoints will be output in reverse order. When making a map (in any format), reversing the tracks will change the direction in which tickmarks point. In JPEG or SVG drawings, the track's label will appear at the "end" of the track instead of the beginning, if track names are turned on.

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Scale length

Applies to: SVG, JPEG/PNG

For SVG & JPEG/PNG drawings only. Note that the scale length is calculated based on the longer side of your drawing, and it is also drawn on the longer side.

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Show waypoints

Applies to: all formats

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Single-point map width

Applies to: all formats

If your data consists of a single waypoint, GPS Visualizer doesn't know how large your map should be. The number you enter will be interpreted as kilometers unless you type "mi" or "miles" to indicate a figure in miles.

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Synthesize description/name/label/folder

Applies to: all formats

Use this field to have GPS Visualizer build a "name", "description", "label", or "folder" field for points that don't already have one. For example, if your data has columns labeled "x", "y", and "z", you could enter this into the description synthesis box: coordinates = {latitude}, {longitude}<br>x = {x}<br> y = {y}<br> z = {z} -- this would cause each bit of info to go on its own line, thanks to the HTML <br> (line break) tags. If you're creating Google Earth files or Google Maps, there's no limit to how much stuff you can load into a description; just insert existing field names by surrounding them in {curly brackets}, and include any HTML tags you want.

Note 1: any existing "desc" field you may have supplied will be overwritten, although you can use it in the new description by including {desc}; this might be useful to, for example, quickly apply a style or color to all descriptions. (This applies to names and labels as well.)

Note 2: the "synthesize label" feature is only used to put permanent labels on markers in a Google Map; it has no effect on Google Earth files or JPEG/PNG maps.

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Text size

Applies to: SVG, JPEG/PNG

The value (in pixels) that you specify here will set the size of the legend, scale, track names, and waypoint names; in addition, the title (if present) will be 1.5 times this size, and any track/waypoint descriptions will be 3/4 of this size.

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Tickmark interval

Applies to: all formats

You can choose to have tickmarks placed along your tracks at a given interval, to mark your progress. You would usually a distance here; e.g., "10 mi" or "1 km". (If you don't supply a unit, it will be assumed that you mean kilometers.) However, you can also supply a time interval, if your file contains time information in a supported format: enter "s" as the unit for seconds elapsed from the start, or "min" as the unit to see the actual time printed on the map.

Please note that the distance traveled is only an approximation, and it will very likely be a larger number than your GPS receiver tells you, because every point is used in the calculations.

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Time offset

Applies to: all formats

Sometimes your GPS data contains time stamps that are in a time zone different from your own -- usually GMT. Enter your time zone here, in hours (for example, U.S. Pacific time is -8 and Central European time is +1), and GPS Visualizer will try to compensate.

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Title

Applies to: SVG, JPEG/PNG

If you want a title at the top of your drawing, type it here. (For Google Maps, you can easily add a title later by simply editing the HTML.)

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Track descriptions

Applies to: SVG, JPEG/PNG

If you select "yes," track descriptions will be displayed under the track names.

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Track hue default

Applies to: all formats

If you don't colorize your tracks, this color will be used -- unless your track data file has a color specified in it.

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Track names

Applies to: SVG, JPEG/PNG

If you select "yes," and if your map is in a format that supports it, a text label will appear at the beginning of the track with the name of the track. If a track does not have a name defined, the file name (minus the suffix) is used as the track name.

Note: if you choose "by track" colorization, you probably don't need track names; it might be simpler to include a legend that shows which colors belong to which tracks.

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Track opacity default

Applies to: all formats

Most map formats allow you to make your tracks less than 100% opaque, so that a little bit of the background shows through. If you choose a value less than about 70%, your tracks will be hard to see.

If you set the track opacity to 0%, the tracks will not be drawn, but they will be used to calculate the parameters of the map. If you want to suppress the tracks altogether, use the "Remove all tracks" option.

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Trackpoint distance threshold

Applies to: all formats

GPS units often record more points than you need them to, leading to jagged tracks and "blobs" that look like balls of string on the map. GPS Visualizer can smooth out your track by only plotting points that are at least a certain distance from the previous plotted point. If you don't supply a distance unit for the trackpoint distance threshold, meters are assumed.

Click here to read a complete tutorial about track smoothing.

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Trackpoints as waypoints

Applies to: all formats

Typically, a track will simply be drawn as a line. If you select the "Draw trackpoints as waypoints" option, each trackpoint will also become a waypoint that can be clicked on to get more information about that point. (This actually works in all output formats, but is most practical in Google Earth. In Google Maps, it's potentially useful but problematic because displaying markers in Google Maps is so slow.)

If you choose the "custom template" option, you must supply a "template" for the names and/or descriptions of the points, with field names in {curly brackets}. It works just like the "synthesize description" feature for waypoints.

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Units

Applies to: all formats

Choose "metric" if you want distances and elevations to be output in meters/kilometers; choose "U.S." for feet/miles. This only affects output features (legends, trackpoints-as-waypoints, etc.), not input.

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VMG target waypoint

Applies to: all formats

If you select Velocity Made Good as one of your output parameters (e.g., track colorization or a profile axis), you need to specify a point that will be used as the "goal" for the VMG calculation. You can supply a coordinate pair, or the exact name of a waypoint in your file. If you don't supply a VMG point, the last trackpoint of the last track will be used.

If your track had multiple goals that changed throughout the trip, you'll need to upload the legs as separate tracks with different VMG target points.

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Waypoint color default

Applies to: all formats

You can assign individual colors to each of your waypoints (if your input data file format supports that sort of thing), but this parameter sets the default for any points that don't have a color specified. In Google Maps, the default is usually set to a bright color like red; in other types, black or black-and-white will be the default "uncolored" state.

You can use any HTML color you want, but here's the list that appears in the "default waypoint color" menu on the Google Maps form:

   
Google default,
   
aqua,
   
black,
   
blue,
   
brown,
   
cyan,
   
fuchsia,
   
gray,
   
green,
   
lime,
   
magenta,
   
maroon,
   
navy,
   
olive,
   
orange,
   
pink,
   
purple,
   
red,
   
silver,
   
tan,
   
teal,
   
violet,
   
white,
&
   
yellow.

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Waypoint descriptions

Applies to: all formats

If you select "yes," any waypoint descriptions will be displayed under the waypoint names. (If you choose not to have the waypoint names displayed, the descriptions will generally be displayed in place of the labels.)

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Waypoint display padding

Applies to: Google Maps & Google Earth

This works like the "margin" setting in SVG or JPEG/PNG maps: it is a buffer zone around your tracks that determines which waypoints will be displayed (see Show waypoints for more info). In Google Maps and Google Earth, it's a percentage rather than a number of pixels because the maps can be panned and zoomed, making pixel measurements somewhat irrelevant.

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Waypoint fill opacity

Applies to: SVG, JPEG/PNG

This is the opacity, from 0 to 100, of the center of your waypoints.

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Waypoint outline opacity

Applies to: all formats

In SVG or JPEG/PNG maps, this is the opacity, from 0 to 100, of the line around the circumeference of your waypoints. (Unfortunately, in JPEG & PNG maps, values between 1% and 99% are ignored; if you don't set it to 0%, it will be 100%.) In Google Maps or Google Earth KML files, this parameter is used for the overall opacity of the marker icon.

Note: In Google Maps, only GPS Visualizer's built-in icons can be made semi-transparent; icons from elsewhere will always be 100% opaque.

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Waypoint names

Applies to: all formats

If you select "yes," a text label will appear next to each waypoint with the name of the waypoint (if one is present).

Note: To suppress the display of the name on some points but not others, leave "Show waypoint names" on "yes," but give the nameless points a name of "-" (a single hyphen/dash, no quotes); if you leave the name blank, GPS Visualizer will try to build a name from the coordinates or address information.

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Waypoint radius (unresized)

Applies to: SVG, JPEG/PNG

This simply controls the size, in pixels, of the circles that indicate waypoints on your map. If you have chosen to resize your waypoints according to some data field, any points that don't contain data for that field will get this default.

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WEP colors

Applies to: all formats

This only applies to wireless internet log files ("wardriving"). If you turn on WEP colors, unsecured access points will appear in green while WEP-enabled ones will be red.

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Width & Height

Applies to: all formats

This is the width and height, in pixels, of the window in which the map will appear. The map will be zoomed in/out an appropriate amount to show all of your data.

If you set either the height or the width to "auto" (the default), a sensible value will be chosen based on the shape of your data, but it will never be more than the fixed measurement. In other words, a map with height set to auto will never have a vertical orientation; if you have data that is mostly north-south and you want a "skinny" map, set the height to a specific size and change the width to auto.

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WiFi file mode

Applies to: all formats

Raw NetStumbler and WiFiFoFum log files contain a long series of data points for each base station you detected, plus a "summary" data point for each station. (Raw WiFiFoFum logs doin't contain the summary point, but GPS Visualizer calculates an estimated center point for you.) You can choose to display only the longer tracks, only the summary points, or both. Be aware that if you do both, it can get very messy if you have a large log file.

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Zoom control

Applies to: Google Maps

By default, GPS Visualizer will request that Google add a pan/zoom control to your map; you can turn it off, but that will make navigation more difficult, so be careful.

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