TacLocate

TacLocate is a Geographic Information System (GIS) pocket tool. You can use GPS, WiFi and cell-phone tower signals to find your location, plot a history of locations, analyze data spread, plot direction vectors, explore locations using a world map, convert geographic coordinates among longitude and latitude (DD or DMS), UTM and MGRS unit systems, store location points, and send formatted TXT, CSV and KML data attachments via email, for use in spreadsheets or other map tools.

** Note: TacLocate accuracy is optimized for “tactical” distances from a few meters to a few hundred kilometers. For very long (great-circle) distances, say many hundreds or thousands of kilometers, one should use a different tool.

A few practical uses, which in part drove design of TacLocate, are described below.

Compass Bearing of a Path or Land Feature -- It is sometimes desired to be able to determine a compass bearing along a road or fence-line, or between two points in a field or two corners of a property, when other map-based references are not immediately available. Engaging the "FIT ALL" vector will typically display a stable and repeatable compass direction along a walked path, and better than 1 degree repeatability is typical when walking (or driving) along roads. If location points appear to line-up well along the displayed vector, then one probably has about the best direction estimate one can get with the App. If the points appear to deviate far from the displayed vector, or describe an obviously curved line or multi-segmented line, then the "FIT ALL" vector might not be useful. HOWEVER, it should be noted that the vector result in these cases might still be about right, since the mathematical "fitting" of a line through the data is in fact a good way to estimate a single bearing line that best represents such data. Note that pressing "Clear OLD" can be useful in removing older points that appear Not to be in-line with the "FIT ALL" vector; these points tend to be those recorded while starting onto the path. Also note that the "1ST-to-LAST" vector mode can work better than "FIT ALL" if the points don't seem to describe a straight line at all, and/or if one really just wants the rough bearing from one location to another (and the locations are fairly far apart). The "1ST-to-LAST" mode also shows the distance between the points (vector length).

Route Creation for Other Applications -- In this example we assume one would like to define a series of geographic points along a precise route, using topographic and photographic reference data, for use in another application that requires a series of such points. Using the App in the Map mode, one could pan the map to place the reticle on each point of interest (say road bends and intersections), pressing the "STORE Loc" button for each location to be saved. In the Data mode, one can review and convert the units of each point in the list of locations, or send-out the entire stored list in a CSV- or KML-formatted file attachment, via email, for other applications to import, including direct loading into a spreadsheet.

Coordinate Unit Conversion -- In this example scenario, one has some geographic location coordinates that need to be quickly converted from say LONLAT to UTM units (or vice versa). Using the Map mode, one would first tap the location bar to show the correct starting units for the input coordinates. Then one would zoom into the location of interest by a combination of drag-panning and double-tap zooming to the approximate location of interest. Once close, one would fine tune (press "Fine") the location, focusing on the coordinate values displayed in the location bar. Once the location is set, tapping the location bar will show the input location in the other units of interest. Alternatively, one could also just press "STORE Loc" for each location until all have been entered, and then review/convert each point in the Data mode, or transmit all the stored data, via email, in the standard output files which contain all the stored locations, automatically converted and listed in all the available coordinate units.

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Indoor stationary scatter and Current location in DMS. Indoor stationary scatter and Centroid location in DD.

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1st-to-Last Vector on path, showing bearing & distance. Fitted Vector on path data, showing avearge bearing.

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Path data in a Topographic view, in UTM units. Path data in a Photographic view.

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Path in Topographic view of a "noisily" followed road. Stored "noisy" path (with MGRS readout) ready for email.