Using Streets & Trips to Generate Waypoints For an Arc Filter to Find Caches Along a Route in GSAK



One of the most frequent requests of geocachers has been how to easily create a list of caches along a route. Currently the only way to do this is with Pocket Queries and utilities developed by other geocachers. Determining how to generate Pocket Queries to cover a route has been explored in this thread in the geocaching.com forums.

Once you have the required gpx files with any duplicate listings due to overlapping Pocket Queries filtered out you now have to determine the caches along the route. An arc filter function has been developed by GPS Babel which is used by GSAK (Geocaching Swiss Army Knife) "under the hood".

The arc filter as described in GSAK is "... designed to include waypoints based on their proximity to an arc, which is a series of connected line segments similar to a route or track but without any other associated data other than the coordinates" Waypoints in our case are geocaches. Rather than entering the coordinates manually, MicroSoft Streets and Trips (amoung other programs) can be used to generate a file which can then be used by the arc filter in GSAK. Of course GBSBabel is working hard behind the scenes and arc filter functions could be performed by GPSBabel alone if you're so inclined.

This tutorial is divided into three sections:

  1. Setting Up A Route In Streets and Trips
  2. Using the Arc Filter In GSAK
  3. So How Do I Know?
The example used is a route between Edmonton and Calgary Alberta and caches within 10 kilometres of this route are found.

If you have any questions or comments please e-mail me.


Setting Up A Route In Streets and Trips



On the Standard toolbar, click "Route Planner"





Select the beginning of the route with the cursor. In our example Edmonton is selected and appears in the route planner window. Click on the "Add to Route" radio button.





Edmonton has been set as the first point on our route.





Repeat the process to add the second point on our route.





A tip from cacher Windchill gives another method of adding additional points along a route. To use this method first define the start and end points of your route and click on the "Get Directions" radio button to generate a set of driving instructions. Your route will be highlighted in green on the S&T map.

"I figured there must be an easy way to allow S&T to automatically generate the route, then go back and add the intermediate stops at major turns. Using the "enter a name" metiond to add a stop in the middle of an already generated route is kind of a pain. I found that if you click on the route itself, the pointer changes to a little flag. If you then click again, and drag just a little bit it will insert a stop for you."

Additional points are added to complete our route to Calagary. Points should be added at major turns in the route to avoid cutting across corners. Streets & Trips and GSAK will handle almost any number of points without complaint so adding more points at this stage is easy to do and increases the accuracy of the process.

An important point to note here is that while the route generated in Streets and Trips will follow the roads between the points we created the Arc filter in GSAK will assume straight lines between these points. So again, use as many points as required to define your route accurately.

Save this Streets&Trips file somewhere you can find it easily again! In the example below it's saved to the Files directory/folder.






Although not necessary for our project you can click on the "Get Directions" radio button to generate a set of driving instructions before shutting down Streets and Trips. These can be useful if you're travelling on strange roads or planning a longer trip.


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Using the Arc Filter In GSAK




Open GSAK and click the filter icon on the tool bar.





On the Set Filter Arc/Poly tab (1) select Arc/Line for filter type (2) select load from file (3) highlite the Streets&Trips .EST file we just created and (4) select Open.







(1) GSAK imports the coordinates of the route points from the EST file. (2) Now set the distance from the route that you want caches selected. Save this filter if you want to use it again in the future. (3) Select Go to run the filter.





GSAK filters the database to show the caches within 10km of the route. In my example 238 out of a total 758 caches in the Alberta database are shown in the filter.

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So How Do I Know?

... if the process worked correctly? Streets and Trips has a function similar to the arc filter so let's check our results in the .est file that we created earlier.



Export your GSAK complete (not filtered) database to a Streets and Trips CSV file which is a plain text file in which each line represents a waypoint description consisting of a comma-separated list of values. Import this file as described in
Importing waypoints to Microsoft Streets & Trips





Now that you've imported your caches (in my example they're indicated by the geocaching box icon) select "Find Nearby Places" from the Tools menu.





In the Find Nearby Places window (1) select Around Entire Route (2) set Search to match our GSAK filter (in my example 10km) (3) click on Search (4) and the results should show the same number of caches. In my example 238 caches are indicated to fall within 10km of the route. I've also circled in blue a couple of caches that fall outside the 10km wide zone on both sides of the route (highlited in yellow) and are excluded from the list.

If your results don't match it may be a result of having to few route points. Remember that while the route generated in Streets and Trips will follow the roads between the points we created the Arc filter in GSAK will assume straight lines between these points. So again, use as many points as required to define your route accurately.




Many thanks go to the developer of GSAK - Clyde England

Thanks also to all the sites I've linked to.

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Related Information Links

GSAK (Geocaching Swiss Army Knife)

GPS Babel

Drag and Drop for Windows - example

Importing waypoints to Microsoft Streets & Trips

Tips for hand-building routes to use as arc files

Hyper Optimizing Trips with Microsoft Streets & Trips



Geocaching Along a Route
GPX, KML, EST And ARC File Creation Resources


Markwell's Route Planning: Waypoints Along a Route

Geocaching and Route Planning

Golden Horseshoe Geocachers - ARC Builder

Using Google Earth to Generate Routes For Geocaching

Using Streets & Trips to Generate Routes For Geocaching

Using Streets & Trips to Generate Waypoints For an Arc Filter to Find Caches Along a Route in GSAK

Using Streets & Trips to Generate Routepoints For A GPX File For Use With The Caches Along a Route PQ at Geocaching.com

Using Streets & Trips to Generate Polygons For an Arc/Poly Filter in GSAK


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Updated 2006/09/28
Oh Canada Alberta
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