April 18, 2008
Since we’re one day away from the Cache-In Trash-Out Geocaching Event I wanted to write another post about geocaching with your PN-20. While seeking a cache is a lot of fun, my experience with the Bears In The Bushes cache has taught me that hiding a cache can be even more exciting!
Since, arguably, the most valuable clue for a geocache is the cache coordinates, it is important to post a reading that is as accurate as possible. The waypoint averaging feature available on the PN-20 will help you increase your cache coordinate accuracy by calculating a rolling average as you gather GPS readings for a given location.
When you create your geocache waypoint, you will see an Avg (average) button at the bottom right corner of the page.
Press this button to display the Average Page showing GPS information, including the number of readings and the estimated accuracy for the location. Allow the waypoint to average until the change in estimated accuracy slows down. I don’t have a firm number but try to average for at least 100 readings.
The key to getting your best location coordinate is in returning to the same location over several days and at different times of day to update your GPS average. Returning over several days increases the random nature of your readings… Since your GPS device is influenced by the location of the satellites sending signals and by the atmosphere those signals travel through, it’s best to repeat your readings to average the environmental conditions with the readings on any given day.
To continue averaging when you return to your cache location press the Menu button and then choose Average Waypoint…
This will display the Averaging Page and continue to gather GPS readings to include with the values gathered during your previous visit.
Don’t worry if your estimated accuracy goes up when you first start. The device is averaging readings for the same location but with different environmental influences… that’s why we need to average over multiple visits. When you view your waypoints in Topo USA, you’ll be able to see the benefits of averaging over multiple days. The location of your cache will move with each update. If the cache location doesn’t move or moves only a little, you’ve averaged well and are ready to complete your listing!
Here is a link to some very informative GPS accuracy and averaging research by David Wilson, a mathematician from Kent State University.
Let me know if you have any questions about getting the best location information for your geocaches…
-Chip
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Tips & Tricks | Tagged: Geocaching, GPS, PN-20, Technology | 
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Posted by Chip Noble - Design
April 2, 2008
Hidden features are a tough topic in the UI group, where we try to make sure everything is accessible and easy to use. If you have to read the manual to find the feature, there’s a good chance you will never discover it.
Having said that, sometimes requests come along for shortcuts that save time but aren’t necessary to complete a process. We’ve found that the PN-20 — with its limited number of buttons and small screen — was a good candidate for some of these shortcuts. We’ve documented them in the manual and we’re comfortable that they aren’t required to complete any tasks, but they do save time. So here’s my list of shortcuts … with a few general tips sprinkled in.
Menus
- When you are at the top of a menu, press up on the arrow keypad to move all the way to the bottom. All menus and page lists are looped together in this way.
- The IN and OUT buttons move up and down a menu or list one page at a time. Rather than scroll through the entire page, press OUT to quickly jump to the next page.
Keyboard
- To edit text, start typing to replace all the text or use the left and right arrow keys to add to the beginning or end of the text.
- Press OUT to quickly jump to the OK button.
- Press IN to quickly delete the last character entered.
- The edges of the keyboard are linked like the top and bottom of a menu. You can scroll left to get to the right or up to get to the bottom.
- Press the shift key (up arrow) once to make a single letter upper case, press it a second time to use all upper case letters, and press it a third time to return to lower case letters.
Find
- Find By Name performs a Near Map Center search until you add extra search information like City and State.
- The Find menu offers two Find By Name choices: Begins With and Contains. Consider using Contains if you’re not sure of the search name spelling.
Satellite Page
- If you’re working with the PN-20 indoors, press MENU. At the top of the menu, Disable GPS is highlighted. Press ENTER to disable GPS and make the device run faster. This is nice if you’re panning around on a map. To enable it, repeat the process (Enable GPS will display in the menu).
Map Page
- If you’re looking for the fastest map draw for driving, set your Orientation to North Up, choose the Street View Map Style, turn off any imagery, and zoom out to show mag 12 or .25 mile scale.
- Use the Measure Distance option in the Map menu to determine area by connecting the beginning and end of a polygon. You can use this to measure the acreage of a piece of land.
Trip Info Page
- When resetting info, clear the check box next to Reset Device Odometer if you’d like to keep track of how far you’ve gone with your PN-20 during a season. Select the check box to reset the other Trip Info fields if you’d like to see those statistics for that particular trip.
Waypoints
- New waypoints are named based on your previous waypoint label. This makes it easy to mark a series of similar waypoints like “Checkpoint 001,” “Checkpoint 002,” and “Checkpoint 003.”
- Change the symbol for a waypoint to mark it as completed, and then use Delete By Symbol from the Waypoints list menu to delete your completed points. Use this to delete found geocaches from your cache list.
Tracks
- Save your tracks after completing your trips; it will give you clean tracks when you view your data in Topo USA or XMap.
Routes
- Press ENTER while highlighting a point in the Route list to Move or Remove it. Press up or down on the arrow keypad to move the route point, and then press QUIT to save the change.
Sun/Moon, Tide, and Hunt/Fish
- Pan the map to a new location before viewing the Sun/Moon, Tide, or Hunt/Fish pages to see information for that area.
Device Setup
- Be sure to enable and disable Daylight Saving Time based on where you live. This adjusts the time displayed on the PN-20.
- Enter your owner information; it will help someone return the device to you should you lose it.
Screen Shots
- If you would like to take screen shots of your current PN-20 display like I’ve done here, just create a folder on your SD card named “screenshots.” Each time you press the POWER button on the PN-20, a chime will sound letting you know that a screen shot has been taken. Remove the screenshots folder from the SD card when you are finished.
1 Comment | Tips & Tricks | Tagged: GPS, PN-20, Technology, Topo USA, XMap | Permalink
Posted by Chip Noble - Design
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