Manitoba Geocaching Association

[bevro]

I have been caching for a little over a year to date and thought I had things more or less under control when it came to being able to locate coordinates, no matter whether urban or rural.  I recently came back from a business trip in Dallas and had difficulty in the downtown area where you are stuck in concrete canyons with only 5 or 6 satelites available.  I found a number of caches in park like settings but struck out completely on two micros and was close enough (around the corner) on a virtual that the owner allowed me to log.  I had my Lowrance iFinder with me and on the caches I did find, accuracy was within the normal 3-7 meters.  On the 3 I had problems with, I was lucky to see an error of anything smaller than 85 m and generally upwards of 135m!  Kind of difficult when you're looking for a micro.  Anyone have any suggestions how to combat these peculiar sites?

[burchil]

I had this problem in San Fransisco earlier this year.  Urban canyons are a problem with multi-path errors and just blockage.  I do what I usually do when working in dense bush anywhere else.  Find several open places (some times this is quite a distance) or even not so open but enough sky view to get sat coverage - sometimes this means standing in the middle of an intersection .  Then triangulate the final location.  I also read all of the logs and zoom in as much as possible on one of the maps (e.g. google maps) to get a feel for the location. Sometimes just waiting for satellites to come into view over an urban canyon. I spend lots of time looking at the sat coverage page until I find something that looks good (and I believe). It does take longer but I was somewhat successful.  

I suspect that the posted location of some of these urban caches have problems as well.

[TurdleEggs]

Burchil’s triangulation method often works for me. I finish it off by walking a straight line tangent to the cache and coming in 90 degrees and pacing it off (my paces are exactly 1 metre). Also Google Earth helps sometimes and waiting for the constellation to come into alignment if you’ve got the time.



The crazies in Victoria use external backpack antennas to get more signal in the high canopy out there. But they’re also packing 2 or 3 GPSr’s (sometimes a Trimble) and using laser distance finders.

[ertyu]

Just keep walking around and manually triangulating the results. Get good bearings from open areas as suggested. Start looking for hiding locations instead of following the arrow.