Hi Lauren, What you are trying to do is actually quite easy to accomplish as long as you have access to ArcMap. You can use the "generate regular points" tool included in Hawth's Analysis tools ( http://www.spatialecology.com/htools/regpnts.php). Once you have generated the points, you can load them onto your Garmin using another program called DNRgarmin ( http://www.dnr.state.mn.us/mis/gis/tools/arcview/extensions/DNRGarmin/DNRGarmin.html). Both of these programs are relatively simple to use and shouldn't be too difficult to figure out. If you still need step by step instructions let me know and I can try to help.
The only problem I see with your plan is that the Garmin eTrex Vista is not as precise as you may need. The precision on Garmin units I have used is often up around 12m which would make it difficult to sample a grid spaced at only 20m. On a clear day with good satellite reception your precision may be acceptable but I am not sure if I would design my sampling plan to rely on the GPS unit. I would at least use flagging to ensure you sample the same locations each time you sample. Hope this helps. Good Luck! Dave Miceli On Fri, Jun 18, 2010 at 10:49 AM, L Quinn <[email protected]> wrote: > Dear list, > > I need to sample plants in a regularly-spaced grid pattern. I'd like to use > my Garmin eTrex Vista GPS unit to help me stay in the grid pattern while I'm > walking around in the grassland, but I don't know how to do this. One > problem is that I won't know exactly where I'll be sampling ahead of time, > so I can't load in detailed maps with overlaid grids (and I don't know how > to do that, either!). > > Is there an easy way to get the Garmin to generate a fine-grained grid > (e.g. 20 m between points) wherever I happen to be standing in the world > (I'll be in Japan)? Or am I stuck with reeling out measuring tapes? This is > difficult in the system I'm sampling, as the plants are generally very tall > and hard to navigate through. > > Any and all suggestions are appreciated, especially if they are written as > instructions to a 5-year-old. All I've used my GPS unit for in the past is > marking waypoints and recording tracks. > > Thank you!! > > Lauren Quinn > > _________________________________________________________________ > The New Busy is not the too busy. Combine all your e-mail accounts with > Hotmail. > > http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4 >
