planewood

Thanks, but I could fine nothing remotely similiar to my two questions.

Will it do 'averaging' at a site to improve accuracy? Can someone explain? I want the best readings I can get at my surveyed stakes. Can it be calibrated at a bench mark or triangulation station? In other words, stand at the site with the site coordinates entered in hopes of improving accuracy in the vicinity. I obviously don't know what these functions are supposed to be called, or if they even exist.

I understand one can enter either type of coordinate into a GPS. But when entering lat/lon is it necessary to also set the datum to WGS84? Also, isn't NAD83 just an old name for WGS84? I guess that since all my work with be in UTM zone 15R and using WGS84/NAD83 that I should just set those in and forget it??

Thanks! Just what I was looking for!

Thanks NEO - For benchmark text files I mean like this: http://www.ngs.noaa.gov/GEOID/GPSonBM99/format99.txt and like this: http://www.ngs.noaa.gov/GEOID/GPSonBM96/nad5379.txt The site you sent me to had lots of pics, but nothing organized in the form of tables.

Never owned a GPS before and this is only my 2nd day on this forum! But, I'm considering purchase of the Garmin 60cx. I'm not a 'geocacher', at least not yet. I do have lots of mapping experience and experience with coordinate systems and am computer literate. (was a systems analyst for 35 years in the oil business) My primary reason for wanting a handheld GPS unit is for geographical mapping (not street mapping) in heavily wooded areas. Here's some of my questions (pertaining to Garmin): 1) can I upload my own topo sheets and aerial photos to it? Has anyone 'broken' or 'reverse engineered' the Garmin format yet? If so, who and how do I get there? I got tons of old topo sheets and aerial photos laying around and have access to a wide body scanner. 2) are there any text files on the internet for all surveyed Bench Marks, at least for Oklahoma. I think there is at least one bench mark (brass plate) per section (square mile). 3) can I write files to the microsd card that comes with the 60cx using a sd card adapter and the sd reader on this computer? Or, can I only do it by attaching the gps through their supplied USB cable and then by using a program like EasyGPS?? 4) Would getting an antenna help in wooded areas? That's all I can think of for now.

I was just told today by an Ebay seller of Garmin devices that he is not recognized by Garmin as an 'Official Retailer' and as such would not warranty the gps's he is selling on Ebay.