Seems OK as a start. Agree that the elevations are often less accurate than the plan positions... Just to clarify, are the values listed to be 2x sd (mean to 95% limit) Or 4x sd (lower 95% limit to upper 95%)? Bruce
-----Original Message----- > What about 'position'? I don't think the BCRA grades have much to say about > these. (I'm sure we can make something sensible up) First proposal could be: GRADE; POSITION / HEIGHT error (95% confidence); comment 0 -- position unknown 1 1000 m -- rough estimate / memory 2 100 m -- GPS in bad conditions (canyons, foliage, SA), small-scale map 3 15 / 45 m -- GPS, large-scale map 4 5 / 15 m -- GPS longer observation, distinct features on a large-scale map 5 1 / 3 m -- GIS GPS 6 15 cm -- geodetic GPS, theodolite/total station, technical nivelation 7 5 cm -- geodetic GPS, precise theodolite/total station, precise nivelation Martin
