Abstract:

Since 2002, the single point absolute positioning and track hand GPS have been used in field quality con2 rol by Q IGMR during the 1∶50000 stream sediment survey. The channels pointing mistakes caused by using topographic map and other p roblems such as pointing distortion and samp ling random caused by human factors can be avoided. It not only raises the accuracy of field pointing, but also enables the managers to know p rogress in the field and ccuracy of samp ling through Arcview GIS software. The things must be done during positioning as follows: choose roper correction control points; correct the parameters rightly; conformable hand GPS; turn track on.

Key words: Hand2GPS, Stream sediment, Single point absolute positioning, Survey, Quality control