We described how to create a shapefile from a table of GPS coordinates imported as a dbf file (Method 2).  This table was displayed as a point shapefile on a basemap of county roads.   Handheld GPS locations are not precise.  They give positions within about 100 meters of points on opposite corners of the field.  This is however sufficient to identify the individual fields.  Now, we create a new point shapefile, with points assigned approximately to the center of the fields identified by the plot of the GPS locations. 

Using Method 1, create a new theme called fldscntr by choosing "new theme" from the view dropdown menu.

Note that the positioning of the field centers (represented by a green X on the map below) is done relative to the roads on the base map using the GPS reading only as a general guideline to define the field.  We also use field notes to specify which side of a road  or which corner of an intersection the GPS readings are taken.

This procedure insures that the field centers are properly positioned relative to the base maps.

After positioning the points and labeling them (see method 1), we save the shapefile and stop editing.

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