In order to efficiently and accurately measure geographic locations of ground truth features in the field of resource and environment remote sensing using economical and easy operational GPS instrument

the following experiments were carried out using C/A code pseudo

d

istance differential GPS instrument （DGPS）. Firstly

the effect of base station’s geo

c

enter reference coordinate （WGS84） on location accuracy was evaluated. Secondly

a point was differentially located with a known trigonal control point as base station site and a three parameter Molodensky Model as datum transformation model between WGS84 and Beijing 54. On this point

we then established a temporal base station

which was used to measure the aimed ground truth features in the test site. The location accuracy attained by this route was evaluated as well. It was found that DGPS measured map is of highly absolute accuracy （2\

5

m）

and this absolute accuracy does not change with the minor error of geo

r

eference coordinate of the base station. It is a practical method to measure and establish a new temporal base station

which can be used to carry out the real measure work in the test site. The location error of this method is far under one image pixel size （25m） with one geo

r

eferenced TM image as evaluation reference. However

if the trigonal control point and datum transformation model do not exist

the result of base station single point absolute location can be used as reference coordinate

the measured result of which can be geo

r

eferenced to remote sensing image using some tiepoints on the basis of the first result above. Because this method does not need to know the geo

r

eference coordinate and datum transformation model

it’s a ecnomical and practical method for resources and environment remote sensing.