f PROGRESS ON GEOPHYSICAL TECHNOLOGIES IN BUSY TOWN OF CITY

There are two problems on shallow exploration in city: (a) Frequent exposure to vibration noise and terrestrial electricity peculiar to city. Seismic methods are usually highly embarrassed by the vibration from the cars, pedestrians, engineering construction and operating metro lines; (b) Many geophysical exploration methods cannot meet the requirements on desired exploration depth and resolution. The Landsonar (seismic reflection method) and Differential electric sounding method were new technique used in recent years .Good results from shallow engineering surveys have been obtained .Landsonar used high and super wide-band frequency , not only advancing greatly the resolution but also avoiding the interference of the vibratory noise of passerby , cars and other machines . The DES machine can avoid the interference of stray electricity and have high resolution. Those two methods can adapt for surveying in city, even in busy and noise city. Their advantages was proved in the practice projects and get the good effect in shallow high resolution surveying in city.