the NEW methods for detecting under ground things

Hi guys,

Is there any expert to tell me what is the best and recent device for detecting underground things?
In past the guys used to use a metal detectors which was just a very sensitive coil and so on, there were at least 2 problems with such a device.
1: it worked just for metallic stuff
2: you just could hear the beeps to detect that there is something but you could not see it before make a hole.
I would like to know if there is any new device to detect the underground things or yet the people have to use the ordinary metal detectors?

Thanks,

P.S what about the new methods to detect the land mines? Any practical new device/

Ground penetrating radar, and sonic detection are two.

https://www.npr.org/2011/12/28/144393902/young-innovators-detecting-land-mines
appears to be a promising one.

Google on your own, there's tons of information out there.

Thanks so is there ANY portable device to do so? For instance what is the best newest detector for underground detection? Is there any high tech portable device other than the old metal detectors? Is there any portable device capable of monitoring the underground things by vision?

Not practically available, no. There are perhaps commercial/industrial/military technologies, but there is no simple plug and play device you can buy for this type of use.