I have researched, & so far found that GPS device needs the view of satellite, open sky to work properly. But, I'm confused because one of the MNCs claim to have built a system having GPS that works under the underground steel pipelines.
It might be possible through some other hardware solutions which are used in GPS-denied environment. Researchers have used underground GSM, INS, etc. to accurately localize objects in a non-satellite environment. Another thing to note is that GPS (Global Positioning Service) primarily uses Satellites for geolocation but a differential GPS (ground based) is also used for quick location information. Similar concept can be used in underground navigation/geolocation research through use of nodes installed underground (which are connected using wires to GPS devices above the ground) inside the pipelines. I suggest looking for non-GPS navigation methods developed or proposed recently.
Jazak Allah. I would like to share that we have a wire welded to the under ground steel pipes that comes out of the soil to be used to measure pipe-to-soil potential. These wires/ leads are located at every 3 kms. Could they work as antenna for differential GPS(ground based)?
Adding any kind of signals to these wires might disrupt your pipe-to-soil potential readings but you need to run some test to make sure what is the exact case as it depends on what method is being used to get those readings. If the effect is nil, then they can be used. Two other equipment, one DGPS and another beacon sort of wireless transmitter (or tracker) would be required on the pipe end of the wire. But another problem which might arise is the distance between these wires. 3 km is quite a long distance to track any object inside a pipe. Probably those detectors can give intermittent geolocation information whenever the object passes by the tracker and then a local INS (or a optical sensor or low power LiDAR, etc.) may be used to keep track of its movement inside the pipe. Additional accuracy may be increased by detecting the speed of object and the geological map of pipe distribution. What do u think?
Mohd, being 2 meters under the surface will give you sufficient soil attenuation that your GPS receiver will not be able to track the satellites and therefore not be able to provide you with a position. If there is a steel pipe overhead in addition to the soil, the situation becomes even worse. So the answer to your question is, unfortunately, no.
It has been suggested to have a wire run to the surface and if you can do this, fine. But you will measure the position of the antenna on the surface, not the position of the buried GPS receiver.
Bertram: I agree with you. What I was suggesting in essence is measuring the position of the antenna on the surface + measuring the position of the object in the pipe relative to this antenna, giving us its actual location. Further, using the map of the pipe, etc., some sort of data fusion might be useful in getting more accurate positioning information, right? What do u think>