Thanks to GPS we can work out our post anywhere on the control surface of the Earth , but this technology does n’t work well in certain environment . Inside buildings , underground , underwater , and outside among skyscraper , the signal can get lose , so researchers are looking at alternatives .
One emerging engineering uses very low relative frequency ( VLF ) magnetic signals and quantum sensors , atoms of rubidium that are capable of discover these specific magnetic fields . As reported inReview of Scientific Instruments , VLF magnetic flying field could be used as GPS option in submarines , mines , and more .
" The big issues with very low - frequency communications , including magnetic radio , is poor receiver sensitiveness and extremely limited bandwidth of existing transmitters and receivers , " NIST project drawing card Dave Howe said in astatement . " This mean the data charge per unit is zilch . "
" Atoms provide very firm response plus very high sensitivity . Classical communication need a tradeoff between bandwidth and sensitivity . We can now get both with quantum sensors .
" The increased sensitivity leads in principle to long communication theory range . The quantum advance also offers the possible action to get high bandwidth communications like a cell phone has . "
The sensors mould like a magnetometer . As the magnetic fields hit the rubidium , the twirl rate of the atoms changes and this create a current that can be measured . The sensing element is subject of detecting magnetic signals a million times pocket-sized than Earth ’s magnetic field .
The advantage of this approach vary . The quantum sensors work at room temperature , they are minuscule , they consume very minuscule power , and they should be relatively tawdry to make . They also do n’t require calibration as the system uses a naturally occur place of the molecule . These facts make them a really strong contender to go beyond the limitation of GPS .
But despite the advantages , there are still challenge ahead . There are many magnetised battleground around , so the sign can sometimes become lost in the noise . presently , the scheme has an indoor range of 10 of meters , which is good than what ’s currently potential , but not really a world-wide and versatile technology just yet . It also struggles with accurate positioning . The doubtfulness is about 16 meters ( 52 feet ) , which is still importantly off the 3 - time ( 10 - foot ) mark that the researchers hope to attain .
The scientists are working on ways to increase the signal - to - disturbance proportion by meliorate how the magnetised field is produced , among other thing .
