( GPS ( ( is ( ( a ( satellite-based ( , ( radio-navigation system ) ) ) ) ( consisting ( of ( ( ( 24 satellites ) and ) ( ( a ( ground-based infrastructure ) ) ( that ( ( ( monitors and ) controls ) ( the satellites ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP GPS)) (VP (VBZ is) (NP (NP (DT a) (JJ satellite-based) (, ,) (JJ radio-navigation) (NN system)) (VP (VBG consisting) (PP (IN of) (NP (NP (CD 24) (NNS satellites)) (CC and) (NP (NP (DT a) (JJ ground-based) (NN infrastructure)) (SBAR (WHNP (WDT that)) (S (VP (VBZ monitors) (CC and) (VBZ controls) (NP (DT the) (NNS satellites))))))))))) (. .)))
GPS is a satellite-based, radio-navigation system consisting of 24 satellites and a ground-based infrastructure that monitors and controls the satellites.
(ROOT (S (S (NP (PRP We)) (VP (VBP call) (NP (NP (DT the) (JJ worldwide) (JJ radio-navigation) (NN system)) (VP (VBN formed) (PP (IN from) (NP (NP (DT a) (NN constellation)) (PP (IN of) (NP (CD 24) (NNS satellites))))))))) (CC and) (S (NP (PRP$ their) (NN ground) (NNS stations)) (VP (VBP gps))) (. .)))