( ( ( This frequency ) ( when ( ( multiplied ( by ( ( the distance ) ( between ( ( the beams ) ( at ( that altitude ) ) ) ) ) ) ) ( ( gives ( the wind ) ) ( velocity ( in ( ( the direction ) ( along ( ( the plane ) ( of ( the five ) ) ) ) ) ) ) ) ) ) ) ( beams . ) )
(ROOT (S (NP (NP (DT This) (NN frequency)) (SBAR (WHADVP (WRB when)) (S (S (VP (VBN multiplied) (PP (IN by) (NP (NP (DT the) (NN distance)) (PP (IN between) (NP (NP (DT the) (NN beams)) (PP (IN at) (NP (DT that) (NN altitude))))))))) (VP (VBZ gives) (NP (DT the) (NN wind)) (NP (NP (NN velocity)) (PP (IN in) (NP (NP (DT the) (NN direction)) (PP (IN along) (NP (NP (DT the) (NN plane)) (PP (IN of) (NP (DT the) (CD five)))))))))))) (VP (VBZ beams)) (. .)))
This frequency when multiplied by the distance between the beams at that altitude gives the wind velocity in the direction along the plane of the five beams.
(ROOT (S (NP (NP (NNP Distance)) (PP (IN over) (NP (NP (NN time)) (PP (IN in) (NP (DT a) (VBN given) (NN direction)))))) (VP (VBZ determines) (NP (NN velocity))) (. .)))