1. A scanning microwave detection apparatus for providing a moisture profile along the width of a predetermined sample, comprising: a plurality of spaced moisture sensors, each of the sensors adapted to couple microwave energy with a finite area of the sample; each sensor having a first filter coupled to its input and a second filter coupled to its output, the first and second filters forming a pair, the pair of filters coupled to each sensor being tuned to the same frequency and each of the pairs of filters being tuned to a different predetermined frequency within a selected frequency band thereby having a substantially non-overlapping frequency band-pass; microwave source controlled to sweep through the frequencies within the selected frequency band, said source being coupled to the input filters; and detector means coupled to the output filters for sequentially detecting energy outputs of the sensors which are a function of the moisture content of the sample.