| 摘要 |
An improved microwave radiometric system features the employment of incoherent noise illumination of a selected target for improving the measured radiometric temperature contrast between the target and its spatial background and for increasing the distance at which such a target may be detected. Broad band noise illumination (28) is cyclically transmitted and the receiver is cyclically activated in the high frequency signal comparison system under control of a phase locking loop (24, 32, 33, 34, 37) so that optimum comparison is achieved over a variety of target distances. |
