DOPPLER VIBROMETER, DOPPLER VIBROMETER MEASUREMENT METHOD, AND MEASUREMENT PROGRAM

To provide a Doppler vibrometer to be used in a distance being at the same degree as that of or longer than a coherent length of continuous light to be radiated by a continuous light source.SOLUTION: A Doppler vibrometer comprises: a measurement light generation part 50 including a continuous light source 1 for generating continuous light, an optical splitter 2 for branching the continuous light into two lights and respectively outputting the lights, an optical modulator 8 for frequency-modulating one of the output lights of the optical splitter 2, and light variable delay means 20 for giving a delay time to the light frequency-modulated by the optical modulator 8 and outputting the light as local oscillation light ELO; an antenna part 40 for irradiating a target 200 with signal light ES using the other one of the output lights of the optical splitter 2, so as to receive diffuse reflection light ED generated in the target 200; and a processing part 60 for causing the diffuse reflection light ED received by the antenna part 40 to interfere with the local oscillation light ELO, so as to perform coherent detection. The light variable delay means 20 gives the delay time of a delay amount corresponding to a propagation time of the signal light ES based on a distance from the target 200 measured by a range finder 7.SELECTED DRAWING: Figure 1 【課題】連続光光源が照射する連続光のコヒーレント長と同程度又はこれより長い距離で使用する。【解決手段】連続光を生成する連続光光源１、連続光を２分岐してそれぞれ出力する光スプリッタ２、光スプリッタ２の一方の出力光を周波数変調する光変調器８、及び光変調器８で周波数変調された光に遅延時間を付与して局部発振光ＥＬＯとして出力する光可変遅延手段２０で構成される計測光生成部５０と、光スプリッタ２の他方の出力光を用いたシグナル光ＥＳをターゲット２００に照射し、該ターゲット２００で生じる拡散反射光ＥＤを受光するアンテナ部４０と、アンテナ部４０で受光した拡散反射光ＥＤと局部発振光ＥＬＯとを干渉させてコヒーレント検波する処理部６０とで構成され、光可変遅延手段２０は、距離計７で計測したターゲット２００との距離からシグナル光ＥＳの伝播時間に相当する遅延量を局部発振光ＥＬＯに付与する。【選択図】図１