由于闭口式风洞不能有效模拟在大气飞行的引信电机周围的流场，自行设计并建造了超音速射流吹风装置。采用激光双曝光全息干涉技术深入研究超音速射流吹风装置的流场结构并配合引信发电机外部流场的密度定量测量。在拍摄到了比较清晰的密度干涉条纹照片后，还要从图像的条纹中辨识出密度场等值线，才能利用干涉原理计算出当地条纹的密度。对图片条纹进行了辨识处理，并考虑到由于图像曝光程度的不同导致的图像左右部分亮度区别，设计了多重阈值的图像二值化处理算法。经检验，该图像的二值化处理结果与肉眼直接观察得到的条纹有良好的一致性和保真性。在随后处理过程中采用了一种按行的曲线像素搜索算法来细化二值化的干涉条纹，为以后从密度干涉条纹中提取射流密度场的程序化后处理工作打下了基础。若要完全实现密度场的自动提取，还有大量的后续工作有待开展。

A supersonic jet facility was built to account for the problem that wind tunnel test of fuse electrical machinery is not capable of simulating the flight-test flow conditions. To have a thorough insight into the flow fields of this supersonic jet facility as well as to measure the flow fields around certain fuse electrical machinery, laser dual hologram interferometry was employed in present study. The obtained density strakes, which were of different brightness in the photo, should first be identified before it can be used in automatic extraction of density fields. A multi-leveI threshold algorithm~was proposed to account for the brightness difference of the photo in converting them into white-black strakes. The results show that, this method gives both consistent results in sense of human perception and satisfactory results to find uniform regions in the image plane. Then line thinning is conducted for preparations of automatic identification of density fields based on the white-black strakes. These works are base of automatic extraction of density field, and future works should also be conducted to finish the whole automatic extraction process.