To evaluate the effectiveness of array detectors for target speckle correction in applications of active heterodyne detection, a high-speed camera heterodyne system was developed. The heterodyne images received by a high-speed camera at a rate of 100 kfps were equidistantly divided into a set of array signals. The phase adjustment of each array element was determined by the adaptive particle swarm optimization algorithm. In this Letter, an array grouping method is also proposed to overcome the difficulty of insufficient computing power due to an excessive number of array elements. The enhancement using the new technique is almost a factor of 2 for the case of a 20×20 detector array. The experimental results demonstrate that, in the presence of target speckle, the array detector can significantly enhance the heterodyne system performance.