Example of merging streaklet clusters into coherent streaks with RNN. The left image shows the detected streaklets before merging, and the right image shows the streaks after RNN merging. The images contain two ground-truth streaks whose starting points are marked with green squares and ending points with red squares. The black numbers show the magnitude of the asteroids, and the cyan numbers show the streak lengths in pixels. The magenta X’s mark the starting points of CNN detections, and the blue X’s mark the ending points. The ground-truth streaks shown here are long, so there are many CNN detection streaklets along them. After merging with RNN, there are single coherent streaks whose coordinates match the ground-truth coordinates quite well.