Walking noise is a type of noise that can occur in astrophotography when capturing long-exposure images, particularly with unguided mounts. It is caused by slight movements or vibrations of the camera or telescope that occur during the exposure, leading to a slight shift in the position of the stars in the image. These shifts can cause the stars to appear elongated or misshapen, and can reduce the overall sharpness and quality of the image.

Dithering is a technique used to reduce walking noise and other types of noise in astrophotography. By intentionally shifting the position of the camera slightly between each exposure, dithering helps to randomize the walking noise and other sources of noise, making it easier to separate the signal (the stars and other astronomical objects) from the noise. This can result in a cleaner, sharper image with better detail and contrast. Drizzling is another technique that can be used to enhance the resolution and detail of astrophotography images, particularly when dealing with small or faint objects.