No flickering. No noise. No artifacts. No hard lights that cast shadows. No fog, clouds, trees or buildings. No moving objects whose appearance is similar to the target and no waving objects that cause the continuous modification of the image in the areas of interest, for example, a meadow with tall grass.

The target must have a minimum height of 30 pixels which is at least 1/10 of the image height. The target must have a minimum area of 100 pixels and stay in the interested area for a time of at least 1 second. The target must maintain a sufficient dissimilarity from the background.

The accuracy to be expected is under ideal environmental and installation conditions. Recall: 95%