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We present results of an investigation into the visualization and measurement of retinal blood flow distribution by means of singleexposure laser-speckle fundus photography. The technique relies on the speckle effect produced when laser light is scattered at a diffusing structure and on the fact that the speckle will be averaged out to some extent when the structure concerned is moving and /or decorrelating. We discuss two alternative techniques used to process the specklegrams obtained from the retina. The first technique uses an analog optical spatial filtering procedure to enhance the resulting variations in speckle contrast. Although first results have shown the basic usefulness of this technique, it suffers from fundamental disadvantages. In the second technique we digitize the specklegram and use digital image processing techniques to (1) convert contrast variations in the fundus photography into color variations and (2) obtain the blood flow of the vessels with a reasonably low statistical error. Subject terms: speckle; metrology; retinal blood flow; digital image processing; flow visualization; flow velocity.Optical Engineering 25 (6). 731 -735 (June 1986).

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Various forms of advanced automation in air traffic control are being developed to reduce air traffic controller (ATCO) workload, support performance, and increase safety. However, higher levels of automation can negatively affect the ATCO's performance, reduce situation awareness (SA), and the usage of automation also depends on user acceptance. Previous studies have shown that automation can be met with resistance from ATCOs, which might lead to disuse. Thus, this paper continues the exploration of ATCOs' expectations of automation to deeper understand ATCOs’ fears and anticipations. Through a questionnaire, operational ATCOs answered questions regarding their current experiences and future expectations regarding automation extend, safety, SA, and workload. The quantitative analysis shows that automation and workload are expected to increase in the future compared with today and that safety and SA are expected to decrease. Even though the participants highlighted that they do not want to become the backup system to the automation, it is in that direction the development is heading. These are worrying results and something the air traffic management community should see as a wake-up call. A well-calibrated attitude towards automation seems crucial to ensure the best human-automation interplay.