First, it is difficult to carry out precise observations during the night, and secondly, there are practically no capacities to ensure continuous human observations. The development of measuring equipment, mostly of those based on laser technology, then brought opportunities towards automatization of cloud observations. Recently, laser ceilometers are used to estimate the heights of different cloud layers. Ceilometers emit short laser signals towards the sky, and determine the height by measuring the time it takes for a pulse of laser light to be scattered back from a cloud base (or ceiling). The advantage of the ceilometers lies exactly in the high precision of their measurements of cloud height as well as in their ability to work in a continuous regime. However, the largest disadvantage of the ceilometers is the fact that they only report point measurements above the ceilometer location (or, at larger airports, there are a few points available). Consequently, the point character of the ceilometer measurements is the main reason why they are not suitable for a correct estimation of the cloud coverage. Ultimately, cloud type cannot be determined by ceilometers at all. Automated tools also do exist to measure the second meteorological variable discussed herein, i.e., the visibility. There are generally two types of sensors to determine prevailing visibility: transmissiometers and forward scatter sensors. These operate on the basis of different principles. Transmissiometers measure the transmittance, i.e., a beam of light is emitted horizontally to a sensitive receiver several meters away, and the visibility is determined proportionally to the reduction in the signal intensity. In contrast to this, forward scatter sensors make use the principle of scattering by particles that are suspended in the air. In this type of sensor, a beam of light is emitted at an angle from a sensitive transmitter, and the amount of light scattered into the receiver is measured. By choosing the correct angle between the transmitter and the receiver, the extinction coefficient is estimated. Forward scatter sensors are suitable at measuring the transparency of the atmosphere; nevertheless, they only supply a short distance measurement of air between the transmitting and receiving heads (on the order of a few tens of cm, according to the manufacturer). Automated visibility sensors are generally designed to measure the prevailing visibility by assuming that the conditions between the sensor's receiver and transmitter represent the nominal conditions around the horizon. As the actual visibility may not be homogeneous over the entire domain, it is quite possible that the visibility estimate of the laser sensor could differ from that of a human observer [2]. That is why differences between forward scatter sensors, transmissometers, and observers exist. Transmissioneters and forward scatter sensors are associated with a number of further drawbacks: (a) they are scarcely available uniformly, and their spatial distribution is far from ideal, even within a given country, (b) they can only measure visibility at exact, pre-defined measuring points (Figure 2), (c) their price is relatively high, and (d) they are unable to spot minimum visibility and its direction that is required by the International Civil Aviation Organization (ICAO) [1]. A novel approach to a determination of visibility by remote and/or automatic sensors is using camera images. This solution addresses all the above-mentioned problems (a)-(d) as: (a) a lot more cameras than sensors operate on a regular basis, but they are generally not used to estimate visibility; (b) cameras can cover the entire environment in contrast to the visibility sensors; (c) the price of cameras is lower than that of the dedicated, high-quality sensors; and (d) as a result of a full coverage of the whole environment, the minimum visibility and its direction can be determined. Generally, the camera-based approach to the visibility measurement is rare and novel, but not unseen [3; 4; 5].