Certain aspects pertain to a cloud detector comprising a first detector module directed to a first region of the sky and a second detector module directed to a second region of the sky. Each detector module has a tube enclosing one or more sensing elements. The one or more sensing elements of the first detector module are configured to take weather condition readings from the first region of the sky. The one or more sensing elements of the second detector module are configured to take weather condition readings from the second region of the sky. In one aspect, the cloud detector is configured to detect cloud cover based on these weather condition readings. In some cases, the one or more sensing elements comprise an infrared radiation detector (e.g., thermopile) for measuring infrared radiation intensity and a photosensor element for measuring sunlight intensity.

A photoelectric detection circuit and a photoelectric detector are provided. The photoelectric detection circuit includes a first photoelectric sensing element and a second photoelectric sensing element, and an electrical characteristic of the first photoelectric sensing element is substantially identical to an electrical characteristic of the second photoelectric sensing element; the first photoelectric sensing element outputs a first sensed electrical signal, and the second photoelectric sensing element outputs a second sensed electrical signal; a polarity of the first sensed electrical signal is opposite to a polarity of the second sensed electrical signal, and an amplitude value of the first sensed electrical signal is substantially identical to an amplitude value of the second sensed electrical signal.

Various embodiments are directed to an image sensor that includes a first sensor portion and a second sensor portion. The second sensor portion may be positioned relative to the first sensor portion such that the second sensor portion may initially detect light entering the image sensor, and some of that light passes through the second sensor portion and may be detected by the first sensor portion. In some embodiments, one more optical filters may be disposed within the image sensor. The one or more optical filters may include at least one of a dual bandpass filter disposed above the second photodetector or a narrow bandpass filter disposed between the first photodetector and the second photodetector.

Various embodiments are directed to an image sensor that includes a first sensor portion and a second sensor portion. The second sensor portion may be positioned relative to the first sensor portion such that the second sensor portion may initially detect light entering the image sensor, and some of that light passes through the second sensor portion and may be detected by the first sensor portion. In some embodiments, one more optical filters may be disposed within the image sensor. The one or more optical filters may include at least one of a dual bandpass filter disposed above the second photodetector or a narrow bandpass filter disposed between the first photodetector and the second photodetector.

A daylight sensor for automated window-shading applications that incorporates at least one (and optionally more than one) of three aspects: an optimized Field-of-View (FOV), angle-diversity sensing (via at least two sub-sensors with different FOVs, whose outputs are processed in a particular way to yield the overall sensor output), and multi-spectral sensing (via at least two sub-sensors with differing spectral responses and, optionally, different FOVs, whose outputs are processed in a particular way to yield the sensor output). These aspects improve the correlation between the sensor output and the subjectively-perceived daylight level (especially under glare-inducing conditions, such as in the presence of low-angle direct sunlight), thereby enabling more effective automatic control of daylight admitted into a room.

To calculate a regular-discharge probability of an optical sensor, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability in a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off, and in a second state in which the additional light source's turning-on/turning-off state is different from the first state with a pulse width of the drive pulse voltage the same as the first state, a sensitivity parameter storing portion that stores sensitivity parameters of the optical sensor, and another discharge probability calculating portion that calculates a discharge probability of the optical sensor's regular discharge.

To calculate a regular-discharge probability of an optical sensor, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability in a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off, and in a second state in which the additional light source's turning-on/turning-off state is different from the first state with a pulse width of the drive pulse voltage the same as the first state, a sensitivity parameter storing portion that stores sensitivity parameters of the optical sensor, and another discharge probability calculating portion that calculates a discharge probability of the optical sensor's regular discharge.

A solar spectrum sensor, a consumer device and a method for determining an ambient solar spectrum. The solar spectrum sensor comprises a sensor unit configured for generating respective photo current outputs responsive to different parts of the solar spectrum; a measurement unit configured for measuring the respective photo current outputs from the sensor unit; and a processing unit for determining an average photon energy, APE, value of the solar spectrum from the measured photo current outputs and for determining the solar spectrum based on the determined APE.

An apparatus containing an optical emitter configured to emit optical radiation is provided. Further, the apparatus includes a first hermetically sealed measurement cell filled with a first gas. The first gas is configured to absorb the optical radiation at least partially at one or more predetermined wavelengths. Additionally, the apparatus includes a first microphone arranged in the measurement cell and configured to generate a first microphone signal on a basis of a photoacoustic excitation of the first gas by the optical radiation. The apparatus moreover includes an evaluation circuit configured to take the first microphone signal as a basis for generating a first measurement signal indicating an emission intensity of the optical emitter at the one or more predetermined wavelengths.

Methods of accurately estimating erythemaly-weighted UV exposure, such as the UV Index, and sensors adapted for the same.