Sunlight intensity or cloud detection with variable distance sensing
View Patent ↗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.
1. A method comprising:
using two detectors, each detector having at least one sensor and a field of view of one of two regions of the sky, to measure sensor data of intensity of solar radiation received from the two regions of the sky;
determining cloud cover at each of the two regions of the sky based on the sensor data measured by the at least one sensor of each of the two detectors and by predicted values from a solar calculator; and
classifying the cloud cover at each of the two regions based on at least the sensor data.
2. The method of claim 1 , wherein the sensor data of intensity of solar radiation received from the two regions of the sky is measured using the at least one sensor of a far detector directed such that its field of view is of a second region of the two regions and using the at least one sensor of a near detector directed such that its field of view is of a first region of the two regions.
3. The method of claim 2 , wherein the second region is farther from a building than the first region.
4. The method of claim 2 , further comprising using the cloud cover classifications to determine a weather condition.
5. The method of claim 1 , further comprising determining a speed of the cloud cover based on the sensor data and using the speed to classify the cloud cover.
6. The method of claim 1 , further comprising directing the one or more detectors to the two regions of the sky by rotating at least one of the detectors.
7. The method of claim 1 , further comprising controlling one or more electrochromic windows at a building based on the cloud cover classification.
8. The method of claim 1 , wherein the at least one sensor includes one or both of an infrared sensor and a photosensor.
9. The method of claim 1 , wherein the measured sensor data includes intensity measurements of infrared radiation in a wavelength range between 8 μm and 14 μm.
10. The method of claim 1 , wherein the cloud cover is classified based on the sensor data and further based on weather condition data received through a network.
11. The method of claim 1 , wherein the cloud cover is classified by cloud consistency and/or weather modifier classifications.
12. The method of claim 1 , wherein the classifications of the cloud cover are used as input to control one or more building systems.
13. The method of claim 1 , wherein the classifications of the cloud cover are used as input to determine instructions for controlling one or more electrochromic windows.
14. The method of claim 1 , further comprising using the cloud cover classifications to determine a current or impending weather condition at a building.