Light source position detection apparatus, light source tracking apparatus, control method and program

A light source tracking apparatus, comprising:

• a light source sensor that includes a condensing section that condenses light emitted from a light source to be detected, an image pickup device that receives the light condensed by the condensing section, and infrared light image forming means for forming an image of infrared light that passes through clouds on the image pickup device, out of light emitted from the light source to be detected without forming any image of visible light on the image pickup device;
• a control section that detects a position of the light source to be detected based on per-pixel brightness information received by the image pickup device and outputs a drive signal based on the detected position of the light source to be detected;
• and
• a drive section that moves the light source sensor based on the drive signal and tracks the light source to be detected,
• wherein the control section performs:
• a first acquisition process of acquiring per-pixel brightness information from the image pickup device;
• a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device;
• a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed,
• a process of rounding down brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process;
• and
• a process of detecting the position of the light source to be detected based on brightness information after the rounding down process.

A method for detecting a light source position for a light source position detection apparatus, the apparatus comprising:

• a condensing section that condenses light emitted from a light source to be detected;
• an image pickup device that receives the light condensed by the condensing section;
• and
• infrared light image forming means for forming an image of infrared light that passes through clouds on the image pickup device, out of light emitted from the light source to be detected without forming any image of visible light on the image pickup device,
• the method performing:
• a first acquisition process of acquiring per-pixel brightness information from the image pickup device;
• a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device;
• a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed;
• a process of rounding down brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process;
• and
• a process of detecting the position of the light source to be detected based on brightness information after the rounding down process.

A program for controlling a light source position detection apparatus, the apparatus comprising:

• a condensing section that condenses light emitted from a light source to be detected;
• an image pickup device that receives the light condensed by the condensing section;
• infrared light image forming means for forming an image of infrared light that passes through clouds on the image pickup device, out of light emitted from the light source to be detected without forming any image of visible light on the image pickup device;
• and
• a control section,
• the program causing the control section to perform:
• a first acquisition process of acquiring per-pixel brightness information from the image pickup device;
• a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device;
• a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed;
• a process of rounding down brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process;
• and
• a process of detecting the position of the light source to be detected based on brightness information after the rounding down process.