Detection and identification systems for humans or objects

A detection system for detecting targets in a scene, comprising:

• an illuminator configured to generate electromagnetic radiation and thereby illuminate the scene comprising people;
• a detector configured to receive electromagnetic radiation from the scene;
• a plurality of retroreflective tags, each attached to or positioned near a corresponding target, each retroreflective tag having a respective, unique code, each retroreflective tag being configured to receive the electromagnetic radiation generated by the illuminator and reflect the electromagnetic radiation generated by the illuminator toward the detector, each of the plurality of retroreflective tags having retroreflective portions and non-retroreflective portions that, when the electromagnetic radiation generated by the illuminator is incident thereupon, reflect the electromagnetic radiation generated by the illuminator in a pattern that corresponds to the respective, unique code for the retroreflective tag, wherein the respective, unique code for the respective retroreflective tag is unique to the respective retroreflective tag and the corresponding target;
• and
• an image processor in operative communication with the illuminator and/or the detector, the image processor being configured to:
• analyze the electromagnetic radiation received by the detector to determine a presence of one or more of the plurality of retroreflective tags,
• identify one or more unique targets present in the scene based on the respective, unique code of each retroreflective tag of the plurality of retroreflective tags detected by the detector, and
• count a number of unique targets present in the scene based on the one or more unique targets.

A detection system for detecting targets in a scene, comprising:

• an illuminator configured to generate electromagnetic radiation over a first wavelength range and illuminate the scene;
• a detector configured to receive electromagnetic radiation from the scene illuminated by the illuminator;
• a retroreflective tag attached to or positioned near a target;
• and
• an image processor in operative communication with the detector, the image processor being configured to:
• analyze the electromagnetic radiation received by the detector to determine if the electromagnetic radiation received by the detector is indicative of the retroreflective tag being in the scene,
• update a probability of the target being present in the scene to a first value if the image processor determines that the retroreflective tag is present in the scene,
• analyze the electromagnetic radiation received by the detector to determine a value of an attribute,
• compare the value of the attribute of the retroreflective tag to an expected value of the attribute, and
• if the value of the attribute of the retroreflective tag matches the expected value, update the probability of the target being present in the scene to a second value, the second value being greater than the first value.