An improved sensor (102) for physiology monitoring in mobile devices, wearables, security, illumination, photography, and other devices and systems uses broadband light (114) transmitted to a target (125) such as the ear, face, or wrist of a living subject. Some of the scattered light returning from the target to detector (141) is passed through narrowband spectral filter set (155) to produce multiple detector regions, each sensitive to a different wavelength range. Data from the detected light is spectrally analyzed to computationally partition the analyzed data into more than one compartment of different temporal or physiological characteristics (such as arterial bloodstream, venous bloodstream, skin surface, and tissue), and into more than one component compound (such as oxygenated hemoglobin, water, and fat), allowing a measure of physiology of the subject to localized to one compartment, thereby reducing the effects of body motion, body position, and sensor movement that can be localized to other physiological compartments or components. In one example, variations in components of the bloodstream over time such as oxyhemoglobin and water are determined based on the detected light, and localized to remove skin surface scattering and reflection, and to minimize changes in the venous bloodstream caused by impact and motion, resulting in an arterial bloodstream signal with an improved signal to noise for the cardiac arterial pulse. The same sensor can provide identifying features of type or status of a tissue target, such as heart rate or variability, respiratory rate, calories ingested or expended, hydration status, or even confirmation that the tissue is alive. Monitoring devices and systems incorporating the improved sensor, and methods for analysis, are also disclosed.