One of first and second beams (28) of corresponding first and second light (13) are projected into an atmosphere (20) and at least one physical property of the atmosphere (20) is detected from the interference pattern (47) generated from the resulting scattered light (30). The first and second beams (20) are selected responsive to either a detected signal-to-noise ratio (SNR) or a detected aerosol-to-molecular ratio (AMR). The wavelength (740) of the first light (13) provides for either molecular or aerosol scattering, whereas the wavelength (738) of the second light (13) provides for primarily only aerosol scattering. In accordance with a second aspect, scattered light (30) from one or more beams (28) of substantially monochromatic light (13) projected into the atmosphere (20) and received from a plurality of interaction regions (17) or measurement volumes (52) provides for determining wind power (P*) within a region of the atmosphere (20).