Abstract: Methods and associated apparatus and programs for computers for operating geolocation devices are provided. The methods include determining the duration of a time interval during which the device is configured to remain active, responsive to a comparison between an estimate of benefit of remaining on for that time interval and an estimate of cost of remaining on for that time interval. The estimates of cost and benefit may be determined in response to user-selected parameters where by the end-user may effect a trade-off between battery life and receiver sensitivity. The methods also include varying the maximum duration of each listening period whereby to conserve battery power.

Abstract: The present invention provides a non-white construction surface comprising a substrate, a first reflective coating on at least a portion of an outer surface of a substrate, such that the substrate with this first reflective coating exhibits a minimum direct solar reflectance value of at least about 25%, and a second reflective coating on at least a portion of the first reflective coating, wherein the combination of the first reflective coating and the second reflective coating provide the substrate with a reflectivity of at least about 20% at substantially all points in the wavelength range between 770 and 2500 nm.