Abstract: A method of using reflected satellite signals, such as GPS signals or high orbit satellite signals, to determine information including the steps of: receiving direct and reflected satellite signals from the same satellite at one or more receivers, comparing a power of said reflected satellite signal with a power of the direct satellite signal from the same satellite to obtain a ratio, comparing the ratio to at least one calibrated ratio obtained from calibration data; and determining information from a result of said step of comparing said ratios. The method is useful for the purpose of determining information about the presence or absence of an object, person or animal, the volume of motor vehicle or foot traffic, the aridity of land, monitoring an area for intruders, monitoring parking lots and enhancing security systems.