Abstract: Environment measurement methods, systems, media, signals and data structures are disclosed. A first method involves receiving first signals produced in response to a laser beam scattered by the environment, receiving second signals produced in response to a radar beam scattered by the environment, and storing data representing the first and second signals, for use in producing a representation of the environment. A second method involves continuously producing data in response to scattered portions of a laser pulse scattered by respective portions of the environment, during a measurement interval of sufficient duration to receive all the scattered portions, and storing the data, for use in producing a representation of the environment.

Abstract: A system for gathering topographic data for use in computer generation of topographic maps of various forms. This system includes equipment mounted in an aircraft which can be flown over a terrain area which is to be surveyed. The equipment comprises a low frequency radar which is capable of penetrating foliage in the survey area for generating a signal representative of the distance from the aircraft to the terrain surface, a precision altimeter that produces a signal representative of the altitude of the aircraft with respect to a reference plane such as sea level, temperature and humidity sensors for producing signals representative of those quantities, a clock for producing a signal representative of a standard time, and a digital recorder for recording the previously named signals which are produced during over flight of a survey area.