초록 ▼

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 penetra

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. The recorder has a recording medium which can be removed from the aircraft and employed at a remote time and place as computer input for effecting generation of topographic maps showing various characteristics of the survey area. Concurrent with the gathering of data in the aircraft, data representative of temperature and humidity at the surface of the survey area are gathered and recorded on a second recording medium. The two recording media can be combined at a remote time and place as computer input to produce highly accurate topographic maps. The system can include a second radar operating at a different frequency from that at which the first mentioned radar operates. One of the radars can accurately penetrate the foliage and the other can measure the distance from the aircraft to the foliage surface so that information concerning the foliage can be generated. The system also includes circuitry for responding to surface water in the survey area so that accurate mapping of rivers, lakes, streams and swamps can be achieved.

대표청구항 ▼

A method for acquiring data for use in producing a computer generated topographic map of foliage covered terrain comprising the steps of overflying the terrain along a flight path, directing at the terrain while traversing the flight path a first radar pulse at a first frequency and a second radar p

A method for acquiring data for use in producing a computer generated topographic map of foliage covered terrain comprising the steps of overflying the terrain along a flight path, directing at the terrain while traversing the flight path a first radar pulse at a first frequency and a second radar pulse at a second frequency that is greater than the first frequency so as to produce a plurality of first signals representative of the distance from points along the flight path to the terrain surface and a plurality of second signals representative of the distance from points along the flight path to the foliage surface, measuring the distance of the points along the flight path above a preselected reference plane to derive plural altitude signals, generating location coordinate signals representative of the location of the points along the flight path relative to the terrain, producing a continuous series of timing pulses recurring at preselected time intervals for affording correlation with the points along the path, simultaneously recording the first, second, altitude and coordinate signals and timing pulses on a recording medium measuring temperature and pressure on the terrain surface to produce a ground temperature signal and a ground pressure signal, and recording the ground temperature signal and the ground pressure signal with a standard time signal to afford subsequent input of the data on the recording medium and the ground temperature and pressure signals to a computer in time correlation for generation of a topographic map of the terrain.