Geooptics, Inc.

The United States of America As Represented by the Administrator of the

Thomas Patrick Yunck

William I Bertiger

Stephen M Lichten

Anthony J Mannucci

Sien-Chong Wu

Ronald J Muellerschoen

A constellation of satellites and associated methods for Earth Observation are disclosed. One method includes transmitting a set of at least four signals towards the Earth using a constellation of at least four satellites and receiving a set of at least four reflected signals from the Earth using the constellation. The method also includes analyzing, using a set of at least four signal analyzers, the set of at least four signals to generate a set of data. Each satellite in the constellation individually houses a signal analyzer in the set of at least four signal analyzers. The method also includes deriving the set of Earth observations using the set of data. Each satellite receives a signal in the set of at least four signals from every other satellite in the constellation.

Symmetrical multistatic radar constellation for earth observation

A fleet of small spacecraft ('cells') in low Earth orbit combine to form an integrated Earth observing system providing many observations previously requiring distinct sensing systems. Each cell performs a few relatively primitive functions, including emission, reception, sampling, and recording of radio and microwave signals. Each cell observes over a spherical field of view, samples the received signals independently at many small antenna elements, and stores the data from each element. Data from all cells are sent to a common location where they can be combined in diverse ways to realize a wide range of observing functions. These functions may include ionosphere and gravity field mapping; atmospheric radio occultation; ocean, ice, and land altimetry; ocean scatterometry; synthetic aperture radar (SAR) imaging; radar sensing of soil moisture, land cover, and geological surface properties; and interferometric SAR sensing of surface change. The system can also provide real-time messaging, navigation and surveillance functions.

Cellular interferometer for continuous Earth remote observation (CICERO) satellite

Cellular interferometer for continuous earth remote observation (CICERO)

The present invention provides a method and a device for providing superior differential GPS positioning data. The system includes a group of GPS receiving ground stations covering a wide area of the Earth's surface. Unlike other differential GPS systems wherein the known position of each ground station is used to geometrically compute an ephemeris for each GPS satellite, the present system utilizes real-time computation of satellite orbits based on GPS data received from fixed ground stations through a Kalman-type filter/smoother whose output adjusts a real-time orbital model. The orbital model produces and outputs orbital corrections allowing satellite ephemerides to be known with considerable greater accuracy than from the GPS system broadcasts. The modeled orbits are propagated ahead in time and differenced with actual pseudorange data to compute clock offsets at rapid intervals to compensate for SA clock dither. The orbital and clock calculations are based on dual frequency GPS data which allow computation of estimated signal delay at each ionospheric point. These delay data are used in real-time to construct and update an ionospheric shell map of total electron content which is output as part of the orbital correction data, thereby allowing single frequency users to estimate ionospheric delay with an accuracy approaching that of dual frequency users.

Robust real-time wide-area differential GPS navigation

Growing community of inventors

Pasadena, CA, United States of America

Thomas Patrick Yunck