Systems and methods are provided for scheduling objects having pair-wise and cumulative constraints. The systems and methods presented can utilize a directed acyclic graph to increase or maximize a utilization function. The objects can comprise satellites in a constellation of satellites. In some implementations, the satellites are imaging satellites, and the systems and methods for scheduling can use human collaboration to determine events of interest for acquisition of images. In some implementations, dominant edges are removed from the directed acyclic graph. In some implementations, dynamic weights are assigned to nodes associated with downlink events in the directed acyclic graph.

Methods and apparatus for Real-time Satellite Imaging System (10) are disclosed. More particularly, one embodiment of the present invention an imaging sensor (14) on a geostationary satellite having one or more co-collimated telescopes (18). The telescopes (18) illuminate local planes (22) which are sparsely populated with focal plane arrays (24). The focal plane arrays (24) record the entire observable Earth hemisphere at one time, at least once every ten seconds.

Systems and methods are provided for scheduling objects having pair-wise and cumulative constraints. The systems and methods presented can utilize a directed acyclic graph to increase or maximize a utilization function. The objects can comprise satellites in a constellation of satellites. In some implementations, the satellites are imaging satellites, and the systems and methods for scheduling can use human collaboration to determine events of interest for acquisition of images. In some implementations, dominant edges are removed from the directed acyclic graph. In some implementations, dynamic weights are assigned to nodes associated with downlink events in the directed acyclic graph.

A target tracking device to estimate a position of a target with high accuracy will be provided. The target tracking device is provided with a communication device and a processor. The communication device performs communication with a plurality of observation satellites that observe the target. The processor executes a selection of satellites, a setting of a schedule and an estimation. The selection of satellites includes selecting two or more selected satellites that observes the target among the plurality of observation satellites. The setting of the schedule includes determining an observation schedule for each of the two or more selected satellite to observe the target and transmitting an observation request signal that represents the determined observation schedule to a corresponding selected satellite. The estimation includes estimating the position of the target based on two or more pieces of high-precision observation information respectively observed by the two or more selected satellites.

A system and method of operating a focal plane array of a camera assembly for a space vehicle in orbit includes scanning across a scene containing a target surface using the focal plane array, generating a plurality of sampled signals for the scene using a plurality of detectors of the focal plane array, co-adding the sampled signals to produce an output having a constant spatial resolution, and correcting a temporal shift in a line-of-sight of the focal plane array by rotating the space vehicle or the camera assembly to null relative motion at a center point of a scan.

A satellite observation system and method of deploying a satellite system are disclosed. The system includes a plurality of observation satellites comprising one or more sensors, each of the plurality of observation satellites configured with at least a solar array and a mechanical stabilization element. Each of the plurality of observation satellites is constructed without positioning components. The plurality of observation satellites is positioned in a dawn/dusk sun-synchronous orbital plane about a celestial body such that the one or more observation sensors are oriented toward the celestial body. The system further includes one or more servicing vehicles configured to engage each of the plurality observational satellites to configure at least the solar array and mechanical stabilization element

A method (100) for referencing an optical image (19) including: obtaining (110, 120) a stereoscopic image pair (19, 23) of the optical image (19) and a SAR image (35), the surface areas covered by the images (19, 23, 35) on the ground having an overlapping area (39); selecting (130) an area of interest (42) in the overlapping area (39); from the area of interest (42): obtaining (140) a 3D model (40); calculating (150) a simulated radar image (44); estimating (160) an offset (di, dj) between the simulated image (44) and the radar image (35); selecting (170) a reference point (46); projecting (180) and shifting (di, dj) the reference point (46) in the radar image (35) to correct the radar connection point (46′″); determining (175) a pair of connection points (46′, 46″) in the image pair; and referencing the optical image (19) based on the connection points (46′, 46″, 46′″).

A method of controlling a satellite and a computer-readable recording medium are provided. The method is for controlling a satellite moving along an orbit having an inclination angle from the equatorial plane to capture due-north images. The method includes: determining a position of the satellite; calculating a roll angle and a pitch angle of the satellite for pointing a line-of-sight vector of the satellite to a first ground surface being a photographing point; determining a compensation angle by considering effects of the inclination angle and rotation of the Earth so as to capture images in the due north direction of the photographing point; calculating a yaw angle based on the compensation angle; and rotating the satellite according to the calculated roll angle, pitch angle, and yaw angle.

A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

A device for determining an attitude of a satellite is disclosed, the satellite having an attitude control system comprising a gyroscopic actuator including a flywheel mounted so as to be rotatable around an axis of rotation and carried by a gimbal articulated to rotate around an axis of rotation. The device includes an attitude sensor configured to measure the attitude of the satellite, a position sensor configured to measure the angular position of the gimbal around its axis of rotation, a speed sensor configured to measure the rotational speed of the flywheel, and a processing circuit configured to determine the attitude of the satellite by using the measurement of the angular position of the gimbal, the measurement of the rotational speed of the flywheel, and the measurement of the attitude of the satellite.