Instead of users (e.g., independent owners/operators of different satellites) having to calculate orbit determination for each satellite themselves, an orbit determination service automatically calculates the orbit determination (OD) based on a user request. The calculated OD can then be used by a satellite ground station service to determine appropriate orientations for a ground station antenna in order to communicate with the satellite. In some embodiments, the OD service uses information from the calculations of ODs for multiple satellites and users to update a model used in the OD calculation, for example, to provide a more accurate model for Earth's atmosphere to be applied in subsequent OD calculations. In some embodiments, the OD service uses a user-provided computer-aided drawing (CAD) file of the satellite to produce or tune models specific to the satellite, for example, to generate more accurate models for solar radiation pressure and ballistic drag.

A method for accurately and efficiently calculating a dense ephemeris of a high-eccentricity orbit is provided. With respect to the ephemeris calculation of the high-eccentricity orbit, the method constructs uneven interpolation nodes through time transformation and interpolates by an interpolation polynomial based on uneven interpolation nodes to obtain a dense ephemeris, which significantly improves the calculation efficiency and accuracy. Based on a large-scale numerical experiment, the method derives an optimal universal value (that is, 0.3) of a transformation parameter for all orbital eccentricities and various interpolation polynomials. In the case of using the optimal universal value of the transformation parameter δ, the method further verifies the Hermite interpolation polynomial as the preferable one among various interpolation polynomials.

A satellite constellation forming system (100) forms a satellite constellation (20). The satellite constellation (20) is composed of a satellite group (300). In the satellite constellation (20), the satellite group (300) provides a service cooperatively. The satellite constellation (20) has a plurality of orbital planes in which a plurality of satellites (30) fly at the same orbital altitude in each orbital plane (21). A satellite constellation forming unit (110) forms the satellite constellation (20) in which orbital altitudes of the plurality of orbital planes (21) are mutually different.

A satellite constellation forming system (100) forms a satellite constellation (20). The satellite constellation (20) is composed of a satellite group (300). In the satellite constellation (20), the satellite group (300) provides a service cooperatively. The satellite constellation (20) has a plurality of orbital planes in which a plurality of satellites (30) fly at the same orbital altitude in each orbital plane (21). A satellite constellation forming unit (110) forms the satellite constellation (20) in which orbital altitudes of the plurality of orbital planes (21) are mutually different.

The present disclosure relates to an upper-atmospheric mass density prediction model with robust and reliable uncertainty estimates in accordance with various embodiments of the present disclosure. The upper-atmospheric mass density model is developed based on the SET HASDM density database. In various embodiments, PCA is used to reduce the spatial dimension of the dataset. The input sets used to train the mass density model contains a time series for the geomagnetic indices. The mass density prediction model is trained to output a mass density map for accurately prediction trajectories of satellites. For example, a likelihood of collision associated with a given object can be determined based at least in part on the mass density map. Analysis of the mass density map along with the likelihood of collision can used to determine a trajectory for the given object in space.

A system for identifying a target object includes a database containing a plurality of unique combinations of a plurality of orbital angular momentum modes. Each of the unique combinations of the plurality of orbital angular momentum modes is associated with a particular type of target object. A signal generator generates a signal having one of a plurality of orbital angular momentum modes applied thereto and directs the signal toward the target object. A transceiver transmits the signal toward the target object and receives a second signal having a unique combination of a plurality of orbital angular momentum modes reflected from the target object. A detection system compares the second signal having the unique combination of the plurality of orbital angular momentum modes with the plurality of unique combinations of the plurality of unique orbital angular unique combination of a plurality of orbital angular momentum modes within the database, identifies the target object responsive to the comparison of the second signal having the unique combination of the plurality of orbital angular momentum modes with the plurality of unique combinations of the plurality of unique orbital angular unique combination of a plurality of orbital angular momentum modes within the database and provides an output identifying the target object.

A system and method of tracking a hypersonic object over a flightpath includes at least one observer having at least one sensor. The sensor is configured to provide measurements of the hypersonic object that are geometrically diverse such that each observer may independently measure any combination of range, angles, Doppler, and angle rates. The observers transmit measurements to a processing unit as the hypersonic object undergoes three phases including a boost phase, a ballistic phase, and a hypersonic glide phase. The hypersonic object is tracked over many time steps by first selecting a dynamics model representative of expected object kinematics during said phase. Then, an unscented Kalman filter is used to predict a future state and a covariance using the dynamics model that was selected. Finally, the unscented Kalman filter updates the future state and covariance that were predicted based on the geometrically diverse measurements of the sensors.

A method for estimating a right-under point position of an on-orbit object includes an imaging step of capturing an observation image of an on-orbit object, together with a known object of which an orbit is known, a first right-under point position calculation step of calculating a right-under point position with respect to a center point of the observation image, and a second right-under point position calculation step of calculating a right-under point position of the on-orbit object based on the right-under point position with respect to the center point of the observation image.

A method for estimating a right-under point position of an on-orbit object includes an imaging step of capturing an observation image of an on-orbit object, together with a known object of which an orbit is known, a first right-under point position calculation step of calculating a right-under point position with respect to a center point of the observation image, and a second right-under point position calculation step of calculating a right-under point position of the on-orbit object based on the right-under point position with respect to the center point of the observation image.

The focus of the present disclosure relates to a constellation of earth-observation satellites communicating with terrestrial access points through an intermediate satellite constellation of networked relay satellites. The network system includes one or more terrestrial access points, one or more earth observation satellites, and a satellite constellation including a plurality of communicatively coupled relay satellites. The earth observation satellites establish links with the relay satellites, which relay the communications from the earth observation satellites to the terrestrial access points. The earth observation satellite can transfer recorded information to one or more of the plurality of relay satellites. The communication from the earth observation satellite may be routed through multiple relay satellite in the network system to reach the terrestrial access point. Rather than transferring information from an earth observation satellite only when the earth observation satellite passes over the terrestrial access point, the network disclosed enables earth observation satellites to transfer information through the intermediate satellite constellation quickly and securely from nearly anywhere along its orbit around the Earth. Because the Earth observation satellite can route recorded information through the plurality of satellites in the intermediate satellite constellation to a terrestrial access point, instead of only when the earth observation satellite travels within range of a single terrestrial access point, the disclosed network system significantly extends the data transfer window while reducing monitoring delays.