公开(公告)号：US20230365276A1

公开(公告)日：2023-11-16

申请号：US18350862

申请日：2023-07-12

Applicant: KOREA ASTRONOMY AND SPACE SCIENCE INSTITUTE

Inventor： Eun Jung CHOI

IPC: B64G1/24 ,  G01C21/24 ,  B64G3/00

CPC classification number: B64G1/242 ,  B64G3/00 ,  G01C21/24

Abstract: A method of determining a precise orbit of a satellite through estimation of a parallactic refraction scale factor is proposed, the method includes inputting an initial estimate including initial orbit information of a satellite with respect to an observation epoch and the parallactic refraction scale factor; performing orbit propagation using a high-precision orbit propagator by applying a dynamics model; performing observer-centered satellite optical observation modeling including the parallactic refraction scale factor; calculating an observation residual between actual optical observation data and observation data calculated via the observation modeling reflecting the parallactic refraction; and precisely determining the orbit of the satellite by estimating the parallactic refraction scale factor and a satellite state vector using a batch least square estimation algorithm.

公开(公告)号：US20230348117A1

公开(公告)日：2023-11-02

申请号：US18350740

申请日：2023-07-11

Applicant: KOREA ASTRONOMY AND SPACE SCIENCE INSTITUTE

Inventor： Eun Jung CHOI

IPC: B64G3/00 ,  G06F17/17

CPC classification number: B64G3/00 ,  G06F17/175

Abstract: A method for re-entry prediction of an uncontrolled artificial space object includes: calculating an average semi-major axis and an argument of latitude by inputting two-line elements or osculating elements of an artificial space object at two different time points; calculating an average semi-major axis, argument of latitude, and atmospheric drag at a second time point; estimating an optimum drag scale factor while changing the drag scale factor; predicting the time and place of re-entry of an artificial space object into the atmosphere by applying the estimated drag scale factor. Here, orbit prediction is performed by using a Cowell's high-precision orbital propagator using numerical integration from the second time point to a re-entry time point.