## 3 Proposed Methods
### Reasoning-Based Scheduling Method
#### 3.2.1 Satellite State Prediction  
Satellite state prediction is the prediction of variables that reflect different coupled states of a satellite including the electrical energy, observation data volume, available downloading data volume, and occupied memory capacity. The satellite state prediction process consists of three predictions, which are the available observation target prediction, satellite occupied memory prediction, and satellite electrical energy prediction. Available targets \(\hat{x}_{i}\) are predicted through mission scheduling without data transmission and electricity constraints. The scheduling method refers to the maximum backward time slack heuristic [34; 35], and the calculation steps are shown in Appendix C. The total predicted observation data volume is expressed as  
\[\hat{M}_{intTotal}=\sum\hat{x}_{i}\Delta t_{o}R_{cam}. \tag{13}\]  
During the satellite Earth observation, the satellite's occupied memory capacity varies constantly. When the observation data are generated and stored, they occupy more memory capacity, instead, when the data are downloaded and deleted, the occupied memory can be released. It is necessary to divide the time segment and predict the occupied memory capacity of each time segment. Next, the entire scheduling period is divided into non-observation segments and observation segments. If there is a large time gap between two observations, this segment is regarded as the non-observation segment, which can be expressed as  
\[T_{uol}=\big{[}t_{oei_{r}}t_{osi_{i+1}}\big{]}\hskip 14.226378 pt\exists t_{osi_{i+1} }-t_{oei_{s}}\geq f_{A}\big{(}\mathbf{A}_{i_{s}},0\big{)}+f_{A}\big{(}0,\mathbf{A}_{i_{s +1}}\big{)},1\leq i\leq\hat{n}_{s}, \tag{14}\]  
where \(T_{uol}\) is the non-observation segment; \(l\) is the segment serial number; \(f_{A}\) is the satellite attitude maneuver angle calculation function; \(\hat{n}_{s}\) is the predicted number of selected targets; and \(\hat{s}_{i}\) is the target's serial number of the predicted observation result. In Equation (14), \(T_{uol}\) is the sufficient time interval between two observations that allows the satellite to switch to Earth-pointing mode. We set the union set of all non-observation segments as the set of non-observation segments \(T_{uo}=T_{u01}\cup T_{u02}\cup\ldots\cup T_{uon_{uo}}\), where \(n_{uo}\) is the number of non-observation segments. If the number of targets in a segment is large, that satellite will not switch to Earth-pointing mode during the observation process; this segment is defined as the observation segment. The observation segment set is the complementary set of the observation segment sets in the total scheduling period \(T_{o}=\mathbbm{C}_{T}T_{uo}\), where \(T=[t_{s},t_{e}]\) is the total scheduling period. In addition, the entire scheduling period was divided into data transmission segments and non-data transmission segments. We defined \(status^{i}_{datatrans}\) as whether target \(i\) is a favorable target for data transmission, which is represented as  
\[status^{i}_{datatrans}=\left\{ \begin{array}{cc}1&\exists t_{disk}\leq t\leq t _{gek},\mathbf{A}=\mathbf{A}_{0i},t=t_{ti}\\ -1&\textit{otherwise}\end{array} \right., \tag{15}\]  
where \(\mathbf{A}_{0i}\) is the satellite's attitude when observing the target \(i\) at the pitch angle of 0, and \(t_{ti}\) is the time when observing the target \(i\) at the pitch angle of 0. When the satellite is observing the target \(i\) with a pitch angle of 0 at the time \(t_{ti}\), we can determine whether the data transmission window constraint is met by determining whether there is a ground station within the satellite beam coverage. If such a ground station exists, target \(i\) is a favorable target for data transmission, otherwise, target \(i\) is an unfavorable target for data transmission. Next, we formed a union set of all data transmission time windows.