A Branch and Bound Algorithm for Agile Earth Observation Satellite Scheduling

Algorithm 2

The branch and bound algorithm.

Input: // the target list

// the initial attitude state of the satellite

// the current sequence solution

// the extending order of the targets

// the current best sequence solution

// the current best profit

// the number of look-ahead targets

Output: // the optimal sequence solution

// the optimal profit

(1)

(2) //Initialization

(3)

(4);

(5)

(6);

(7); // Computing the current profit

(8)

(9); ; //Updating the current best plan

(10)

(11)

(12); // Selecting the targets which still

have a visible time window

(13)

(14) if is not a consistent solution

(15)

(16)

(17)

(18)

(19)

(20); // Computing the upper bound

(21)

(22); // Backtracking if the upper bound of current solution is less than

(23)

(24)

(25) //Updating the current best solution

(26);

(27)

(28); // Determining the number of targets that

have not been tried

(29)for to numOfNext

(30);

(31)

(32)

(33);

(34)end if

(35)end if

(36);

(37);