Self-aligning array of detector cells

A method for determining a flux of inspection radiation,

• wherein the inspection radiation is emitted by a radiation source and transmitted through cargo to inspect substantially in a transmission plane (YOZ),
• wherein the flux of inspection radiation is incident, after transmission through the cargo, on at least one array of detector cells extending in a plane substantially parallel to the transmission plane (YOZ), the array having a depth direction, and a longitudinal direction substantially perpendicular to the depth direction,
• the detector cells being configured in a first plurality L forming substantially rows of the array, each row of detector cells extending substantially along a direction parallel to the depth direction of the array,
• the detector cells being further configured in a second plurality 2 forming substantially at least two columns of the array, each column of detector cells extending substantially along a direction parallel to the longitudinal direction of the array,
• the method comprising:
• obtaining signal data Si′j′ associated with each detector cell of the array, each detector cell being located in (i′,j′) at an intersection of a column j′ and a row i′ of the array, the obtained signal data S for the array of detector cells being such that:
• S=F(I,R)
• with I being a flux assembly corresponding to the flux of the inspection radiation incident on the rows of the array,
• R being a contribution arrangement of coefficients Ri′j′i for the array of detector cells, representing a contribution of a beam of the inspection radiation, incident on row i such that 1≤i≤L, to the signal data Si′j′ of the detector cell located in (i′,j′) incident on the rows i of the array, and
• F being a known function of I and R;
• and
• determining the flux Ii of the inspection radiation incident on row i, for each row i such that 1≤i≤L, based on the obtained signal data Si′j′ and the coefficient Ri′j′ for each detector cell located in (i′,j′) at the intersection of the column j′ and the row i′ of the array.