Combining measurements from different sensors

A method of measuring a parameter comprising using a suitably programmed computer to perform steps including:

• predicting a value of each of two independent measurements of the parameter for two independent measurement channels, making two independent measurements of the parameter via said two independent measurement channels to produce two measured values of the parameter, calculating respective differences between the predicted values and the measured values for each of said two independent measurement channels, combining the two measured values with weights determined by said respective differences to produce a combined value M, and outputting the combined value to a user, wherein the two measured values are combined according to the formula:—
• M
• =
• M
• 1
• ⁢
• σ
• 2
• 2
• σ
• 1
• 2
• +
• σ
• 2
• 2
• +
• M
• 2
• ⁢
• σ
• 1
• 2
• σ
• 1
• 2
• +
• σ
• 2
• 2
• where M1 and M2 are the two measured values, and σ1 and σ2 are differences between the two measured values and their respective predicted values.

A method of measuring a parameter comprising using a suitably programmed computer to perform steps including:

• predicting a value of each of two independent measurements of the parameter for two independent measurement channels;
• making two independent measurements of the parameter via said two independent measurement channels to produce two measured current values of the parameter;
• calculating respective differences between the predicted values and the measured current values for each of said two independent measurement channels;
• and
• combining the two measured current values with weights which vary inversely with said respective differences to produce and output to a user a measurement of the parameter which is based on the two measured current values.

A method of measuring a parameter comprising using a suitably programmed computer to perform steps including:

• predicting a value of each of two independent measurements of the parameter for two independent measurement channels;
• making two independent measurements of the parameter via said two independent measurement channels to produce two measured current values of the parameter;
• calculating respective differences between the predicted values and the measured current values for each of said two independent measurement channels;
• combining the two measured current values with weights which vary inversely with said respective differences to produce a measurement of the parameter which is based on the two measured current values;
• and
• displaying the measurement of the parameter.