عنوان مقاله [English]
نویسنده [English]چکیده [English]
So far, the least squares adjustment principles have been described in detail in textbooks and in papers in numerous journals. This function (title of the paper) is related to the common least squares adjustment, in which a set of observations are simultaneously processed and a certain estimation of the unknown parameters is obtained (assuming that all necessary observations have
been collected and are free from mistakes).
This is the case is in most adjustments. However, sometimes we may not be able to provide all observations at one time, or we might want to carry out adjustment by only a small set of observations and then, if necessary, remove or add observations in order to best estimate the unknown parameters. If we repeat whole the adjustment every time we replace observations, we waste time and energy. The effect of adding or removing observations can be determined by step-by-step method of adjustment. This operation can also greatly reduce the amount of computer memory needed to simultaneously process all the observations.