Recent analyses of laser data for determining variation of latitude have been based on apparent variations in the orbital inclination of the satellite derived from short orbital arcs of 6--8 hours. An alternative method, based on the daily adjustment of the station position to a much longer arc of 2 or 3 weeks has recently been developed and tested. In the new method a long orbital arc is derived from many days of data and is subsequently used as a reference orbit for the adjustment of the position of the station (only) on each day of the long arc for which traking data are available. This new technique appears to give slightly better results when it is applied to a test period in August 9170, with the added advantage that earth rotation measurements can be derived from te same data at the same time. The results for the test period indicate a precision of 74 cm in variation of latitude and 0.81 ms in monitoring the earth's rotation with 6 hours of data.