  Although quantum metrology allows us to make precision measurement beyond the
standard quantum limit, it mostly works on the measurement of only one
observable due to Heisenberg uncertainty relation on the measurement precision
of non-commuting observables for one system. In this paper, we study the
schemes of joint measurement of multiple observables which do not commute with
each other by using the quantum entanglement between two systems. We focus on
analyzing the performance of newly developed SU(1,1) interferometer on
fulfilling the task of joint measurement. The results show that the information
encoded in multiple non-commuting observables on an optical field can be
simultaneously measured with a signal-to-noise ratio higher than the standard
quantum limit, and the ultimate limit of each observable is still the
Heisenberg limit. Moreover, we find a resource conservation rule for the joint
measurement.
