Measurement of the local dark matter density plays an important role in both Galactic dynamics and dark matter direct detection experiments .
However , the estimated values from previous works are far from agreeing with each other .
In this work , we provide a well-defined observed sample with 1427 G & K type main-sequence stars from the LAMOST spectroscopic survey , taking into account selection effects , volume completeness , and the stellar populations .
We apply a vertical Jeans equation method containing a single exponential stellar disk , a razor thin gas disk , and a constant dark matter density distribution to the sample , and obtain a total surface mass density of 78.7 ^ { +3.9 } _ { -4.7 } M _ { \odot } pc ^ { -2 } up to 1 kpc and a local dark matter density of 0.0159 ^ { +0.0047 } _ { -0.0057 } M _ { \odot } pc ^ { -3 } .
We find that the sampling density ( i.e .
number of stars per unit volume ) of the spectroscopic data contributes to about two-thirds of the uncertainty in the estimated values .
We discuss the effect of the tilt term in the Jeans equation and find it has little impact on our measurement .
Other issues , such as a non-equilibrium component due to perturbations and contamination by the thick disk population , are also discussed .