Using data from the Sloan Digital Sky Survey Early Data Release and SuperCOSMOS Sky Survey scans of POSS-I plates , we identify a sample of \sim 2600 subdwarfs using reduced proper motion methods and strict selection criteria .
This forms one of the largest and most reliable samples of candidate subdwarfs known , and enables us to determine accurate luminosity functions along many different lines of sight .
We derive the subdwarf luminosity function with unprecedented accuracy to M _ { V } \la 12.5 , finding good agreement with recent local estimates but discrepancy with results for the more distant spheroid .
This provides further evidence that the inner and outer parts of the stellar halo can not be described by a single density distribution .
We also find that the form of the inner spheroid density profile within heliocentric distances of 2.5 kpc is closely matched by a power law with an index of \alpha = -3.15 \pm 0.3 .