technically, WMD7 can stable to anywhere, if its INS know where to look.
that's why it can be slaved to SPI.
we think stable to a coord many many miles away in SP mode, is a bit like black magic.
stable to ground in SP mode need precice coord, this coord need laser ranger in effect range.
this limit can be extended after we bring radar AGR online.
we dont want to rely on digital map too much. :)