To implement this technology a reference unit was established that broadcasts both differential corrections in RTCM format (used by Black Thunder's truck monitoring system) and compact measurement (CMR2
) signals which provide RTK solutions.
OTHPP[S.sub.j] = j variables related only to PPS (see Table 1) and for which there are no pre-PPS equivalents; SEASON = dummy variables for fall, winter, spring; t = 1,..., 28, quarters from January 1980 through December 1986; CMRO = 1 for t = 1,...,11, 0 otherwise; CMR1 = 1 for t = 12,.., [t.sub.PPS-1], 0 otherwise; CMR2 = 1 for t = [t.sub.PPS],..., 28, 0 otherwise; and
(6.) The period of case-mix reimbursement includes not only the quarters that hospitals were subject to PPS (CMR2) but also the quarters during which they were reimbursed under TEFRA (CMRI).