M1=I1+I2
M2=I1
M3=I1-I3
M4=I1-I4
M5=I1+I2+I5
I1=M2
I2=M1-M2
I3=M2-M3
I4=M2-M4
I5=M5-M1
O1 = M1 + A0 + A1*I2 + A2*X + A3*T
O2 = M2 + B0 + B1*I2 + B2*X + B3*T
O3 = M3 + C0 + C1*I3 + C2*X + C3*T
O4 = M4 + D0 + D1*I4 + D2*X + D3*T
O5 = M5 + E0 + E1*I5 + E2*X + E3*T
A3=0. m:b,v,r,i,u
B3=0. i:V,B-V,V-R,V-I,U-B
C3=0.  
D3=0.
E3=0.
A0 =    1.9531    0.0038 <<    3.8   2  1.37 avg coeff n1,n2,n3 11/01 and
B0 =    1.6330    0.0029 <<   10.1   2  2.25  one night in 10/01 1.5m
C0 =    1.5867    0.0029 <<   23.3   2  3.41
D0 =    2.4463    0.0029 <<   13.5   2  2.60
E0 =    3.8095    0.0054 <<    7.0   2  1.87
A1 =    0.1114    0.0056 <<                  
B1 =   -0.0288    0.0032 <<
C1 =   -0.0090    0.0055 << 
D1 =   -0.0120    0.0032 <<
E1 =   -0.121     0.0096 << 
A2 =    0.2943    0.0148 <<    1.0   1  0.99  0.2324
B2 =    0.1353    0.0053 <<    0.0   1  0.18  0.1060
C2 =    0.0932    0.0070 <<    0.2   1  0.41  0.0800
D2 =    0.0535    0.0076 <<    1.1   1  1.06  0.0374
E2 =    0.46
S1 =   0.0132                << n1,n2,n3
S2 =   0.0075                << n1,n2,n3
S3 =   0.0000288             << n1,n2,n3
S4 =   0.0000096             << n1,n2,n3
S5 =   0.035                 << n1,n2,n3