The following calibration format can be used directly in 
IRAF.digiphot.photcal.invertfit. The instrumental magnitudes
mU, mB, and mV are -2.5*log(counts/s)+25.

For the these images, the average parameters for UBV are the following:
Airmass---1.40, 1.09, 1.08
Integration time (s)---1800, 1800, 1200
Pixel scale (arcsec)---1.134, 1.134, 1.134

# Thu 15:08:01 30-May-2002
begin	BFIT
	status	0	(Solution converged)
	variance	0.001936667
	stdeviation	0.04400757
	avsqerror	0.002694207
	averror		0.05190575
	avsqscatter	9.749284E-4
	avscatter	0.03122384
	chisqr		0.7188261
	msq		0.001852464
	rms		0.04304026
	reference	mB
	fitting		(BV+V)+b1+b2*XB+b3*BV+b4*BV*XB
	weights		photometric
	parameters	4
		b1	(constant)
		b2	(fit)
		b3	(constant)
		b4	(constant)
	derivatives	4
		0.1
		0.1
		0.1
		0.1
	values	4
		3.445
		0.2373955
		-0.022
		0.
	errors	4
		0.
		0.004757675
		0.
		0.

# Thu 15:15:01 30-May-2002
begin	VFIT
	status	0	(Solution converged)
	variance	5.933754E-4
	stdeviation	0.0243593
	avsqerror	5.916241E-4
	averror		0.02432332
	avsqscatter	3.546218E-4
	avscatter	0.0188314
	chisqr		1.00296
	msq		5.777603E-4
	rms		0.02403664
	reference	mV
	fitting		V+v1+v2*XV+v3*BV+v4*BV*XV
	weights		photometric
	parameters	4
		v1	(constant)
		v2	(fit)
		v3	(constant)
		v4	(constant)
	derivatives	4
		0.1
		0.1
		0.1
		0.1
	values	4
		3.017
		0.1511767
		0.045
		0.
	errors	4
		0.
		0.002345854
		0.
		0.

# Thu 14:41:09 11-Jul-2002
begin	UFIT
	status	0	(Solution converged)
	variance	0.003643455
	stdeviation	0.06036104
	avsqerror	0.003641509
	averror		0.06034491
	avsqscatter	0.002788662
	avscatter	0.05280778
	chisqr		1.000534
	msq		0.00355459
	rms		0.05962038
	reference	mU
	fitting		(UB+BV+V)+u1+u2*XU+u3*BV+u4*UB*XU
	weights		photometric
	parameters	4
		u1	(fit)
		u2	(constant)
		u3	(constant)
		u4	(constant)
	derivatives	4
		0.1
		0.1
		0.1
		0.1
	values	4
		5.065
		0.515
		-0.146
		0.
	errors	4
		0.006
		0.
		0.
		0.