USNO Magnitudes versus calibrated

Field RA = 18h01.8m DC = +07°02'

Fig 1. USNO 'B' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = +1.83 -0.129 * B_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'B' = +0.02
Error cancels for Magnitude 14.2

Fig 2. USNO 'R' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = +1.12 -0.080 * R_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'R' = 0.00
Error cancels for Magnitude 14.0

For any comment, contact Jean-Claude PELLE