15 July 2002
J
H
K
Ks
Zeropoint
(mag per 1 ADU/s)23.4
23.4
-
22.9
Background brightness
(mag/sqr-arcsec)15.7-16.4
13.7-14.6
-
11.9-12.0
Extinction constant
(mag/airmass)0.10
0.05
-
0.12
4 July 2001
Zeropoint
(mag per 1 ADU/s)23.5
23.6
23.0
-
Background brightness
(mag/sqr-arcsec)15.4-16.1
13.5-14.6
11.7-11.9
-
Extinction constant
(mag/airmass)0.07
0.12
0.11
-
1 April 2001
Zeropoint at 1.0 airmass
(mag per 1 ADU/s)23.4
23.4
22.8
22.7
Background brightness
(mag/sqr-arcsec)16.1
14.7
12.1
12.5
Extinction constant
(mag/airmass)-
-
-
-
