The u'g'r'i'z' Standard Star System -- USNO40 Response Function
USNO40 Filter Transmission Curves
The u'g'r'i'z' filters used on the USNO 40-in telescope at Flagstaff Station, Arizona,
were manufactured by Asahi Spectra Co. Ltd. in Japan according to the specifications
Here, we present the tabulated transmission curves for each filter, which were measured
in 1995 by the
SDSS Japan Participation Group (JPG):
3-inch filters for USNO
USNO40 Response Functions
These files were created by Jim Gunn and are response (QE) functions
for the USNO 40-inch/SITe 1024^2 UV-coated CCD as best as is
understood at this point (011218). The z' functions are quite
uncertain, as we have no measurements of the USNO CCD at all; though
the response through the visible and even into the uv is quite
constant from device to device, the far IR response is quite variable.
The QEs have been corrected for IR scattering and are the appropriate
responses for point sources, NOT extended objects. These corrections
are probably as uncertain as the underlying response is.
For more details, consult this README file.
As better measurements of the USNO40 response functions are
determined, they will be placed on this website.
USNO40 Response Curves
Last modified: Thu Feb 26 15:30:14 CST 2004