Calibration techniques for next-generation astronomical systems

Historically, few astronomical measurements have required sub-percent accuracy in photometry. Measuring SNIa fluxes in order to determine cosmological parameters, however, often requires the comparison of images from different telescopes, and at different redshifts. This can introduce a myriad of sources of error. Conventional methods of data reduction are intrinsically flawed, either making assumptions about the effects of wavelength dependence in the response function of the system or, when K-corrections are not performed, neglecting them altogether. We consider the advantages of a method utilizing a direct, spectrally-resolved measurement of the entire system's response function relative to a calibrated photodiode.