  The CAMbridge Emission Line Surveyor (CAMELS) is a pathfinder program to
demonstrate on-chip spectrometry at millimetre wavelengths. CAMELS will observe
at frequencies from 103-114.7 GHz, providing 512 channels with a spectral
resolution of R = 3000. In this paper we describe the science goals of CAMELS,
the current system level design for the instrument and the work we are doing on
the detailed designs of the individual components. In addition, we will discuss
our efforts to understand the impact that the design and calibration of the
filter bank on astronomical performance. The shape of the filter channels, the
degree of overlap and the nature of the noise all effect how well the
parameters of a spectral line can be recovered. We have developed a new and
rigorous method for analysing performance, based on the concept of Fisher
information. This can in be turn coupled to a detailed model of the science
case, allowing design trade-offs to be properly investigated.
