Measurements of the Zodiacal Light Absolute Intensity through Fraunhofer
  Absorption Line Spectroscopy with CIBER
  Scattered sunlight from the interplanetary dust (IPD) cloud in our Solar
system presents a serious foreground challenge for spectro-photometric
measurements of the Extragalactic Background Light (EBL). In this work, we
report on measurements of the absolute intensity of the Zodiacal Light (ZL)
using the novel technique of Fraunhofer line spectroscopy on the deepest 8542
Angstrom line of the near-infrared CaII absorption triplet. The measurements
are performed with the Narrow Band Spectrometer (NBS) aboard the Cosmic
Infrared Background Experiment (CIBER) sounding rocket instrument. We use the
NBS data to test the accuracy of two ZL models widely cited in the literature;
the Kelsall and Wright models, which have been used in foreground removal
analyses that produce high and low EBL results respectively. We find a mean
reduced chi squared of 3.5 for the Kelsall model and a chi squared of 2.0 for
the Wright model. The best description of our data is provided by a simple
modification to the Kelsall model which includes a free ZL offset parameter.
This adjusted model describes the data with a reduced chi squared of 1.5 and
yields an inferred offset amplitude of 46 +- 19 nW m^-2 sr^-1 extrapolated to
12500 Angstroms. These measurements elude to the potential existence of a dust
cloud component in the inner Solar system whose intensity does not strongly
modulate with the Earth's motion around the Sun.
