Instrument Overview
  ===================
 
  The Total Luminance Photometer (TLP) provides visible light
  intensity data of the crater flash event.  The TLP instrument
  consists of two elements: the Sensor Electronics Module (SEM)
  which contains the optics and sensor assembly and signal
  filtering, and the Digital Electronics Module (DEM), which
  converts the analog sensor signal to a digital output and formats
  this for transmission to the DHU.  The DEM is a commercial
  microprocessor package that was customized for LCROSS.  This
  instrument is designed and manufactured by NASA Ames Research Center.
 
  The TLP instrument's single-element visible light detector is
  designed to operate at 1000 Hz to make a high fidelity record of
  the impact flash.  The optics in the SEM delivers an unobstructed
  ~10 degree field-of-view.  The TLP's sensor element is an uncooled
  Advanced Photonix, Inc. (API) avalanche photo diode (APD) packaged
  in a dry-air sensor container that can operate in a vacuum.
 
  The TLP SEM, located within the Payload Observation Deck (POD), is
  connected by an electrical harness to the TLP DEM, located at a second
  position on the payload panel. The DEM is interfaced with the DHU
  via a second cable, from which is it controlled.
 
  The SEM and DEM's peak power during operation are 2.5 and 12.0W,
  respectively.
 
  Scientific Objectives
  =====================
 
  The total luminance photometer, operating at a 1 kHz sampling
  rate, provides temporal and total radiance coverage (in the
  visible band) of the impact flash event, expected to last a few
  milliseconds.
 
  At the Centaur impact, the kinetic energy of the projectile is
  transferred to the kinetic (ejecta) and internal energy the target
  (compaction, heating).  A portion of the internal energy may
  induce vapor resulting in vibrational and rotational emission
  lines that will evolve with space and time.  The intensity and
  decay of the initial flash are related to the porosity, strength,
  volatile content, and composition of the target.  Consequently,
  characterization of the initial flash provides a complementary
  tool to understand initial energy coupling and the nature of the
  target.
 
  Calibration
  ===========
 
  The TLP has a spectral response range from 400 to 1000 nm.  A
  conversion from DN to integrated power (in Watts), defined as an
  algorithm, based on laboratory test data using simulated flash
  spectral fluxes and colors, is summarized in the Instrument
  Response and Calibration Report.  Ancillary data, such as the SEM
  sensor temperature profile, is needed to provide the necessary
  temperature-dependent gain corrections. This algorithm depends on
  the detection of the flash event above the background, As this was
  not detected, the algorithm was not applied to the raw data.  As a
  result, there are no calibration files associated with this
  instrument.
 
  Operational Modes
  =================
 
  There is a single operational mode for the total luminance
  photometer (TLP).
 
  The TLP is configured only to provide data for the 20 minutes
  prior to the Centaur impact (to provide for sufficient time for
  settling, which can affect data ~7-9 minutes after power on)
  through the flash (impact) and curtain (next 3 minutes) evolution
  of the experiment. The TLP is not baselined to be used during any
  of the other segments of the mission.