1. NITEOWL Science
1.1 Science
1.2 Experiment
1.2.1 Broad Design
	The NITEOWL experiment is to be launched from Churchill, MB aboard a “Orion” rocket. This 
rocket will take the experiment to an altitude of 80km.  From apogee the experiment will fall to earth 
beneath a specially constructed parachute.  As the payload falls measurements allowing the calculation of 
the abundance of ozone will be taken using an optical spectrograph.  The position of the rocket and 
instrument will be monitored using a (GPS) Global Positioning System.  This will be used both to track 
the altitude of the instrument and to enable recovery of the payload after the experiment.  There will be 
two data streams sent from the NITEOWL experiment to receiving equipment on the ground.  A block 
diagram of the entire instrument is shown in Figure 1-1.

 
Figure 1-1 Block Diagram of the NITEOWL Experiment
	The spectrograph will measure the intensity of incident starlight after it has been attenuated by 
the atmosphere and dispersed using a diffraction grating.  The dispersed and attenuated light will be 
focused on a CCD (Charge Coupled Device) detector.  The spectral resolution of the data collected by the 
CCD will be 5 nm with a total wavelength range of 400 nm ranging over the Chappuis band from 400 to 
800 nm.  The CCD detector readout will be sent to the on-board data compression system which will take 
incoming data from both the GPS and the detector and pass all of the information to the telemetry system 
which will transmit the data to a receiving system on the ground.
	The attitude video camera is a CCD camera which has a wider field of view than the optical 
system and is used to determine the pointing direction of the optical system.  This camera transmits the 
images it receives down to the data processing equipment on the ground on a separate frequency.
	The first section below describes the methods which will be used to aquire and analyse the data 
aquired by the optical system.  The instrumentation used is described in more detail in section 1.2.3.  
Section 1.2.4 describes the resolution and confidence which are expected to be obtained for the ozone 
concentration profile.  Last the zeroth level data processing and ground-based validation which will be 
discussed.
1.2.2 Description of Experimental Methods

1.2.3 Instruments
	The starlight from a field of view which subtends 15 degrees horizontally and 7.5 degrees 
vertically will be imaged by the optical system on the CCD detector.  This starlight is assumed to be 
emitted by point sources and to arrive at the entrance to the optical system collimated.  The first element 
in the optical system is a transmission grating which diperses the collimated light which is incident from 
the stars in the field of view.  This dispersed light is then focused on the CCD detector by an objective 
lens.  These two elements are chosen such that the dispersion of the incoming light by the transmission 
grating allows the objective lens to project an image onto the CCD detector such that 5 nm of the 
spectrum covers a single pixel of the CCD detector.
	The global positioning system is to be provided by Bristol aerospace as an integrated portion of 
the orion rocket telemetry system.  This system should allow tracking of the experiment with a precision 
of up to 100 m.
	The attitude video camera will be a camera with a CCD detector with a wide enough field of view 
and a high enough sensitivity that one can be assured of enough stars being in the field of view at all times 
to be able to determine the pointing direction of the optical system.  This type of system has been used on 
both Gemini and oedipus-c missions.
1.2.4 Expected Performance
1.2.5 Analysis and Ground-based validation