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Phase I: FUV Internal/External Wavelength Scale Monitor

COS Cycle 18 Calibration - Phase I Template

Last Revised:	Oct 12 2010	Date
Proposal ID:	12425		(e.g. 9026)
Title: FUV Internal/External Wavelength Scale Monitor
PI: Cristina Oliveira	
Co-I(s):

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# Orbit estimates are TOTAL for all of cycle-10; assume 72 weeks) 

Total Prime Orbits:             6
External Parallel Orbits:       0
Internals or no-impact orbits:  0
Comments on orbit estimate:      1 orbit visits, observations spaced 
throughout the year, 3 orbits for M gratings, 3 orbits for L grating

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# This section should be written with a GO audience in mind -- use 
# Calibration plans in WFPC-2 handbook as a guide.

Purpose:     
This program monitors the offsets between the wavelength scale set by the 
internal wavecal versus that defined by absorption lines in external targets.
Description:  
    This program monitors the offset between the internal and external 
wavelength scales: this offset is referred to as "DELTA" in the wavelength dispersion reference file and corrects for the shift between the WCA and PSA in TV03 versus the shift between the WCA and PSA in orbit : (WCA-PSA_)_TV03 - (WCA - PSA)_orbit. Analysis of TV data indicates that this DELTA (offset) is cenwave and FPPOS independent for a particular grating, but it is grating and stripe dependent. To verify and monitor this, this program observes some cenwaves at different FPPOS.      
Accuracy:                       Uncertainties of the wavelength scales are given in table 4 of COS ISR 2010-06
Comments on Accuracy:           (How that accuracy is to be interpreted)
Products:                       
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# Link to Cycle 10 Science
# Use the GO + GTO Phase 1 exposure  listing and derived statistics
# posted on WWW.

Fraction of science programs supported by this calibration:    90% (by time, of all COS observations)

List categories of science which can't be executed until after this proposal: None
why: 

List categories of science which are best performed contemporaneous with 
this proposal: None
why:
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# THE REST OF THIS FORM IS FOR INTERNAL USE
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Observation summary: 
	(e.g. Take spectra of G191B2B at each supported central wavelength 
	 of each grating with the CCD and the 52x0.5 slit.) 

# Target information (copy for each target)

Target Name.............................: SK 191 (G130M and G160M) and NGC 330-B37 (G140L) 	
RA......................................: 01 41 42.0723 +/- 0.1" ; 00 56 20.7900  +/- 0.1"		
Dec.....................................: -73 50 38.20 +/- 0.1"	; -72 28 33.80  +/- 0.1"	
Flux (and units)........................: V=11.84; V=13.13	
Visibility window (if known or relevant):
Comment on choice of target:
*** See program 11997 (FUV wavelength monitoring in Cy 17) as the targets are the same ****

# Exposure list plan at the Phase I level. Be as complete as reasonable. 
# If possible information should be complete enough to allow easy 
# submission of a Phase 2 from this form. However, if you have to leave
# some of the fields blank below, or want to provide the information
# in another format, that is acceptable. (Make sure you do the BOP checking
# though, as this is a phase-1 issue.)

Table of exposures (copy for each exposure as appropriate/desired):

**** See VISIT 01 (SK191) and VISIT 02 (NGC330-B37) for information below; everything is the same as
in those visits except that the ACQ/SEARCH step is skipped because coordinates are well known.

Target or lamp..........................: e.g. G191B2B, or HITM
Type of Acquisition.....................: e.g. ACQ-PEAK
Detector for observation................: e.g. CCD
Operating mode .........................: e.g. ACCUM or TIMETAG
Spectral Element........................: e.g. G430L
Aperture................................: e.g. 50x0.5
Central Wavelength......................: e.g. 4300
Exposure Time...........................: e.g. 300s, crsplit=2 
Number of Iterations ...................: e.g. 1
BOP Predicted Local Count Rate for MAMA.:
BOP Predicted Global Count Rate for MAMA:
ETC PID IDs for Count Rates.............:
Special Requirements or options.........: (e.g. GAIN=4; LOW-SKY)
Comments: (e.g. if monitoring, specify frequency) 

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# Special needs of this proposal?

Scheduling: Visits will be scheduled throughput the year, at roughly 4 month intervals.

Prerequisites: (e.g., specific SMOV proposal; command development?)

PDB update?               (Specify table name if known e.g. SIAF).
On-board table update?    (Specify table name if known e.g. CCDBadPixelTable)

# Special Requirements:
Real time?                N
Special commanding?       N
Quick Data turnaround?    N
Special timing required?  N
Other?                    N
Describe (& justify) special requirements:


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# Analysis Plan

Expected FTE weeks for analysis:                                3
Required turnaround on analysis (weeks):                        0
Data volume (Mb needed for analysis):                           0
Special software needed for analysis? (Describe):

Description of analysis Plans:	(1-2 paragraphs): Centroids of absorption lines will be measured from the calibrated x1d files for the different epochs and compared between themselves, and with centroids determined from analysis of STIS data.