TIPS/JIM
August 18, 2011
Agenda:
INS Division News (Margaret Meixner)
Please Help Me! An Intro to the new HST Help Desk (Jennifer Mack)!
Signal to noise capabilities of COS if need be (Derck Massa)!
INS News
• Astro-statistics course: Sept-October, August 26, deadine for signup • Keswick building lease has been signed; Lennon is on housing committee;
current thinking are moves to occur summer 2012 to fall 2012
• In vacation season… & • Appraisal writing season
• Not to early to think about what you might
New INS arrivals:
• Janice Lee, Fall 2011, working with WFC3 team
• John Debes, will start Monday August 29, on COS/STIS team
Departures from INS:
• Parviz Ghavamin moved onto Towson University Faculty • Keith Noll, will depart in Fall 2011
Job advertisements in INS:
• RIA positions are advertised: see Aparna or Max • COS visiting Scientist position: See Ale
TIPS/JIM
August 18, 2011
Agenda:
INS Division News (Margaret Meixner)
Please Help Me! An Intro to the new HST Help Desk (Jennifer Mack)!
Signal to noise capabilities of COS if need be (Derck Massa)!
Please Help Me!
An Intro to the new Help Desk
TIPS: Aug 18, 2011
J. Mack
2011 STScI TransiCon ‐‐> Remedy (1990’s) to Footprints
4 Workspaces ‐ Help, Support, Archive, OPO
Organized via unique incoming email address
Separates different STScI enCCes
Operates independently of other workspaces
A composite of Cckets, contacts, knowledge bases, preferences
‘
Help@STScI
’
‐ TransiCon on June 15
th, 2011
‐ Support for Cycle 19 Phase II
Purpose:
Support the HST (and JWST) User Community
Importance of this Role:
Item #1 from the Director s Office Principles for STScI
The InsCtute was set up to provide long term guidance and support for the scienCfic effort, provide a mechanism for engaging the parCcipaCon of astronomers throughout the world, & provide a means for the disseminaCon and uClizaCon of the data
Access:
–
–
Web interface
haps://footprints.stsci.edu
Help ConfiguraCon and TesCng –
CollaboraCon across Divisions (INS, OED, SMO, ITSD) CollaboraCon across Missions (HST, JWST)
Help Workspace ‐ Supports 14 teams
– Triage level: Help – AcCve Instruments: ACS, COS, STIS, WFC3 – InacCve Instruments: FOS, GHRS, NICMOS, WFPC2 – Phase I/II support: APT, ETC, SMO – Soeware: SSB – Upcoming: JWST
Footprints Features
• Web‐based; Plahorm independent; Aaachments allowed • HST ProPer database populates user fields (Title, AffiliaCon, HST proposal IDs) • Auto‐noCficaCons (New or InacCve calls) – EscalaCons enable the automaCon of business • Auto‐generated reports (Triage= weekly, Team= monthly) – Emailed to teams for tracking development needs via call categories (i.e. soeware, documents, tools) • Searchable Knowledge base (Public vs. internal) – Repository for known issues, procedures, soluCons – Allows Cmely info and FAQs to be conveyed to users
GOAL: Develop experCse within the RIAB Provide mentoring, encourage learning process Minimize reliance on support from IS s SoluCon: New roles: Agent, Advisor, Expert No more weekly duty shies
– On arrival of new ticket, all agents are notified
– Individuals select tickets based on expertise or interest
GOAL:
Communicate user queries with Teams
Provide call category stats for enhancements
Give credit for the excellent work RIAs do supporCng users
SoluCon:
Monthly reports distributed to teams
Calls accessible to non‐agents via read‐only accounts
•
Agents:
RIAs trained to service Cckets via Footprints•
Advisors:
Expert level RIA/RIS Oversee team acCviCes Provide guidance to agents•
Experts:
IS/CS in team Replies to agent ‐or‐ Replies directly to the user (cc: help)User Support Roles
EscalaCon Rules ‐
Enable the automaCon of processes
In effect Mon‐Fri (9 am ‐ 5 pm) • Triage : Goal – route calls within 2 hours • Team : Goal – first response to user within 1 day Auto‐noCficaCon emails all agents: When NEW call arrives When no one has taken the call aeer 1 day Auto‐noCficaCon emails assignee: When call is IN PROGRESS and INACTIVE for 2 days When call is on HOLD and INACTIVE for 10 days (2 weeks) Auto‐noCficaCon emails supervisor : When team has not responded to call aeer 1 day When call is IN PROGRESS but INACTIVE for 3 daysReporCng
Count
Team
Read‐only Accounts
for INS Teams
Purpose: For IS, CS, or PC Enables team to view call resoluCon Provides call details for soeware/doc enhancements Access: Read‐only Can view all Cckets (i.e. ACS Team Calls) Can run reports (Tickets by category, by agent, etc) User ID s: awt_help cos_sCs_help wfc3_help Passwords: (To be emailed to each team)QuesCons?
•
Policy & Oversight (RIAB)
– Jennifer Mack ([email protected]) – Max Mutchler ([email protected])
•
AdministraCon & Training Needs
– Abhijith Rajan ([email protected]) – Brian York ([email protected])
TIPS/JIM
August 18, 2011
Agenda:
INS Division News (Margaret Meixner)
Please Help Me! An Intro to the new HST Help Desk (Jennifer Mack)!
Signal to noise capabilities of COS if need be (Derck Massa)!
COS signal to noise capabilities
Limitation of COS S/N
• No good 2-D flat available.• Fixed pattern noise dominates COS spectra.
An uncalibrated COS spectrum is affected by:
• Optical response• Smooth
• Fixed in wavelength space (sort of)
• Fixed pattern noise
• Due to detector irregularities
• Rapidly varying with detector position
• Fixed in detector space
Separating fixed pattern noise and spectrum:
• Iterative approachThe FP-POS Algorithm
Data taken at several, slightly shifted wavelengths
1. Align all of the spectra in λ space and create a meanspectrum (reduces fixed pattern noise by 1/√N).
2. Divide each spectrum by the mean and average the results in
detector space for an estimate of the fixed pattern noise. 3. Divide each spectrum by the fixed pattern noise estimate.
4. GOTO 1 and iterate “until done”.
Some limitations:
• Algorithm can get “confused” by busy spectra.
• COS FP-POS offsets are nearly identical, so some spatial
frequencies are poorly constrained.
Works well in many cases, but error estimates are
a bit sketchy.
A 1-D flat derived by the FP-POS algorithm, as implemented by Tom Ake for COS. Grid wire shadows are marked.
(Left) Net spectrum of WD0308-565 from FP-Split algorithm, binned by 3 pixels (half a RESOL). Also shown: 3 weak S II IS lines, and a quadratic fit to 1220 < λ < 1250 Å. (Upper right) Poisson S/N in each bin. Features are spectral lines or grid wires. (Right) Normalized S II spectrum showing how well weak lines can be identified.
The Direct Approach
To determine limiting S/N, need good error
estimates for the fixed pattern template.
1. Uncalibrated standard stars typically have simple continua,
whose line free regions can be represented by polynomials. 2. Align all spectra in wavelength space and fit them with one
polynomial.
3. Divide each spectrum by the fit and average the results in
detector space to get the fixed pattern noise. 4. No iteration needed.
5. Template errors follow from simple propagation of errors.
Some limitations:
• Only works for sources with simple continua.
Examples of polynomial fits
Examples of fits to 4 FPPOS NET spectra from program 12086.
Regions containing stellar lines (other than Ly α), IS lines and grid
wire shadows have been eliminated. These high S/N data show how well polynomials fit the NET spectra.
Comparison of iterative and direct flats. Ratios of the NET spectra
(black) and templates (red) -- both smoothed by 64 points to highlight
Portions of a 1-D flat showing ±1σ errors. Data are binned over 3 pixels,
Histograms characterizing fixed pattern noise in each grating/detector. Plots show the dispersion about the mean of the fixed pattern templates
including the grid wires (black), without grid wires (red) and expected
The Bottom Line for Standard
Processing
RMS S/N over the regions 1300 < x < 152000 for
FUVA and 1000 < x < 145000 -- corrected for
Poisson noise.
G130M
G160M
FUVA FUVB
FUVA
FUVB
RMS S/N 17.9
23.8
14.9
20.4
Max S/N 35.7
47.6
29.9
40.8
• G130M is better than G160M because it’s fatter.
• FUVB is better than FUVA because it is.
• To improve, a full 1-D flat is needed.
