stardust-next mission data review
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Stardust-NExT Mission Data Review. Matthew Knight December 13, 2011. Raw NavCam Images. Purpose of the dataset: archive the raw images from NavCam during Stardust NExT (12/2010-2/2011) as well as calibration image from 2007-2011 - PowerPoint PPT PresentationTRANSCRIPT
Stardust-NExT Mission Data Review
Matthew Knight
December 13, 2011
Raw NavCam Images
• Purpose of the dataset: archive the raw images from NavCam during Stardust NExT (12/2010-2/2011) as well as calibration image from 2007-2011
• Additional data: catalog files, documentation on the calibration process/shutter behavior/flat field response/etc.
Overview of review
• Documentation is very thorough and well written– Explanations are sufficient – Supplemental information supplied is relevant
• Data are clearly laid out and easy to understand what is there
• Only needs minor fixes:– A small number of typos– A handful of science suggestions
Acronyms
• A number of acronyms were used at various times in many different files either without a definition or so long after the definition was given that I had forgotten what it meant. It would be useful to have a central repository with acronym definitions, perhaps in aareadme.txt or another file at that level.
• This goes for all three data sets I reviewed• Example: I didn't figure out that EDR stands for
"Edited, raw data record" until I saw it in stardust-cal-nc-2-preflight-v2.0/document/onlabels.txt
This also allows me to infer that RDR must stand for "raw data record"
Catalog/navcam.cat• What does “blocking”
mean?• Are the blocking
values in Ang rather than nm?
• NH2: should I interpret this as “less than 10^-2 for wavelengths less than 6500 and longer than 6800; less than 10^-3 for wavelengths shorter than 6450 and longer than 6850?”
Catalog/navcam.cat• Same interpretation for
Oxygen?• For C2
– Does this mean “less than 10^-1 from 3000 to 5051 and 5230 to 11000”?
– Same notation should be used throughout (“,” here but “-” later)
– At what wavelengths are these transmissions valid?
Catalog/navcam.cat• Similar questions for
YELLOW, RED, NIR• Should HIRES be 3000-
4800 (not 3000-480?) • Note the “nanometers”
statement at the bottom• Are these transmission
curves given somewhere else (if so, please mention where)?– Plots: sdu-c_cal-navcam-2-
next-tempel1-v1.0/document/olddoc/calibrpt.pdf
– Ascii: stardust-cal-nc-2-preflight-v2.0/document/stardust/calrpt
Catalog/navcam.cat
• Is the new look-up table archived here? Where?
Catalog/next.cat
• What happened to 2011-2-14, 2011-2-16?– Should all of the mission phases be
consecutive or is it okay to have gaps?
Catalog/dataset.cat
• “Data collection periods” section has write ups of “Checkout, Cruise 5, and Cruise 6” and “Encounter”, but not “Approach” or “Departure”. Is this intentional?
Document/nc_cal_overview.*
• Why is the calibration procedure called “decalibration” instead of “calibration”?– Klaasen et al. (2011) call it “calibration”
How might I use the data?
• Make a flyby movie (raw data)
• Very easy to do with all images in ds9
QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
How might I use the data?
• Measure a lightcurve of the comet– Problem: I’m not sure where the comet is
except very close to flyby.– Suggestion: Make a table with the position
of the comet in each image• X,Y position or RA,dec is okay with me
• Lightcurve will be shown in Calibrated section
Calibrated NavCam Images
• The same as raw NavCam images, except these have been calibrated
• Documentation is virtually identical– All comments were given in Raw NavCam
presentation
Calibrated NavCam Images
• Why doesn’t the calibration get rid of the striping?
How might I use the data?• Make a lightcurve
of the comet on approach
• Method: find comet, measure photometry from images, extract distance to spacecraft and date from header
• Result: rotation visible, change in spatial scale evident
NavCam Ground-based Calibration Data
• Contains the raw, preflight, thermal-vacuum calibration images– Testing at various temperatures, exposure
times, radiances
• Review summary:– Documentation is very thorough and well
written– Minimal typos; no problems using the
images for science– Easy to understand what was there
How might I use the data?
• Measure the flux as a function of T– Read in fits files– Took the
median of the whole image to get the flux
– Got temperature, radiance, exposure time from the headers
How might I use the data?
• Measure the flux as a function of T– Result:
corrected for radiance to get a better correlation