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