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III. NEOWISE Single-exposure Images

III.1. General Properties


III.1.c. Single-exposure (Level 1) Image Metadata Column Descriptions

This table contains brief descriptions of all metadata information that is relevant to the processing of Single-exposure (Level 1) images and the extraction of sources from the corresponding Single-exposure images. The table contains the unique scan ID and frame number for specific each single-exposure image and the reconstructed right ascension and declination of the image center. Much of the information in this table is processing-specific, and may not be of interest to general users (e.g. flags indicating whether frames have been processed or not, and the date and time for starting of the pipeline, etc). The metadata table also contains some characterization and derived statistics of the Single-exposure image frames, basic parameters used for photometry and derived statistics for extracted sources and artifacts. For example, it contains the number of sources with profile-fit photometry Signal-to-Noise (SNR) greater than 3, and the total number of real sources affected by artifacts such as latent images and electronic ghosts.

The columns in the following table are:


N.B. - The true observation mid-point times for NEOWISE images are slightly earlier than the time reported in this column (see I.2.c.iii.1). For images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the report time. For images acquired after that date, the observation times are approximately 0.57±0.25 sec earlier than the reported value.


Column NameFormatUnitsnullsDescription 
scan_id %6s ---- no Scan identifier. This is a six-character string that identifies a block of survey exposures that are acquired between two flight system maneuvers, such as reorientation of the instrument boresight near the ecliptic poles, or slews to acquire TDRSS for data downlink contacts. Because maneuvers often take place near the ecliptic poles, the scan number is roughly associated with a half-orbit's worth of images. However, scans can cover less or more than half of the arc between ecliptic poles.

The scan_id has the general form SSSSSx, where

  • SSSSS is a zero-filled, five-digit integer that is related to the NEOWISE orbit number. The orbit number increments each time the flight system passes the north ecliptic pole (NEP). Orbit number 1 was defined to start with the fictitious NEP passage immediately prior to the WISE launch. Up through scan number 99799, SSSSS is twice the orbit number. Following scan number 99799, SSSSS rolls over to 01000, and is twice the orbit number, minus 98800. Scan numbers following the rollover are also distinguished by having different values of x.

  • x   is a letter assigned based on the sequential count of scans started in a specific half-orbit. For scans up to and including 99799, x="a" unless there is a second scan in the same half-orbit, in which case x="b". For scans after 99799, x="r" unless there is a second scan in the same half-orbit, in which case x="s".

The first scan whose data are used in the NEOWISE Data Release is scan 44212a. This was the first scan after the NEP crossing in the 22,106th WISE/NEOWISE orbit. The final scan included in the Release is 57041r, the first scan after the SEP crossing in the 77,920th orbit.

 
frame_num %3d ---- no Number of the frameset on which this source was extracted. The identifier has the general form MMM, a zero-filled three-digit number.

The frameset number is computed based on time bins which count from the scan start time:

fr_num = int[((frame_utc - dt_beg) - scan_start_utc)/bin_size] + 1

where

  • int[] means truncate to an integer
  • frame_utc is the nominal frame exposure center UTC (when the boresight crosses the image center) in seconds
  • dt_beg is 4.4s. This is a nominal offset to approximate when the exposure began
  • scan_start_utc is the scan start time in seconds
  • bin_size is 10s.

For example, a frame with a start time 1234 secs after the scan start time would have a frame number of 124.

N.B.

  • Frame_num is not a frameset sequence number

  • As a result of using a 10 sec bin, every 11th frame skips a number, so it is normal to see breaks in the frame numbering and it doesn't indicate missing data.

  • Because frameset numbering is based on the predicted scan start time from the survey plan, and because frameset data may not start being acquired until well after the start of the scan, frameset numbers often do not start at 001 for a scan.
 
date_proc %20s datetimeZ no The date and time of the start of WISE pipeline processing in Coordinated Universal Time (UTC). For example, scan 44212a, frameset number 124 was processed starting at 2014-05-29 21:22:04.  
elapsed_t %7.2f second no The elapsed processing time from the start of the WISE pipeline processing, in units of seconds. This is wall clock time.  
ucpu_t %7.2fsecno User CPU time for pipeline processing, in seconds.  
scpu_t %7.2fsecno System CPU time for pipeline processing, in seconds.  
status %2d---- no This integer describes how the multi-frame pipeline terminated. A status of 0 means that the processing was successfully executed; any other status value means it failed. All status values in the metadata will be 0.  
ra0 %10.6f deg no Right ascension (J2000) of the raw image frame (level 0) center.  
dec0 %10.2f deg no Declination (J2000) of the raw image frame (level 0) center.  
crota0 %17.12f deg no Image twist of the raw image (level 0): the position of the image y-axis West of North at the EQUINOX; in the opposite direction of the conventional Position Angle, where position angle (P.A.) = -CROTA0.  
rssrate %17.14f arcmin/s no The root square sum of the three telescope axes spacecraft scan rates.  
moon_sep %7.3f deg yes The angular distance from the frame center to the Moon.  
saa_sep %7.3f deg yes SAA separation. This column contains the angular separation on the sky, in degrees, between the apparent position of NEOWISE and the boundary of the South Atlantic Anomaly (SAA) at the time of observation for the frameset on which this entry was extracted. Positive values indicate that NEOWISE was outside of the SAA boundary. Negative values indicate that NEOWISE was within the SAA boundary.

CAUTION: Single-exposure source database entries having negative or small positive (< 5.0) values of saa_sep should be used with caution. The large flux of charged particles within the SAA produces a very high incidence of radiation hits that can contaminate measurements of real sources or lead to many spurious Single-exposure source extractions. Looking at the Single-exposure images taken of the same position when NEOWISE was not within the SAA is a good way to assess source reliability.

 
ra %10.6f deg no The right ascension (J2000) of the position-reconstructed Single-exposure frame (level 1b) center with respect to the 2MASS PSC reference frame.  
dec %10.6f deg no The declination (J2000) of the position-reconstructed Single-exposure frame (level 1b) center with respect to the 2MASS PSC reference frame.  
crota %17.12f deg no Image twist of the position-reconstructed, Single-exposure frame (level 1b): the position of the image y-axis West of North at the EQUINOX; in the opposite direction of the conventional Position Angle, where position angle (P.A.) = -CROTA.  
bandbits %2d ---- no Bit-wise flag that indicates which bands have been processed, starting at band 1 and bit 0.  
w1bandrun %1d ---- no This flag indicates whether band 1 has been processed; 1 means yes and 0 means no.  
w2bandrun %1d ---- no This flag indicates whether band 2 has been processed; 1 means yes and 0 means no.  
date_obs %24s datetimeZ no The date and time of the mid-point of the frameset exposure, in UTC. The mid-point is defined as the time the optical boresight crosses the center of the WISE focal planes. This time is the same for all bands, whereas the exposure times in W1 and W2 are different than in W3 and W4.

N.B. - The true observation mid-point times for NEOWISE images are slightly earlier than time reported in this column (see I.2.c.iii.1). For images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the report time. For images acquired after that date, the observation times are approximately 0.57±0.25 sec earlier than the reported value.

 
mjd %12.6f day yes The Modified Julian Date of the mid-point of the frameset exposure. The mid-point is defined as the time the optical boresight crosses the center of the WISE focal planes. This time is the same for all bands.

N.B. - The true observation mid-point times for NEOWISE images are slightly earlier than time reported in this column (see I.2.c.iii.1). For images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the report time. For images acquired after that date, the observation times are approximately 0.57±0.25 sec earlier than the reported value.

 
wsds_vsn %20s ---- no The version number of the NEOWISE pipeline used for this current data release.  
date_dbprep %20s datetimeZ no The date and time when the data was prepared by the NEOWISE archive software DBPREP for the archive loading, in UTC.  
draf %10.3f arcsec yes The true-angular difference in RA between the band-frame centers before and after position reconstruction, for the lowest band processed.  
ddecf %10.3f arcsec yes The angular difference in declination between the band-frame centers before and after position reconstruction, for the lowest band processed.  
dpaf %12.3f arcsec yes The difference in the frame position angle before and after position reconstruction, for the lowest band processed.  
sigraf %11.6f arcsec yes The final band-frame sigma on RA for the lowest band processed.  
sigdcf %11.6f arcsec yes The final band-frame sigma on declination for the lowest band processed.  
sigpaf %9.3f arcsec yes The final band-frame sigma on PA for lowest band processed.  
qflgsf %14s ---- no The single-frame positional reconstruction quality flag.  
band_prex %1d ---- no The lowest band processed by the Single-frame positional reconstruction pipeline (SFPREX). This band is used for calculating draf, ddecf, dpaf, sigraf, sigdcf, and sigpaf.  
dra_frame %10.3f arcsec yes The right ascension difference (RA) between level 0 and refined level 1 frame center.  
ddec_frame %10.3f arcsec yes The declination difference (DEC) between level 0 and the refined level 1 frame center.  
dpa_frame %11.3f arcsec yes The position angle difference between level 0 and the refined level 1 frame center.  
moon_masked %4s ---- yes Moon masking flag. This is a two-character flag, one character per band, that indicates if the single-exposure database frameset from which this entry was extracted falls within the area covered by the prior moon masks. A value of '0' in a band indicates that the frameset is not in the mask area, and a value of '1' indicates that the frameset is in the mask area. These fixed area masks denote regions contaminated by scattered light from the moon, and are different for each band.

CAUTION: Single-exposure source database entries having a moon_masked value of '1' in either band should be used with caution. Framesets in the moon mask areas may have large scale image artifacts that induce spurious detections or contaminate real source measurements. To select detections from framesets that have the best chance of being free from contamination by scattered moonlight in both bands, select detections where moon_masked='00'.

 
w1msknumtotbad %7d---- yes The number of pixels in the single-exposure frame that were tagged in the frame mask with a non-zero value for band 1. Not all conditions under which pixels were tagged are fatal.  
w2msknumtotbad %7d---- yes The number of pixels in the single-exposure frame that were tagged in the frame mask with a non-zero value for band 2. Not all conditions under which pixels were tagged are fatal.  
w1msknumdynabad %7d---- no The number of dynamically masked pixels in ical processing, band 1.  
w2msknumdynabad %7d---- no The number of dynamically masked pixels in ical processing, band 2.  
w1msknumsat %7d ---- yes The number of pixels in the single-exposure frame that saturated at any sample-up-the ramp read for band 1.  
w2msknumsat %7d ---- yes The number of pixels in the single-exposure frame that saturated at any sample-up-the-ramp read for band 2.  
w1intnspikelo %7d ---- yes The number of low valued "pixel-spike" outliers falling in the low-tail of the frame-pixel distribution for band 1. These are defined as spatial outliers, i.e., with respect to other neighboring pixels.  
w2intnspikelo %7d ---- yes The number of low valued "pixel-spike" outliers falling in the low-tail of the frame-pixel distribution for band 2. These are defined as spatial outliers, i.e., with respect to other neighboring pixels.  
w1intnspikehi %7d ---- yes The number of high valued "pixel-spike" outliers falling in the high-tail of the frame-pixel distribution for band 1. These are defined as spatial outliers, i.e., with respect to other neighboring pixels.  
w2intnspikehi %7d ---- no The number of high valued "pixel-spike" outliers falling in the high-tail of the frame-pixel distribution for band 2. These are defined as spatial outliers, i.e., with respect to other neighboring pixels.  
w1skynumlo %7d ---- yes The number of pixels whose values are very low, < -20DN, in the skyoffset calibration product for band 1.  
w1skynumhi %7d ---- yes The number of pixels whose values are very high, > 20DN, in the skyoffset calibration product for band 1.  
w2skynumlo %7d ---- yes The number of pixels whose values are very low, less than -20DN, in the skyoffset calibration product for band 2.  
w2skynumhi %7d ---- yes The number of pixels whose values are very high, greater than 20DN, in the skyoffset calibration product for band 2.  
w1intmean %15.6fDN yes The mean pixel value in the intensity image of the single-exposure frame for band 1.  
w2intmean %15.6fDN yes The mean pixel value in the intensity image of the single-exposure frame for band 2.  
w1intmedian %15.6fDN yes The median pixel value in the intensity image of the single-exposure frame for band 1.  
w2intmedian %15.6fDN yes The median pixel value in the intensity image of the single-exposure frame for band 2.  
w1intstddev %15.6fDN yes The standard deviation (RMS) from the mean (unbiased population estimate), band 1.  
w2intstddev %15.6fDN yes The standard deviation (RMS) from the mean (unbiased population estimate), band 2.  
w1intsigltmadmed %15.6fDN yes The lower-tail median absolute deviation from the median (a robust estimate of sigma) for pixels in the intensity image of the single-exposure frame for band 1.  
w2intsigltmadmed %15.6fDN yes The lower-tail median absolute deviation from the median (a robust estimate of sigma) for pixels in the intensity image of the single-exposure frame for band 2.  
w1inti16_84range %15.6fDN yes An estimate of sigma using the difference of the 84th - 16th percentile values for pixels in the intensity image of the single-exposure frame for band 1. It will be biased high if a high source density is present.  
w2inti16_84range %15.6fDN yes An estimate of sigma using the difference of the 84th - 16th percentile values for pixels in the intensity image of the single-exposure frame for band 2. It will be biased high if a high source density is present.  
w1intmed16ptile %15.6fDN yes A robust estimate of sigma using the difference of the 50th - 16th percentile values for pixels in the intensity image of the single-exposure frame for band 1.  
w2intmed16ptile %15.6fDN yes A robust estimate of sigma using the difference of the 50th - 16th percentile values for pixels in the intensity image of the single-exposure frame for band 2.  
w1intratmedrange %15.6f---- yes The ratio of the (84th percentile - mode) / (mode - 16th percentile) for pixels in the intensity image of the single-exposure frame for band 1.  
w2intratmedrange %15.6f---- yes The ratio of the (84th percentile - mode) / (mode - 16th percentile) for pixels in the intensity image of the single-exposure frame for band 2.  
w1unclocscal2 %15.6f---- yes The ratio of the local RMS in intensity pixel fluctuations using the lower-tail deviation from the mode to the modal pixel uncertainty from the model, for band 1. It is analogous to the pseudo-χ2 measures defined above, but is even more robust against the presence of sources and bright, extended structure.  
w2unclocscal2 %15.6f---- yes The ratio of the local RMS in intensity pixel fluctuations using the lower-tail deviation from the mode to the modal pixel uncertainty from the model, for band 2. It is analogous to the pseudo-χ2 measures defined above, but is even more robust against the presence of sources and bright, extended structure.  
naxis %2d ---- yes The number of image data axes.  
w1naxis1 %4d ---- yes The number of image pixels in x (axis 1), band 1.  
w1naxis2 %4d ---- yes The number of image pixels in y (axis 2), band 1.  
w2naxis1 %4d ---- yes The number of image pixels in x (axis 1), band 2.  
w2naxis2 %4d ---- yes The number of image pixels in y (axis 2), band 2.  
w1crpix1 %6.1f ---- yes The image reference pixel value at the single frame image center for axis 1 (x), band 1.  
w1crpix2 %6.1f ---- yes The image reference pixel value for axis 2 (y), band 1.  
w2crpix1 %6.1f ---- yes The image reference pixel value for axis 1 (x), band 2.  
w2crpix2 %6.1f ---- yes The image reference pixel value for axis 2 (y), band 2.  
w1crval1 %16.12f deg yes The reference RA (J2000) position at the image center (crpix1, crpix2), band 1.  
w1crval2 %16.12f deg yes The reference DEC (J2000) position at the image center (crpix1,crpix2), band 1.  
w1crder1 %20.14e deg yes The uncertainty value in crval1 (RA), band 1.  
w1crder2 %20.14e deg yes The uncertainty value in crval2 (DEC), band 1.  
w1csdradec %21.14e deg yes The co-standard deviation (RMS) in crval1 and crval2 (RA and DEC), band 1.  
w2crval1 %16.12f deg yes The reference RA (J2000) position at the image center (crpix1, crpix2), band 2.  
w2crval2 %16.12f deg yes The reference DEC (J2000) position at the image center (crpix1,crpix2), band 2.  
w2crder1 %20.14e deg yes The uncertainty value in crval1 (RA) for band 2.  
w1crder2 %20.14e deg yes The uncertainty value in crval2 (DEC) for band 2.  
w2sdradec %21.14e deg yes The co-standard deviation (RMS) in crval1 and crval2 (RA and DEC), band 2.  
ctype1 %13s -- yes The image projection type (including distortion) for axis 1 (x, same for all bands).  
ctype2 %13s -- yes The image projection type (including distortion) for axis 2 (y, same for all bands).  
equinox %6.1f year yes The equinox of the World Coordinate System in the image header (same for all bands).  
w1elon %16.12f deg yes Ecliptic longitude at the center of the image for band 1.  
w1elat %16.12f deg yes Ecliptic latitude at the center of the image for band 1.  
w1glon %16.12f deg yes Galactic longitude at the center of the image for band 1.  
w1glat %16.12f deg yes Galactic latitude at the center of the image for band 1.  
w2elon %16.12f deg yes Ecliptic longitude at the center of the image for band 2.  
w2elat %16.12f deg yes Ecliptic latitude at the center of the image for band 2.  
w2glon %16.12f deg yes Galactic longitude at the center of the image for band 2.  
w2glat %16.12f deg yes Galactic latitude at the center of the image for band 2.  
w1ra1 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 1 at (crpix1,crpix2=-0.5,-0.5) for band 1.  
w1dec1 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 1 at (crpix1,crpix2=-0.5,-0.5) for band 1.  
w1ra2 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 2 at (crpix1,crpix2=naxis1+0.5,-0.5) for band 1.  
w1dec2 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 2 at (crpix1,crpix2=naxis1+0.5,-0.5) for band 1.  
w1ra3 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 3 at (crpix1,crpix2=naxis1+0.5,naxis1+0.5) for band 1.  
w1dec3 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 3 at (crpix1,crpix2=naxis1+0.5,naxis1+0.5) for band 1.  
w1ra4 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 4 at (crpix1,crpix2=-0.5,naxis1+0.5) for band 1.  
w1dec4 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 4 at (crpix1,crpix2=-0.5,naxis1+0.5) for band 1.  
w2ra1 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 1 at (crpix1,crpix2=-0.5,-0.5) for band 2.  
w2dec1 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 1 at (crpix1,crpix2=-0.5,-0.5) for band 2.  
w2ra2 %16.12f deg yes The Right Ascension (RA, J2000) of the image corner No. 2 at (crpix1,crpix2=naxis1+0.5,-0.5) for band 2.  
w2dec2 %16.12f deg yes The Declination (DEC, J2000) of the image corner No. 2 at (crpix1,crpix2=naxis1+0.5,-0.5) for band 2.  
w2ra3 %16.12f deg no The Right Ascension (RA, J2000) of the image corner No. 3 at (crpix1,crpix2=naxis1+0.5,naxis1+0.5) for band 2.  
w2dec3 %16.12f deg no The Declination (DEC, J2000) of the image corner No. 3 at (crpix1,crpix2=naxis1+0.5,naxis1+0.5) for band 2.  
w2ra4 %16.12f deg no The Right Ascension (RA, J2000) of the image corner No. 4 at (crpix1,crpix2=-0.5,naxis1+0.5) for band 2.  
w2dec4 %16.12f deg no The Declination (DEC, J2000) of the image corner No. 4 at (crpix1,crpix2=-0.5,naxis1+0.5) for band 2.  
w1wcdelt1 %21.18f deg/pix no The image scale in deg/pixel at the reference position of (crpix1,crpixe) for axis 1 (x), band 1.  
w1wcdelt2 %21.18f deg/pix no The image scale in deg/pixel at the reference position of (crpix1,crpixe) for axis 2 (y), band 1.  
w1uncrts1 %20.14e deg no The uncertainty value in the image scale, wcdelt1, for band 1.  
w1uncrts2 %20.14e deg no The uncertainty value in the image scale, wcdelt2, for band 1.  
w1pxscal1 %17.14f arsec/pix no The image scale in Arcsecond/pixel at the reference position of the image (crpix1,crpix2) for axis 1 (x) for band 1.  
w1pxscal2 %17.14f arsec/pix no Arcsecond/pixel scale at the reference position of the image (crpix1,crpix2) for axis 2 (y), for band 1.  
w2wcdelt1 %21.18f deg/pix no The image scale in deg/pixel at the reference position of (crpix1,crpixe) for axis 1 (x), band 2.  
w2wcdelt2 %21.18f deg no The image scale in deg/pixel at the reference position of (crpix1,crpixe) for axis 2 (y), band 2.  
w2uncrts1 %20.14e deg/pix no The uncertainty value in the image scale, wcdelt1, for band 2.  
w2uncrts2 %20.14e deg no The uncertainty value in the image scale, wcdelt2, for band 2.  
w2pxscal1 %17.14f arsec/pix no The image scale in arcsecond/pixel at the reference position of the image (crpix1,crpix2) for axis 1 (x) for band 2.  
w2pxscal2 %17.14f arsec/pix no The image scale in arcsecond/pixel at the reference position of the image (crpix1,crpix2) for axis 2 (y) for band 2.  
w1pa %18.3f deg no The image position angle relative to Axis 2 (y) E of N, band 1.  
w1uncrtpa %21.18f deg no The uncertainty in the image position angle, band 1.  
w2pa %18.3f deg no The image position angle relative to Axis 2 (y) E of N, band 2.  
w2uncrtpa %21.18f deg no The uncertainty in the image position angle, band 2.  
w1skew %5.1f --- no The measure of non-orthogonality of image frame axes, band 1.  
w2skew %5.1f --- no The measure of non-orthogonality of image frame axes, band 2.  
w1cd1_1 %21.18f deg/pix no The image CD matrix element (1,1), for band 1.  
w1cd1_2 %21.18f deg/pix no The image CD matrix element (1,2), for band 1.  
w1cd2_1 %21.18f deg/pix no The image CD matrix element (2,1), for band 1.  
w1cd2_2 %21.18f deg/pix no The image CD matrix element (2,2), for band 1.  
w2cd1_1 %21.18f deg/pix no The image CD matrix element (1,1), for band 2.  
w2cd1_2 %21.18f deg/pix no The image CD matrix element (1,2), for band 1.  
w2cd2_1 %21.18f deg/pix no The image CD matrix element (2,1), for band 2.  
w2cd2_2 %21.18f deg/pix no The image CD matrix element (2,2), for band 2.  
bunit %20s --- no The image data unit.  
w1modeint %10.3f DN no The mode of image pixel values within the lowest sigma partition, band 1.  
w2modeint %10.3f DN no The mode of image pixel values within the lowest sigma partition, band 2.  
w1magzpunc %9.6f mag no 1-sigma uncertainty in the photometric zero-point magnitude for band 1.  
w2magzpunc %9.6f mag no 1-sigma uncertainty in the photometric zero-point magnitude for band 2.  
unixt %16.5f sec no UNIX date-time in seconds of the mid-point of the frame observation, UTC (same for all bands).

N.B. - The true observation mid-point times for NEOWISE images are slightly earlier than time reported in this column (see I.2.c.iii.1). For images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the report time. For images acquired after that date, the observation times are approximately 0.57±0.25 sec earlier than the reported value.

 
ephemt %16.6f sec no Ephemeris date-time in seconds of the mid-point of the frame observation, UTC (same for all bands).

N.B. - The true observation mid-point times for NEOWISE images are slightly earlier than time reported in this column (see I.2.c.iii.1). For images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the report time. For images acquired after that date, the observation times are approximately 0.57±0.25 sec earlier than the reported value.

 
w1exptime %4.1f sec no The frame exposure time, band 1.  
w2exptime %4.1f sec no The frame exposure time, band 2.  
tsamp %4.1f sec no The time interval between non-destructive reads of the samples along the ramp.  
w1l0file %200s --- no Corresponding level 0 image file name, band 1.  
w2l0file %200s --- no Corresponding level 0 image file name, band 2.  
icaldir %200s icaldir no The reference file directory used by the data processing module ICAL.  
dtanneal %18.11f sec no The time since last anneal.  
utanneal %24s datetimeZ no The date and time of last anneal, UTC.  
w1npn %2d ---- no The number of different Point-Spread-Functions used in a grid over each image frame in band 1. These PSFs take into account the differences in distortion across the frames.  
w2npn %2d ---- no The number of different Point-Spread-Functions used in a grid over each image frame in band 2. These PSFs take into account the differences in distortion across the frames.  
nsrcall %7d---- no The number of sources from the source detection subsystem loaded into the photometry subsystem for the frameset.  
w1zero %7.3fmag no The photometric zero point magnitude for the Single-exposure image for band 1.  
w2zero %7.3fmag no The photometric zero point magnitude for the Single-exposure image for band 2.  
w1rap_1 %6.3f arcsec yes The radius of circular aperture 1, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_1 %6.3f arcsec yes The radius of circular aperture 1, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_2 %6.3f arcsec yes The radius of circular aperture 2, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_2 %6.3f arcsec yes The radius of circular aperture 2, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_3 %6.3f arcsec yes The radius of circular aperture 3, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_3 %6.3f arcsec yes The radius of circular aperture 3, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_4 %6.3f arcsec yes The radius of circular aperture 4, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_4 %6.3f arcsec yes The radius of circular aperture 4, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_5 %6.3f arcsec yes The radius of circular aperture 5, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_5 %6.3f arcsec yes The radius of circular aperture 5, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_6 %6.3f arcsec yes The radius of circular aperture 6, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_6 %6.3f arcsec yes The radius of circular aperture 6, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_7 %6.3f arcsec yes The radius of circular aperture 7, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_7 %6.3f arcsec yes The radius of circular aperture 7, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1rap_8 %6.3f arcsec yes The radius of circular aperture 8, in arcseconds, used for aperture photometry in band 1. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w2rap_8 %6.3f arcsec yes The radius of circular aperture 8, in arcseconds, used for aperture photometry in band 2. The WISE aperture photometry was performed with a set of 8 fixed circular apertures, with radii of 5.5, 8.25, 11.0, 13.75, 16.5, 19.25, 22.0, and 24.75 arcseconds in bands 1, 2, and 3.  
w1stap %6.3f arcsec no The radius in arcseconds of the standard circular aperture used for aperture photometry in band 1, nominally 8.25 arcseconds.  
w2stap %6.3f arcsec no The radius in arcseconds of the standard circular aperture used for aperture photometry in band 2, nominally 8.25 arcseconds.  
ntable %7d---- no The total number of sources extracted in the photometry subsystem in the Single-exposure image frameset.  
nwpro_adb %7d---- no The number of sources in the frameset that were actively deblended before performing profile-fit photometry.  
npro_nbad %7d ---- no The number of sources in the frameset whose profile fitting photometry failed with an uncertainty value less than 0.0.  
w1n3sig %7d ---- no The number of sources in the frameset whose profile-fit photometry have SNR > 3 for band 1.  
w2n3sig %7d ---- no The number of sources in the frameset whose profile-fit photometry have SNR > 3 for band 2.  
w1n3sig_only %7d ---- no The number of sources in the frameset whose profile-fit photometry have SNR > 3 in band 1 only.  
w2n3sig_only %7d ---- no The number of sources in the frameset whose profile-fit photometry have SNR > 3 in band 2 only.  
n12 %7d ---- no The number of sources in the frameset whose profile-fit photometry have SNR > 3 in bands 1 and 2.  
nrchi_0_05 %7d ---- no The number of sources in the frameset whose profile-fit photometry have rchi2 values between 0 and 0.5.  
nrchi_05_2 %7d ---- no The number of sources in the frameset whose profile-fit photometry have rchi2 values between 0.5 and 2.  
nrchi_2_5 %7d ---- no The number of sources in the frameset whose profile-fit photometry have rchi2 values between 2 and 5.  
nrchi_5_15 %7d ---- no The number of sources in the frameset whose profile-fit photometry have rchi2 values between 5 and 15.  
nrchi_15 %7d ---- no The number of sources in the frameset whose profile-fit photometry have rchi2 values greater than 15.  
nblend_1 %7d ---- no The number of sources in the frameset that were not deblended before performing profile-fit photometry.  
nblend_2 %7d ---- no The number of sources in the frameset that were actively deblended into 2 individual sources.  
nblend_3 %7d ---- no The number of sources in the frameset that were actively deblended into 3 individual sources.  
nblend_4 %7d ---- no The number of sources in the frameset that were actively deblended into 4 individual sources.  
nblend_5 %7d ---- no The number of sources in the frameset that were actively deblended into 5 or more individual sources.  
w1n_rdiff %6d ---- no The number of real sources flagged as contaminated by diffraction spikes in band 1.  
w2n_rdiff %6d ---- no The number of real sources flagged as contaminated by diffraction spikes in band 2.  
w1n_rlshort %6d ---- no The number of real sources flagged as contaminated by short-term latents in band 1.  
w2n_rlshort %6d ---- no The number of real sources flagged as contaminated by short-term latents in band 2.  
w1n_rhalo %6d ---- no The number of real sources flagged as contaminated by halos in band 1.  
w2n_rhalo %6d ---- no The number of real sources flagged as contaminated by halos in band 2.  
w1n_roghost %6d ---- no The number of real sources flagged as contaminated by optical ghosts in band 1.  
w2n_roghost %6d ---- no The number of real sources flagged as contaminated by optical ghosts in band 2.  
w1n_rglint %6d ---- no The number of real sources flagged as contaminated by glints in band 1.  
w2n_rglint %6d ---- no The number of real sources flagged as contaminated by glints in band 2.  
w1n_sdiff %6d ---- no The number of sources flagged as spurious detections of diffraction spikes in band 1.  
w2n_sdiff %6d ---- no The number of sources flagged as spurious detections of diffraction spikes in band 2.  
w1n_slshort %6d ---- no The number of spurious sources affected by short-term latents in band 1.  
w2n_slshort %6d ---- no The number of spurious sources affected by short-term latents in band 2.  
w1n_shalo %6d ---- no The number of spurious sources caused by halos in band 1.  
w2n_shalo %6d ---- no The number of spurious sources caused by halos in band 2.  
w1n_soghost %6d ---- no The number of spurious sources that are affected by optical ghosts in band 1.  
w2n_soghost %6d ---- no The number of spurious sources that are affected by optical ghosts in band 2.  
w1n_rtot %6d ---- no The total number of real sources flagged as contaminated by artifacts in band 1.  
w2n_rtot %6d ---- no The total number of real sources flagged as contaminated by artifacts in band 2.  
n_rtot %6d ---- no The total number of real sources flagged as contaminated by artifacts in all four bands.  
w1n_stot %6d ---- no The total number of spurious sources affected by artifacts in band 1.  
w2n_stot %6d ---- no The total number of spurious sources affected by artifacts in band 2.  
n_stot %6d ---- no The total number of spurious sources affected by artifacts in all four bands.  
r_major %7d ---- no The major axis that is the 2nd moment of the rotated-axis.  
rbovera %6.4f ---- no The axial ratio of the calculated frame PSF for the lowest band available.  
r_phi %7d ---- no The position angle (EofN) from the rotated-axis 2nd moment.  
r_05p %7d ---- no The semi-major axis of the half-power points.  
r_01p %7d ---- no The semi-major axis of the 0.1-power points.  
bovera %7d ---- no The axis ratio calculated at the 0.1-power points.  
noisepix %9.3f pix no The effective number of noise pixels in the frame PSF for the lowest band available.  
r_mean_20_allwise %6.3f arcsec no The mean radial separation across the full frame for the NEOWISE-ALLWISE associations with W1 SNR > 20.  
r_mean_20_2mass %6.3f arcsec no The mean radial separation across the full frame for the NEOWISE-2MASS associations with W1 SNR > 20.  
qual_frame %2d ---- yes Frame quality score. This integer indicates the quality score value for the Single-exposure image frameset, with values of 0 (poor quality), 5, or 10 (high quality). The value is determined by the minimum of the quality factors qc_fact, qn_fact, and qi_fact, multiplied by ten.

CAUTION: Single-exposure source database entries having qual_frame=0 should be used with extreme caution. They may be spurious detections of noise, transient events or scattered light, or if real, their position and/or flux measurements may be contaminated.

 
bsplmout %6.3f deg no Beam splitter mount temperature in Kelvin.  
telintft %6.3f deg no Telescope interface flange temperature in Kelvin.  
qc_fact %3.1f ---- no This quality factor gauges the quality of completion of the Single-exposure image frameset. If the status value from the processing pipeline was equal to 0 (indicating a problem-free completion), then qc=1.0. Otherwise, qc=0.0 because the frameset failed to complete processing. All framesets in the Database have received qc values of 1.0.  
qi_fact %3.1f ---- no This quality factor gauges the image shape quality of the Single-exposure image frameset. It checks for potential image smearing by using the axial ratio of the PSF calculated from a subset of sources in the frameset. The value of qi is 1.0 if the axial ratio b/a > 0.60; otherwise it is 0.0.  
qn_fact %3.1f ---- no This quality factor indicates the background and noise characteristics quality of the Single-exposure frameset.  
qual_scan %2d ---- no This integer indicates the quality score value for the scan containing the Single-exposure image frameset, with values of 0 (poor quality), 5, or 10 (high quality). The value is determined by the minimum of the quality factors qs1_fact, qs5_fact, and qp_fact, multiplied by ten.  
qs1_fact %3.1f ---- no This quality factor indicates the quality of scan synchronization as judged from the overall 1x1 PSF grid computed by the PSF Moments routine and evaluated based on the effective number of noise pixels.  
qs5_fact %3.1f ---- no This quality factor indicates the quality of scan synchronization as judged from the overall 5x5 PSF grid computed by the PSF Moments routine and evaluated based on the effective number of noise pixels.  
qp_fact %3.1f ---- yes This quality factor indicates the scan photometric quality. If the scan's photometric zero-point offset computed using profile-fit photometry (pzp) falls within a certain range about 0, the value of qp_fact is 1.0; otherwise it is 0.0.  
cntr %10d ---- no Unique identification number for the Database source. This number is formed entirely from the source_id, which is in turn formed from the scan_id, frame_num and source number, src. On average sources with cntr values close to each other are also close to each other on the sky, except at image boundaries. Cntr ordering thus provides a useful mapping of the NEOWISE release on storage media. The cntr value is formed by making the source_id into an integer, in the format: SSSSSssMMMIIIIII, where
  • SSSSSss = Scan identifier scan_id, with the letter in the last position translated into two zero-filled digits corresponding to the letter's place in the alphabet.

  • MMM = Frame number frame_num, which is three zero-filled digits.

  • IIIIII = six-digit, zero-filled, sequential extracted source number, src, within the frameset.

For example, a source in scan 44212a, frame number 057, with a source_id of 44212a057-000100, would have a cntr value of 4421201057000100.

 
x %19.16f ---- no Unit sphere position x value  
y %19.16f ---- no Unit sphere position y value  
z %19.16f ---- no Unit sphere position z value  
spt_ind %9d ---- no Level 7 HTM spatial index key  
htm20 %19ld ---- no Level 20 HTM spatial index key  


Last Update: 18 March 2024


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