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Changeset 41207


Ignore:
Timestamp:
Dec 18, 2019, 3:51:28 PM (7 years ago)
Author:
eugene
Message:

working on referee comments

Location:
trunk/doc/release.2015/ps1.datasystem
Files:
2 edited

Legend:

Unmodified
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  • trunk/doc/release.2015/ps1.datasystem/datasystem.tex

    r41206 r41207  
    10561056\ippprog{psphotFullForce} program.
    10571057
    1058 The convolved galaxy models are also re-measured on the
    1059 \ippstage{warp} images by the \ippstage{fullforce} stage analysis.  In
    1060 this analysis, the galaxy models determined by the
     1058\textmod{The convolved galaxy models are also re-measured by the
     1059  \ippstage{fullforce} stage analysis using the \ippstage{warp}
     1060  images.}  In this analysis, the galaxy models determined by the
    10611061\ippstage{staticsky} photometry analysis are used to seed the analysis
    1062 in the individual \ippstage{warp} images.  The purpose of this
     1062in the individual \ippstage{warp} images.
     1063
     1064The analysis tests a grid of galaxy model parameters in the vicinity
     1065of the prior from the stack.  For each warp image, each parameter set
     1066is used to generate a model which is then convolved with the PSF for
     1067that warp image and then compared to the observed data.  The resulting
     1068grid of $\chi^2$ values can then be for the
     1069
     1070For each object, a grid of galaxy model parameters is used compared tested on each
     1071warp image and
     1072
     1073** we calculate a normalization and chisq for each warp grid point.
     1074the chi square values can be summed across warps to give the solution
     1075chi square dist.  for a single warp, the error on Io goes like
     1076sqrt(Ncnts).  The average Io value is the weighted averages of the
     1077inputs.  The error on the weighted average is sqrt(1 / (sum(1/sigma^2))). 
     1078
     1079S_t^2 = 1 / (1 / S_0^2 + 1 / S_1^2 + 1 / S_2^2)
     1080
     1081S_0^2 = N0, S_1^2 = N1, etc
     1082
     1083S_t^2 = 1 / (1/N0 + 1/N1 + 1/N2 ...)
     1084
     1085ideal: S_t^2 = N0 + N1 + N2
     1086
     1087dI / Io = 1 / sqrt(No)
     1088
     1089The error on the
     1090
     1091\textmod{For each warp
     1092  image, the galaxy model (convolved with the PSF) is compared to the
     1093  observed pixels to calculate an element of the total model $\chi^2$ value
     1094
     1095 a grid
     1096of the galaxy model parameters are 
     1097
     1098how does the error scale if I fit each Io for each warp vs a single
     1099value? (sounds like I do kill the S/N...)
     1100
     1101%%%%% fix all of this...
     1102
     1103The purpose of this
    10631104analysis is the same as the \ippstage{fullforce} PSF photometry: the
    10641105PSF of the \ippstage{stack} image is poorly determined due to the
     
    10931134search for hazardous asteroids and the search for Type Ia supernovae to
    10941135measure the history of the expansion of the universe.  Both of these
    1095 projects require the discovery of faint, transient source in the
     1136projects require the discovery of faint, transient sources in the
    10961137images.  For the hazardous asteroids, and solar system studies in
    10971138general, the sources are transient because they are moving between
     
    12611302metadata tables define general features of the database.
    12621303Table~\ref{tab:DVO_schema} lists the full collection of database
    1263 tables used by DVO.
     1304tables used by DVO.  \textadd{In the current implementation, as
     1305  described in more detail below, the database tables are stored on
     1306  disk using a distributed collection of FITS files, potentially
     1307  distributed across a large number of computers in the cluster.}
    12641308
    12651309In the most basic implementation, a collection of measurements for
     
    15161560divides the sky in declination into bands 7.5\degree\ high, as defined
    15171561by the HST Guide Star Catalog
    1518 \citep[GSC][]{1988IAUS..133..239J,1990AJ.....99.2019L}.  Level 2
     1562\citep[GSC,][]{1988IAUS..133..239J,1990AJ.....99.2019L}.  Level 2
    15191563subdivides these declination bands in the RA direction, with spacing
    15201564related to the stellar density.  Level 3 divides these RA chunks into
     
    17871831exposures which were believed to be obtained in photometric
    17881832conditions.  This process, called ``\"ubercal'', is described in
    1789 detail by \cite{2012ApJ...756..158S} for the first (PV1) version.  In
     1833detail by \cite{2012ApJ...756..158S} for the first (PV1) version
     1834\note{add SDSS ref mentioned in Schlafly, also in cal paper}.  In
    17901835brief, photometric periods, with time-scales of a large fraction of a
    17911836night, are identified by a combination of automatic analysis and
  • trunk/doc/release.2015/ps1.datasystem/response.v1.txt

    r41206 r41207  
    8888affected by poor PSFs in the stack.
    8989
    90   **
     90  ** th
     91
     92
     93## Section 3.11
     94
     95transient source -> transient sources
     96
     97  ** fixed.
     98
     99## Section 4.1.3
     100
     101I was confused when first encountering the word "files" here because
     102up to this point I had been thinking of the DVO as just another MySQL
     103(or other SQL-ish) database, and I wasn't sure what kind of files were
     104being referred to. I think it'd be helpful to briefly describe the
     105overall architecture of the DVO as (mostly?) spatially sharded files
     106at the beginning of section 4, even if the details of the partitioning
     107aren't described until 4.1.3.
     108
     109Missing punctuation in parenthetical HST GSC reference?
     110
     111  ** fixed
     112
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