Next: 1 Preface Up: ISOPHOT Data Users Manual Previous: ISOPHOT Data Users Manual

Contents

• 1 Preface
• 2 How to use this manual
• 3 Instrument and AOT Overview
  • 3.1 Overview
  • 3.2 Data Collection with ISOPHOT
    • 3.2.1 Signal Flow in ISOPHOT
    • 3.2.2 Cold readout Electronics (CRE)
    • 3.2.3 Detector Interface Electronics (DIE)
    • 3.2.4 readout timing control
  • 3.3 ISOPHOT measurement concept
  • 3.4 Detector Subsystems
    • 3.4.1 PHT-P
    • 3.4.2 PHT-C
    • 3.4.3 PHT-S
  • 3.5 Fine Calibration Sources (FCSs)
  • 3.6 Focal Plane Chopper (FPC)
  • 3.7 ISOPHOT Modes of Operation
    • 3.7.1 PHT-P: PHT03, PHT04, PHT05, PHT17/18/19
      • 3.7.1.1 PHT03
      • 3.7.1.2 PHT04
      • 3.7.1.3 PHT05
      • 3.7.1.4 PHT17/18/19
    • 3.7.2 PHT-C: PHT22, PHT25, PHT32, PHT37/38/39
      • 3.7.2.1 PHT22
      • 3.7.2.2 PHT25
      • 3.7.2.3 PHT32
      • 3.7.2.4 PHT37/38/39
    • 3.7.3 PHT-S: PHT40
    • 3.7.4 Polarisation Observations: PHT50, PHT51
      • 3.7.4.1 PHT50
      • 3.7.4.2 PHT51
• 4 Instrumental Characteristics
  • 4.1 Overview
  • 4.2 Detector Properties
    • 4.2.1 Detector Responsivity/Linearity
    • 4.2.2 Transient behaviour after flux change
    • 4.2.3 Drift behaviour of responsivity
    • 4.2.4 Curing Procedures
    • 4.2.5 Dark Signal and Noise
    • 4.2.6 Detector flat-fields
    • 4.2.7 Detector Saturation
  • 4.3 Features due to electronics
    • 4.3.1 Anomalous first readouts on a ramp
    • 4.3.2 CRE (ramp) linearity
    • 4.3.3 Signal dependence on reset interval
    • 4.3.4 Detector bias: de-biasing effects
    • 4.3.5 Readout Saturation
    • 4.3.6 Disturbances by Chopper Commanding
    • 4.3.7 CRE latch-up
  • 4.4 Effects of Ionizing Radiation
  • 4.5 Optical Performance
    • 4.5.1 Instrumental Footprint on the Sky
      • 4.5.1.1 PHT-C footprints
      • 4.5.1.2 PHT-P footprints
      • 4.5.1.3 PHT-S footprints
    • 4.5.2 Point source intensity fractions
    • 4.5.3 Chopper vignetting/offset
    • 4.5.4 Inhomogeneous FCS illumination
  • 4.6 Spectral performance
    • 4.6.1 PHT-S instrumental line profile
    • 4.6.2 PHT-S wavelength calibration
  • 4.7 Straylight
    • 4.7.1 Straylight during FCS calibrations
    • 4.7.2 Instrumental Straylight
      • 4.7.2.1 Near-field straylight
      • 4.7.2.2 Straylight from Sun, Earth and Moon
    • 4.7.3 Spectral Straylight
  • 4.8 Instrumental Polarisation
  • 4.9 Backgrounds
    • 4.9.1 Confusion
    • 4.9.2 Zodiacal Light
  • 4.10 Global Instrument Data
• 5 Calibrations
  • 5.1 Overview
  • 5.2 Calibration strategy
    • 5.2.1 Calibration strategy involving the FCS
    • 5.2.2 Absolute calibration of FCS
    • 5.2.3 Photometry with PHT-P and PHT-C
    • 5.2.4 Spectro-photometry with PHT-S
  • 5.3 Point sources versus extended sources
  • 5.4 Aperture calibration
  • 5.5 PHT-S wavelength calibration
  • 5.6 Photometric calibration in AOTs
    • 5.6.1 General signal derivation
    • 5.6.2 Multi-filter photometry: PHT03 and PHT22
    • 5.6.3 Mapping: PHT03, PHT22, PHT32
    • 5.6.4 Sparse maps: PHT17/18/19 and PHT37/38/39
    • 5.6.5 Multi-aperture photometry: PHT04
    • 5.6.6 Absolute photometry: PHT05 and PHT25
    • 5.6.7 PHT-S: PHT40
  • 5.7 Calibration files
    • 5.7.1 Calibration G files
    • 5.7.2 Calibration A files
• 6 Data Processing Level: Derive_ERD
• 7 Data Processing Level: Derive_SPD
  • 7.1 Overview
  • 7.2 Ramp Processing
    • 7.2.1 Discarding destructive read-outs
    • 7.2.2 Discarding disturbed non-destructive read-outs
    • 7.2.3 Discarding data with OTF or OPF ``off''
    • 7.2.4 Sorting out the different data-types
    • 7.2.5 Conversion of digitized numbers to CRE output voltages
    • 7.2.6 Discarding saturated read-outs
    • 7.2.7 Correction for non-linearities of the integration ramps
    • 7.2.8 Ramp deglitching
    • 7.2.9 Extraction of the signals and their uncertainties
  • 7.3 Signal Processing
    • 7.3.1 Reset interval correction
    • 7.3.2 Dark signal subtraction
    • 7.3.3 Determine chopper position and step number
    • 7.3.4 Signal deglitching
    • 7.3.5 Transient correction
    • 7.3.6 Averaging signals of same instrument set-up
    • 7.3.7 Obtaining the median of all photo-currents
    • 7.3.8 Correction for chopper vignetting
    • 7.3.9 Correction for chopped signal losses
    • 7.3.10 Ramp statistics in PHT SPD and Cal-A headers
  • 7.4 In-band power calibration
    • 7.4.1 Determination in-band power from FCS
    • 7.4.2 Signal to in-band power conversion for P detectors
    • 7.4.3 Signal to-in band power conversion for C detectors
    • 7.4.4 In-band power for raster maps
    • 7.4.5 Default responsivities
    • 7.4.6 Dependencies on mission dates
  • 7.5 Quality flags for SPD records
• 8 Data Processing Level: Derive_AAR
  • 8.1 Overview
  • 8.2 PHT auto analysis processing per AOT
    • 8.2.1 PHT03
    • 8.2.2 PHT04
    • 8.2.3 PHT05
    • 8.2.4 PHT17/18/19
    • 8.2.5 PHT22
    • 8.2.6 PHT25
    • 8.2.7 PHT32
    • 8.2.8 PHT37/38/39
    • 8.2.9 PHT40
  • 8.3 Common processing steps
    • 8.3.1 Read SPD header
    • 8.3.2 Read SPD record
    • 8.3.3 Determine celestial coordinates of each pixel in record
      • 8.3.3.1 Overview
      • 8.3.3.2 Extracting pointing data from IRPH
      • 8.3.3.3 Inclusion of chopper information
    • 8.3.4 Determination of the equatorial offsets of the detector centre
  • 8.4 Photometry
    • 8.4.1 Sorting out chopper plateaux
    • 8.4.2 Separation of source and background in-band power
      • 8.4.2.1 Rectangular mode
      • 8.4.2.2 Sawtooth mode
      • 8.4.2.3 Triangular mode
    • 8.4.3 Determine the in-band powers averaged over a measurement
      • 8.4.3.1 Rectangular mode
      • 8.4.3.2 Sawtooth and Triangular mode
    • 8.4.4 Staring mode
    • 8.4.5 Determine the mean off-source background
    • 8.4.6 Empirical correction for signal losses in chopped measurements
    • 8.4.7 Summation of the in-band powers of all detector pixels
    • 8.4.8 Fit two-dimensional Gaussian to point sources in the C-arrays
      • 8.4.8.1 Interpolate missing pixels
      • 8.4.8.2 Determination of Gaussian parameters
    • 8.4.9 Convert in-band power to point source flux density
      • 8.4.9.1 All AOTs except PHT40
      • 8.4.9.2 PHT40
    • 8.4.10 Convert in-band power to surface brightness
      • 8.4.10.1 All AOTs except PHT40
      • 8.4.10.2 PHT40
    • 8.4.11 Write PHT-P point source photometry product
    • 8.4.12 Write PHT-P extended source or raster photometry product
    • 8.4.13 Write PHT-C point source photometry product
    • 8.4.14 Write PHT-C extended source or raster photometry product
  • 8.5 Mapping
    • 8.5.1 Establish image pixel size
    • 8.5.2 Establish maximum image size
    • 8.5.3 Determination of the coverage by a sky sample in the image
    • 8.5.4 Binning sky samples onto image pixels
    • 8.5.5 Write image products
  • 8.6 Spectroscopy
    • 8.6.1 Write spectroscopy products
• 9 Caveats
  • 9.1 Overview
  • 9.2 Caveats on this document
  • 9.3 Status of Scientific Validation of PHT AOTs
    • 9.3.1 Validated modes in OLP Version 7
    • 9.3.2 Photometric Accuracies of Staring Modes
  • 9.4 OLP Version 7: Limitations and Caveats
    • 9.4.1 Error Calculation and Propagation
    • 9.4.2 Chopped Photometry
    • 9.4.3 Extended Source Photometry
    • 9.4.4 Spectroscopic Mode
    • 9.4.5 Validity Ranges of FCS Calibration Files
    • 9.4.6 Inhomogeneous FCS Illumination of PHT-P Apertures
    • 9.4.7 Non-geometric Aperture Beam Size Scaling
    • 9.4.8 Non-linearity of Detector Responsivity with Flux
    • 9.4.9 Detector Signal Transients
    • 9.4.10 Long Term Detector Drifts
    • 9.4.11 Missing Measurements and Chopper Correction
    • 9.4.12 Limitations in Use of PHT Color Correction Factors
    • 9.4.13 Empirical PPSF Correction Factors for Array Centered C200 Photometry
• 10 Getting Started
  • 10.1 First look at the products
  • 10.2 Further processing
• 11 Guide to Data Products
  • 11.1 Quick Reference: Synopsis of all ISOPHOT Products
    • 11.1.1 ERD Products
    • 11.1.2 SPD Products
    • 11.1.3 AAR Products
    • 11.1.4 Cal G Products: Derive_SPD
    • 11.1.5 Cal G Products: Derive_AAR
    • 11.1.6 Cal G Products: auxillary
  • 11.2 Product Types Sorted by AOT
• 12 Product Descriptions
  • 12.1 Overview
  • 12.2 ERD product types
    • 12.2.1 Rationale behind product design
    • 12.2.2 Product PPER
    • 12.2.3 Product P1ER
    • 12.2.4 Product P2ER
    • 12.2.5 Product P2ES
    • 12.2.6 Product PSER
    • 12.2.7 Product PSTA
  • 12.3 SPD product types
    • 12.3.1 Rationale behind product design
      • 12.3.1.1 General SPD header items I
      • 12.3.1.2 Filter dependent SPD header items
      • 12.3.1.3 General PHT related SPD header items II
      • 12.3.1.4 Product specific SPD header items: PHT05 and PHT25
    • 12.3.2 Product PPxS
    • 12.3.3 Product PC1S
    • 12.3.4 Product PC2S
    • 12.3.5 Product PSSS
    • 12.3.6 Product PSLS
    • 12.3.7 Product PPxA
    • 12.3.8 Product PCxA
    • 12.3.9 Product PPxD
    • 12.3.10 Product PC1D
    • 12.3.11 Product PC2D
    • 12.3.12 Pixel status flag
  • 12.4 AA product types
    • 12.4.1 Rationale behind product design
    • 12.4.2 Product PPAP
    • 12.4.3 Product PPAE
    • 12.4.4 Product PCAP
    • 12.4.5 Product PCAE
    • 12.4.6 Product PGAI
    • 12.4.7 Product PGAU
    • 12.4.8 Product PGAT
    • 12.4.9 Product PPAS
    • 12.4.10 Product PCAS
    • 12.4.11 Product PSAP
    • 12.4.12 Product PLAP
    • 12.4.13 Product PSAE
    • 12.4.14 Product PLAE
    • 12.4.15 Product PSAS
    • 12.4.16 Product PLAS
• 13 Calibration G Products
  • 13.1 Overview
  • 13.2 Observation time dependent calibration
    • 13.2.1 Product PTIMEDEP: PHT calibration time dependency
  • 13.3 DIE power calibration tables
    • 13.3.1 Product PDIE1TRANS: PHT DIE1 power calibration table
    • 13.3.2 Product PDIE2TRANS: PHT DIE2 power calibration table
  • 13.4 Selection of read-outs
    • 13.4.1 Product PSELNDR: PHT non-destructive read-out selection
  • 13.5 CRE linearisation corrections
    • 13.5.1 Product PPCRELIN: Linearisations for P1, P2, and P3
    • 13.5.2 Product PC1CRELIN: Linearisations for C100
    • 13.5.3 Product PC2CRELIN: Linearisations for C200
  • 13.6 Signal correction reset interval
    • 13.6.1 Product PP1RESETI: parameters for conversion to 1/4s reset interval for P1
    • 13.6.2 Product PP2RESETI: parameters for conversion to 1/4s reset interval for P2
    • 13.6.3 Product PP3RESETI: parameters for conversion to 1/4s reset interval for P3
    • 13.6.4 Product PC1RESETI: parameters for conversion to 1/4s reset interval for C100
    • 13.6.5 Product PC2RESETI: parameters for conversion to 1/4s reset interval for C200
  • 13.7 Detector dark signals
    • 13.7.1 Product PSDARK: PHT-S dark signals
    • 13.7.2 Product PPDARK: dark signals for detectors P1, P2, and P3
    • 13.7.3 Product PC1DARK: dark signals for detector C100
    • 13.7.4 Product PC2DARK: dark signals for detector C200
  • 13.8 Vignetting Corrections
    • 13.8.1 Product PP1VIGN: vignetting corrections for P1
    • 13.8.2 Product PP2VIGN: vignetting corrections for P2
    • 13.8.3 Product PP3VIGN: vignetting corrections for P3
    • 13.8.4 Product PC1VIGN: vignetting corrections for C100
    • 13.8.5 Product PC2VIGN: vignetting corrections for C200
  • 13.9 Correction for signal losses in chopped mode
    • 13.9.1 Product PPCHOPCOR: chopper correction factors for PHT-P
    • 13.9.2 Product PC1CHOPCOR: chopper correction factors for C100
    • 13.9.3 Product PC2CHOPCOR: chopper correction factors for C200
  • 13.10 FCS power calibration tables
    • 13.10.1 Product PP1FCSPOW: PHT-P1 FCS power calibration table
    • 13.10.2 Product PP2FCSPOW: PHT-P2 FCS power calibration table
    • 13.10.3 Product PP3FCSPOW_01/02: PHT-P3 FCS power calibration table
    • 13.10.4 Product PC1FCSPOW_01/02: PHT-C100 FCS power calibration table
    • 13.10.5 Product PC2FCSPOW_01/02: PHT-C200 FCS power calibration table
  • 13.11 PHT-P and PHT-C default responsivities
    • 13.11.1 Product PRESP_01/02: PHT default responsivities for P1, P2 and P3 detectors
    • 13.11.2 Product PC1RESP_01/02: PHT default responsivities for the C100 detector
    • 13.11.3 Product PC2RESP_01/02: PHT default responsivities for the C200 detector
  • 13.12 Array Illumination by FCS
    • 13.12.1 Product PC1ILLUM_01/02: FCS illumination for C100
    • 13.12.2 Product PC2ILLUM_01/02: FCS illumination for C200
  • 13.13 Inhomogeneous FCS illumination of PHT-P
    • 13.13.1 Product PP1FCSAP: FCS aperture correction tables for P1
    • 13.13.2 Product PP2FCSAP: FCS aperture correction tables for P2
    • 13.13.3 Product PP3FCSAP: FCS aperture correction tables for P3
  • 13.14 Wavelength dependent detector flat fields
    • 13.14.1 Product PC1FLAT: PHT C100 filter-to-filter flatfield correction
    • 13.14.2 Product PC2FLAT: PHT C200 filter-to-filter flatfield correction
  • 13.15 Point spread function corrections
    • 13.15.1 Product PPSF: point spread function corrections
  • 13.16 PHT-S Wavelength and Signal Calibration
    • 13.16.1 Product PSPECAL: PHT-S wavelength and signal calibration
  • 13.17 Conversion from power on detector to flux density
    • 13.17.1 Product PFLUXCONV: PHT-P/C power calibration
  • 13.18 Effective solid angles of apertures and pixels
    • 13.18.1 Product PPOMEGA: aperture dimensions and solid angles for P1, P2, and P3
    • 13.18.2 Product PC1OMEGA: dimensions and solid angles for C100 pixels
    • 13.18.3 Product PC2OMEGA: dimensions and solid angles for C200 pixels
  • 13.19 Colour corrections
    • 13.19.1 Product PCCBB: black body colour correction
    • 13.19.2 Product PCCMBBONE: modified black body colour correction
    • 13.19.3 Product PCCMBBTWO: modified black body colour correction
    • 13.19.4 Product PCCPOWER: Power law colour correction
• A Instrument Tables
  • A.1 Mean Filter/Aperture Specifications
    • A.1.1 PHT-P Filters
    • A.1.2 PHT-P Apertures
    • A.1.3 PHT-C Filters
    • A.1.4 Other Filterwheel Components
  • A.2 Filter Transmission Data
• B Conversion Algorithms for ERD
  • B.1 Temperature Sensors
  • B.2 Selected FCS Power
  • B.3 Focal Plane Chopper Deflection
  • B.4 Description of the pixel status flag PIXF in ERD products
• C Colour Corrections
  • C.1 Application of Tabulated Colour Correction Factors
  • C.2 Computation of Colour Correction Factors
    • C.2.1 Derivation of Flux Density Values from In-band Power Values
    • C.2.2 Flux Density Conversion Factors for Different Spectral Energy Distributions
    • C.2.3 Derivation of Colour Correction Factors from Flux Density Conversion Factors
• D Acronyms
• E Glossary
• References