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This document provides an overview of HDAC's status in 2004, including observations, sensitivity changes, and modulation analysis. The data sets and measurements are analyzed to understand the modulation modes and potential causes of sensitivity changes. Open problems and next steps for optimizing HDAC performance are also discussed.
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HDAC Status 2004: • ~450 data sets in Jun. 2004 • ~2700 data sets in Jan. 2005 • HDAC run in photometer mode most of the time, slow sensitivity decrese, • 9 modulation measurements, switching filaments • Important observations in 2004: • LISM modulation, switching filaments • Phoebe, Titan, Saturn, … • “Systemscans”
HDAC Status: • Radiometry • Small sensitivity changes over the whole year 2003/4 • Hot Model fits data • Sensitivity is about 50 c/s/R
HDAC Status: • Radiometry • Analysed data from IPHSURVEY sequences • Looking for data, which are constant within a sequence
HDAC absolute sensitivity: HDAC sensitivity 2002 (no break-ins)
HDAC absolute sensitivity: absolute sensitivity stabilized ... ~ 60 counts/sec/R
HDAC Status: • Radiometry • Analysed data from IPHSURVEY sequences • Data, which are constant within the sequence • Analysed the variance / mean value – relation • n … number of incoming photons • m … measured value • µ … “Sensitivity”
HDAC Status: • Radiometry • Analysed the variance / mean value – relation
HDAC Status: • Radiometry • Analysed the variance / mean value – relation
HDAC Status: • Radiometry • HDAC Sensitivity from FUV data (IPHSURVEY)
HDAC Status: • Radiometry (see: HK_EVAL_NEW.PRO) • Analysed the variance / mean value – relation • Decrease of variance / mean value of 75% every year • Overall HotModel factor • 2003 – 63 • 2004 – 53 • Additional model inputs from sun exitation changes • Open problems: • Absolute sensitivity change in comparison to FUV • (FUV, absolute spectral response)
Modulation mode: • H and D-Cell Modulation lower than expected • Shape of the modulation curve is different Derived a new Power-Tau-relation from all existing measurements • Results: • Describes all measurements • Stable situation for the last 3 years • Possible reasons: • Loss of Hydrogen and/or change of dissociation rate • Filament or wall dependent
HDAC modulation analysis: Results: no differences using the filaments 2 instead of filaments 1 The additional signal by switching on the D cell is still there Decided to switch back to filaments 1
2004-030T01:54:56.0 192.307 -79.1874 -2.08658 8.57658 -0.0508378 2004-059T01:51:32.0 37.0632 76.4367 -2.18278 8.59764 -0.0500043
HDAC modulation analysis: 7 * HDAC conditioning in 2004 2004-114T02:51:30.49500 2004-136T19:00:36.71475 2004-138T11:24:36.76589 2004-140T18:47:42.46509 2004-157T17:46:41.90646 2004-184T12:22:41.81400 2004-318T08:25:36.37405
HDAC modulation: • New program for HDAC modulation analysis • Integrates HotModel & Spice
HDAC modulation: • New program for HDAC modulation analysis • Integrates HotModel & Spice • Next steps: • Optimizing parameters • Accuracy estimation • sEstm = 0.0379 A • sLISM = 0.0391 A • Diff 1 mA • (1215.664 A, 1215.34 A)
HDAC modulation analysis: Modulation analysis only works for H-modulation Problem: Influence of the D-Cell (radiation of D-filament) Between 20% & 30%
HDAC modulation analysis: Modulation analysis only works for H-modulation Problem: Influence of the D-Cell (radiation of D-filament) Between 20% & 30% Sometimes there is no additional Signal Result: See Result.xls
HDAC modulation: Korrekturversuch [1d2, 2d2, 5d2, 5d2, 9d2, 22d2, 26d2, 33d2]
HDAC modulation: Korrekturversuch [1d2, 2d2, 5d2, 5d2, 9d2, 22d2, 26d2, 33d2]
HDAC modulation: Temperaturrekonstruktion Funktioniert oft nicht! [1d2, 2d2, 5d2, 5d2, 9d2, 22d2, 26d2, 33d2]
HDAC modulation analysis: HDAC modulation measurements during the other Titan observations until end of mission Need to compare the HDAC data with FUV data (HDAC's red tail sensitivity)
Titan: 2005-12-26T18 Problem: New tour kernel Old pointing
Titan: 2006-10-25T15 2006-12-12T11 2006-12-28T10 2007-01-29T07 2007-08-31T06 2008-05-28T08
Titan Modulation Data 2004-184T 2005-090T08
Titan Limb Measurements
Titan Off-Axis Response
Titan Limb Scan
Titan Limb Scan Ergebnis
Data Analysis: • Phoebe
Data Analysis: • Phoebe
Data Analysis: • Phoebe • FUV-Data HDAC spectral sensitivity
HDAC Events: TITAN Dist = 110.000 km Phase Angle = 1° MV 26 kc MV 450 R (?)
HDAC Events: SATURN Dist = 324.937 km Phase Angle =9.3° MW 50 kc MW 900 R (?)
HDAC Events: SATURN System Scan
HDAC Open Problems for 2005: • Absolute sensitivity and comparison to FUV • FUV Data handling (more or less solved) • Applying sensitivity from Bill • Long time investigation of HDAC - Sensitivity • Saturn – Orbit System Scan • Saturn – Limb(?) san • Find out Orbit-situation • Titan Limb-Scan • Titan Modulation
HDAC Open Problems for 2005: • SATURN • Absolute sensitivity and comparison to FUV • FUV Data handling (more or less solved) • Applying sensitivity from Bill • Long time investigation of HDAC - Sensitivity • Saturn – Orbit System Scan • Find out Orbit-situation • Titan Limb-Scan • Titan Modulation