TPF-I SWG Report - Exoplanet Exploration Program - NASA

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C HAPTER 5 Table 5-3. Angular Resolution (FWHM of PSF) of the Stretched X-Array Array Size Wavelength 6 μm 10 μm 18 μm 120 × 20 m 4.9 mas 8.2 mas 14.8 mas 612 × 102 m 1.0 mas 1.6 mas 2.9 mas Here we have assumed that the 6:1 aspect ratio of the array is held fixed, which simplifies the input optics on the combiner. One design option would be to allow for a variable aspect ratio. The nulling baseline length would be set according to the angle subtended by the inner habitable zone, and the imaging baseline would be made as larger as possible. Fore general astrophysics without nulling, the imaging properties of the stretched X-array are depicted in Fig. 5-26. 5.8.5 Optimized Program Completeness Each star on the TPF-I target list has a habitable zone, which scales by luminosity and is defined as the region around a star in which liquid water could exist. We model the habitable zone by populating this region with 1,000 pseudo-planets. The pseudo-planets have random inclination, eccentricity over the range [0, 0.1], and a semi-major axis in the range of 0.75 L ≤ x≤ 1.8 L . The planets are Earth-like in size and albedo. Program completeness is then defined to be the fraction of potentially observable planets that are detected over a mission. Our algorithm selects the most productive of the TPF candidate stars to observe in each week of the mission. It accounts for multiple visits, solar constraints, variable baselines, and planet orbital motion, removing many of the assumptions that were necessary in previous analyses. The procedure for this analysis is shown in Fig. 5-27. The changes to previous methods of computing completeness include temperature-dependence of the planet across the habitable zone, a more realistic exozodiacal model, a tapered, wavelength-dependent representation of the IWA, and the optimization of visit timing. We perform this optimization by evaluating stars on the completeness per time that is provided by a given observation. We calculate the curve of completeness vs. integration time fore each star determining the best array size at each point. Several example curves are shown in Fig. 5-28. The curves start out flat due to overhead and a minimum integration time needed to observe any pseudo planets. The curves rise and then flatten out at different levels depending on the stellar type and distance to the star. (the IWA limits the possible planet observations for stars that are farther.) We define an instantaneous efficiency (change in completeness per hour, i.e., the red dot indicating the slope of the completeness curve in Fig. 5-28) for all available stars. The observation time per star is then defined as the time needed to observe the star up to the slope cut off point (t 1 , t 2 or t 3 in Fig.5-28). The stars are then evaluated on net efficiency (i.e., the green dashed lines indicating overall completeness per observation time). Those stars with the largest net efficiency are then selected for a visit. 126
TPF-I F L I G H T B ASELINE D ESIGN eccentricity phase inclination argument Start next week repeat up to 3 years Determine if star is available for observation Eliminate planets that are observed with visit Evolve orrery of planets Determine stellar visits and observation time based on efficiency threshold optimization Compute SNR for every planet for every BL for every star Compute completeness for every BL for every star planets stars in list 1=available 0=observed End Program Completeness Figure 5-27. Flow diagram TPF-I completeness optimization. Pink boxes indicate inputs for the 1000 pseudo-planets. Blue boxes indicate steps in the program completeness computation. Green boxes indicate outputs. We compute completeness for every baseline (BL) for every star as a function of integration time. Completeness Star #1 Star #2 Star #3 Time t 1 t 3 t 2 Figure 5-28. Each stellar curve is composed of the portion between time = 0 and the red dot on the curve. The red dot is located at a common slope point for all stellar curves. The green dashed lines show the net efficiency of a given stellar observation. The stars with the best completeness per time (t 1 , t 2 or t 3 ) are then selected for a visit. 127
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JPL Publication 07-1 Terrestrial Pl
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Abstract Over the past two years, t
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Acknowledgements Twenty-two represe
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Table of Contents 1 Introduction...
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4.8.3 Post-Nulling Calibration.....
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6.4.5 Double Fourier Interferometry
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I NTRODUCTION 1 Introduction Over 2
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I NTRODUCTION et al. 2004), and res
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I NTRODUCTION Standard Interferomet
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I NTRODUCTION 1.4 References Angel,
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C HAPTER 2 0.7 to 1.5 AU scaled by
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C HAPTER 2 Table 2-2. Illustrative
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C HAPTER 2 Classical interferometry
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C HAPTER 2 trivial in the absence o
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C HAPTER 2 Figure 2-3. Simulated mi
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C HAPTER 2 would be in atmospheres
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C HAPTER 2 Figure 2-6. The mid-infr
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C HAPTER 2 Lines of constant stella
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C HAPTER 2 presence of zodiacal clo
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C HAPTER 2 S EZ 2π ∫ θ max ∫
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C HAPTER 2 Figure 2-11. Observation
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C HAPTER 2 Figure 2-12. Models of t
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C HAPTER 2 Beichman, C. A., Fridlun
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C HAPTER 2 2.7.4 Suitable Targets E
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C HAPTER 2 Reach, W. T., Franz, B.
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C HAPTER 3 3.1.1 Darwin/TPF-I Prope
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C HAPTER 3 clouds or an OB associat
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C HAPTER 3 Figure 3-3. Three possib
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C HAPTER 3 the circumstellar disk,
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C HAPTER 3 Figure 3-6. (Left panel)
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C HAPTER 3 Continuum interferometry
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C HAPTER 3 Figure 3-9: Simulated im
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C HAPTER 3 3.3 Conclusions Darwin/T
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C HAPTER 3 Nguyen, H. T., Kallivaya
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D ESIGN AND A R C H I T E C T U R E
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Page 89 and 90: D ESIGN AND A R C H I T E C T U R E
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Page 145 and 146: T E C H N O L O G Y R OADMAP FOR TP
Page 173 and 174: F UTURE D EVELOPMENTS 7 Preparatory
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Page 183 and 184: T E C H N O L O G Y A DVISORY C O M
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A PPENDIX C 2. Identical FACS fligh
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A PPENDIX C 2. Recall that the coef
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A PPENDIX C Once the formation has
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A PPENDIX C Figure C-3. Example of
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A PPENDIX C Figure C-4. FAST Flight
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A PPENDIX C The “true” time of
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A PPENDIX C References Cohen, S., a
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A PPENDIX D DC DCB DM DM DOCS DOD D
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A PPENDIX D NaCl NAR NASA NASTRAN N
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A PPENDIX E Appendix E TPF-I Review
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A PPENDIX F Alice Quillen, Universi
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A PPENDIX F Figure 3-1 - Original f
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