! File: 3311C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:02:36:13 coverpage: title_1: STRUCTURE AND COMPOSITION OF TITAN'S ATMOSPHERE: CYCLE 2 sci_cat: SOLAR SYSTEM sci_subcat: MINOR PLANETS proposal_for: GTO/OS cont_id: 1289 pi_fname: JOHN pi_mi: J. pi_lname: CALDWELL pi_inst: YORK UNIVERSITY pi_country: CANADA pi_phone: (416) 665-5449 keywords_1: TITAN, ATMOSPHERIC CHEMISTRY hours_pri: 3.00 num_pri: 1 pi_position: PROFESSOR ! end of coverpage abstract: line_1: Titan will be observed both with ultraviolet and near infrared imaging and line_2: with ultraviolet spectroscopy. The near infrared imaging includes both the CH line_3: 4 line_4: band at 8890A and the nearby continuum, with a very broad-band filter for the line_5: latter. These wavelengths were not covered by the previous Voyager imaging. line_6: The CH band images may show atmospheric structure not otherwise visible, line_7: 4 line_8: because of the high opacity at this wavelength. The continuum image may line_9: actually sample the surface of Titan because the opacity there may be much line_10: lower than at other accessible wavelengths. The ultraviolet imaging is to look line_11: for very high altitude atmospheric structure that might be associated with line_12: details of the ultraviolet spectroscopy (which will itself have not spatial line_13: resolution). The ultraviolet spectroscopy will include a search for discrete line_14: absorption features, including those of CO, as well as continuum Rayleigh line_15: scattering from the atmosphere. Rayleigh scattering has not previously been line_16: detected from Titan, despite the very thick atmosphere there, because of strong line_17: absorption by quasi-organic material. ! ! end of abstract general_form_proposers: lname: CALDWELL fname: JOHN mi: J. inst: YORK UNIVERSITY country: CANADA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: The observations include three images and two spectra. The first image will be line_2: used for interactive acquisition of the spectra. The spectrarequire the prior line_3: completion and assimilation of the SV test "Spectrograph RedLeak Test." ! question: 4 section: 1 line_1: ST observations are required for their high spatial resolution, and for access line_2: to the ultraviolet between 2000 and 3000 A. Ground-based observations are line_3: completely irrelevant to this study. ! question: 5 section: 1 line_1: An interactive acquisition is probably necessary. Otherwise,there are no line_2: special scheduling requirements. ! question: 6 section: 1 line_1: There are no special requirements of these types. ! question: 7 section: 1 line_1: The images will be examined for suggestions of contrast features at all line_2: wavelengths, and will be compared to earlier Voyager images.The spectra will line_3: be divided by a published Solar spectrum to generate an albedo curve, which line_4: will be examined for discrete absorption features, includingCO at 2060 A. The line_5: continuum reflectivity will also be compared to atmospheric models. It should line_6: be possible to estimate the altitude of the ultraviolet absorbing layer, line_7: because the continuum opacity, which is Rayleigh scattering,can be modelled line_8: very accurately. ! question: 8 section: 1 line_1: There are no special requirements ! question: 10 section: 1 line_1: We expect to have access to a VAX computer from the engineering department at line_2: SUNY, to supplement the resources of the ST ScI. ! question: 13 section: 1 line_1: Ultraviolet spectroscopy and both ultraviolet and near infrared imaging of line_2: Tital will be obtained. The imaging complements the Voyager data set, at line_3: different wavelengths, where the atmosphere is known to absorb very strongly line_4: (methane bands, uv) and where it may be somewhat transparent( between methane line_5: bands). The spectra will be analyzed for discrete absorptionfeatures (such as line_6: CO) and for continuum Rayleigh scattering, which has not yetbeen detected line_7: because of strong aerosol scattering. ! !end of general form text general_form_address: lname: CALDWELL fname: JOHN mi: J. category: PI inst: YORK UNIVERSITY ! ! end of general_form_address records ! No fixed target records found solar_system_targets: targnum: 1 name_1: TITAN descr_1: SATELLITE TITAN lev1_1: STD = SATURN lev2_1: STD = TITAN wind_1: SEP OF TITAN SATURN FROM EARTH GT 30" fluxnum_1: 1 fluxval_1: V=8.4 fluxnum_2: 2 fluxval_2: F(2200)=4.5E-15 fluxnum_3: 3 fluxval_3: F(2000)=5E-16 ! targnum: 2 name_1: GANYMEDE descr_1: SATELLITE GANYMEDE lev1_1: STD = JUPITER lev2_1: STD = GANYMEDE fluxnum_1: 1 fluxval_1: V=4.6, TYPE=G8V fluxnum_2: 2 fluxval_2: F(2116)=9E-14 fluxnum_3: 3 fluxval_3: F(2500)=5E-14 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 3.000 targname: TITAN config: FOC/96 opmode: IMAGE aperture: 512X512 sp_element: F220W,F231M num_exp: 4 time_per_exp: 30M s_to_n: 20 fluxnum_1: 2 priority: 1 req_1: GUID TOL 0.05"; CYCLE 2; req_2: CONDITIONAL IF TAC OK ! linenum: 3.100 targname: TITAN config: HRS opmode: ACCUM aperture: 2.0 sp_element: G200M wavelength: 2060 num_exp: 8 time_per_exp: 30M s_to_n: 20 fluxnum_1: 3 priority: 1 req_1: GUID TOL 0.1"; CYCLE 2; req_2: CONDITIONAL IF TAC OK ! linenum: 3.200 targname: GANYMEDE config: HRS opmode: ACCUM aperture: 2.0 sp_element: G200M wavelength: 2060 num_exp: 2 time_per_exp: 30M s_to_n: 20 fluxnum_1: 3 priority: 1 req_1: GUID TOL 0.1"; CYCLE 2; req_2: CONDITIONAL IF TAC OK ! linenum: 5.000 targname: TITAN config: FOS/BL opmode: ACCUM aperture: 1.0 sp_element: G190H wavelength: 1900 num_exp: 1 time_per_exp: 2H s_to_n: 27 fluxnum_1: 3 priority: 1 req_1: GUID TOL 0.1"; CYCLE 2 comment_1: DEPENDS ON THE SV "SPECTROGRAPH RED comment_2: LEAK TEST" PROP NO. 1343. ! ! end of exposure logsheet ! No scan data records found