! File: 3367C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:05:09:36 coverpage: title_1: WFPC ASTROMERTRIC CALIBRATION title_2: PLATE DISTORTION, POINTING ASSISTANCE CALIBRATION. proposal_for: CAL/WFC pi_title: DR. pi_fname: ROBERTO pi_lname: GILMOZZI pi_inst: STSCI pi_country: USA pi_phone: (301)338-4760 keywords_1: ASTROMETRIC CALIBRATION OF WF/PC pi_position: I. SCIENTIST - TEL ! end of coverpage abstract: line_1: The purpose of this calibration test is to line_2: determine the plate distortions in the WFPC for line_3: assisted target acquisition for the small-aperture line_4: science instruments and for calibrating WFPC line_5: astrometric performance. The target field is line_6: observed at several overlapping positions so that line_7: many stellar separations of various sizes and line_8: position angles can be measured in different line_9: regions of each CCD. The observations provide line_10: their own PSF data. These observations are crucial line_11: for the GO observations of Pluto and Charon, and line_12: should be scheduled close to them. ! ! end of abstract general_form_proposers: lname: GILMOZZI fname: ROBERTO inst: STSCI country: USA ! lname: EWALD fname: SHAWN inst: STSCI country: USA ! lname: WHITE fname: RICHARD inst: STSCI country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: This calibration is crucial for the supporting of line_2: WFPC assisted target acquisitions. It has been line_3: shown, in fact, that the WFPC displays a line_4: substantial geometrical distortion (up to 0.2" line_5: over 20") which would impair any astrometry line_6: performed with it, and in particular any line_7: measurements intended for subsequent "blind line_8: offsets" with other, small aperture, instruments. line_9: Gilmozzi and White (1991) have however shown that line_10: it is possible to remove the distortion (at least line_11: in the area analized by them, about half of one line_12: chip) down to a level of 0.01". This proposal line_13: extends the calibration to the whole field of view line_14: of both WFC and PC, although the first step will line_15: be to calibrate only the "default" chips (W2 and ! question: 3 section: 2 line_1: P6). To do so we plan to observe a moderately line_2: crowded globular cluster in the LMC (NGC1850) for line_3: which we already have a set of observations in line_4: August and September 1990 (used for the quoted line_5: analysis). The telescope will be moved at 5 line_6: different position within the cluster so as to line_7: have the same group of stars in each quadrant and in line_8: the center of the chip. Comparing the relative line_9: positions of the stars in each sector will yield line_10: the relative distortion between sectors, which line_11: will be then tied together in the central, line_12: overlapping area. The outcome of this proposal line_13: will be a two-dimensional polinomial which will be line_14: used to correct the x,y coordinates of each chip. line_15: The use of the same target as in the study by ! question: 3 section: 3 line_1: Gilmozzi and White will allow us to check for long line_2: term stability of the distortion. The observations line_3: will be performed in the F555W filter (probably line_4: the standard for this sort of astrometric line_5: measurements). We will however check for line_6: wavelength dependence of the distortion by taking line_7: a single image in F439W (an image in the F785LP is line_8: already in hand). ! question: 4 section: 1 line_1: Instrument calibration. ! question: 5 section: 1 line_1: This is a calibration activity for which the prerequsites are that the line_2: WF/PC is UV-flooded, if we are using a flood, and the final telescope focus line_3: and collimation be adopted. ! question: 6 section: 1 line_1: Avoid the SAA for all exposures. ! question: 7 section: 1 line_1: These data will be analyzed at STScI and the results will line_2: be part of the ScI calibration data base and will be included line_3: in WF/PC Instrument Science or Target Acquisition reports. ! !end of general form text general_form_address: lname: GILMOZZI fname: ROBERTO category: PI inst: STSCI ! lname: EWALD fname: SHAWN category: CON inst: STSCI addr_1: 3700 SAN MARTIN DR. city: BALTIMORE state: MD zip: 21218 country: USA phone: 301-338-4927 ! lname: WHITE fname: RICHARD category: CON inst: STSCI addr_1: 3700 SAN MARTIN DR. city: BALTIMORE state: MD zip: 21218 country: USA phone: 301-338-4797 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC1850 descr_1: YOUNG CLUSTER pos_1: RA = 05H 08M 59S +/-1.0S, pos_2: DEC = -68D 49' 24" +/- 5.0" equinox: 1950 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.100 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 1.1-1.6 NO GAP; req_3: CYCLE 1 / 1.1-2.6; req_4: POS TARG -10,10 comment_1: AVOID SAA FOR ALL EXPOSURES. comment_2: USE SAME GUIDE STARS FOR 1.1-1.6, comment_3: IF POSSIBLE. SCHEDULE LINES 1-1.6 comment_4: DURING SAME WEEK AS PLUTO/CHARON comment_5: OBSERVATION FROM GO PROP 2215. ! linenum: 1.200 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG +10,-10 ! linenum: 1.300 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -30,-10 ! linenum: 1.400 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -30,+30 ! linenum: 1.500 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG +10,+30 ! linenum: 1.600 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F439W num_exp: 1 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=0.5, param_2: PRE-FLASH=YES ! linenum: 2.100 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 2.1-2.6 NO GAP; req_3: POS TARG -10,10 comment_1: AVOID SAA FOR ALL EXPOSURES. comment_2: USE SAME GUIDE STARS FOR 2.1-2.6, comment_3: IF POSSIBLE ! linenum: 2.200 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -26,-6 ! linenum: 2.300 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -26,26 ! linenum: 2.400 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG 6,26 ! linenum: 2.500 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG 6,-6 ! linenum: 2.600 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F439W num_exp: 1 time_per_exp: 2200S priority: 1 param_1: CR-SPLIT=0.5, param_2: PRE-FLASH=YES ! ! end of exposure logsheet ! No scan data records found