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#author("2021-05-27T15:37:55+09:00","default:astewww","astewww") #author("2021-05-27T15:40:09+09:00","default:astewww","astewww") [[Open-use_program/aobs]] :Table of contents| #contents ---- #br ** 4. Parameters of "Scan Table" in Line Observations [#sbbd6ed2] *** 4.1 Common parameters [#g13aff75] CENTER:&ref(aobs_scanl.png,,); &br; Fig 4.1 Scan Table Window - ''File Name'': Name of "Scan Table" to save. - ''On Positions'' -- ''Scan Pattern'': Select a scan pattern from the list shown by pushing the button. A window to set parameters appears except for Center (one-point). --- ''Center (one-point)'': To observe the coordinate of one source position defined in "Source Table". --- ''5 Points'': To observe 5 (or 9) points like a cross. This pattern is mainly used for pointing. --- ''Strip'': To observe equally spaced points along a strip. --- ''Map (single-grid)'': To observe a rectangular area with a single grid spacing. --- ''Random Positions'': To observe random positions. Coordinates of 40 ON positions can be defined. --- ''Spiral'': To observe a square area with a single grid spacing like a spiral from the center. --- ''OTF'': To observe a rectangular area with On-The-Fly (OTF) method. -- ''Integration Time'': Integration time for ON position. -- ''On Point Numbers'': Numbers of start point and end point of ON positions. If you observe all ON positions defined in Scan Pattern, enter "1-total number of ON positions". You can observe some specified ON positions among the positions defined in Scan Pattern by using this parameter. - ''Off/Calib Positions'' -- ''Coordinate System'': Coordinate system for OFF positions. -- ''Coordinate Mode'': Definition of OFF positions. --- ''offset from center'': Offset from the coordinate of a source defined in "Source Table". --- ''absolute value'': Absolute value on the specified coordinate system. -- ''Coordinate Values (1) - (4)'': Coordinates of OFF positions. 4 OFF positions can be defined. For frequency switching and beam switching, OFF position (1) is used for calibration. -- ''Integration Time'': Integration time for OFF position. - ''Sequence'': Observation sequence is defined by On Point Numbers, Sequence Pattern, and Number of Sequence (see examples). -- ''Sequence Pattern'': Sequence pattern of ON positions (*) and OFF positions (1 - 4). -- ''Number of Maps'': Total number of scan per one ON position. - ''Calibration'': Parameters for intensity calibration. -- ''Calibration Mode'': Select a calibration system for intensity calibration. --- ''R-SKY'' : Default -- ''Integration Time'': Integration time for calibration. In general, this is set to be the same as the integration time of ON position. -- ''Interval'': Number of Sequence Pattern between intensity calibrations. Typical value of the interval time of the calibration is 10-20 min. You should decide this parameter considering the weather condition. - ''Switching Mode Options'': You can use only position switching mode. -- ''Frequency Switch'': (Not available) *** 4.2 Scan pattern - 5 Points [#vbb2f3dc] CENTER:&ref(aobs_scanl_five.png,,); &br; Fig 4.2 5 Points Window - ''Observation Mode'': For pointing observation, select pointing. - ''Coordinate System'': Coordinate system of scan. - ''Number of Positions'': Number of ON positions. Since the center is observed twice in one cycle, total number of ON positions is 6 for 5 points and 10 for 9 points (9 points observation is not available now). - ''Grid Spacing 1'': Position offset (of the inner points for 9 points) from the center. - ''Grid Spacing 2 (for 9 points)'': Position offset of the outer points from the center. - ''Position Angle:'' Position angle of scan on the specified coordinate system. (+ : CCW) CENTER:&ref(aobs_scanl_five-pat.png,,); &br; Fig 4.3 Scan pattern of the above Scan Table. *** 4.3 Scan pattern - Strip Scan [#r8d036ff] CENTER:&ref(aobs_scanl_strip.png,,); &br; Fig 4.4 Strip Scan Window - ''Coordinate System'': Coordinate system for ON positions. - ''Number of Grid'': Number of ON position. - ''Grid Spacing'': Grid spacing of ON positions. You can enter only positive (+) value. - ''Position Angle'': Position angle of a strip of ON positions on the specified coordinate system. (+ : CCW) - ''Reference Position'': Coordinates of the reference position (*). The origin is the coordinate of a source defined in "Source Table". CENTER:&ref(aobs_scanl_strip-pat.png,,); &br; Fig 4.5 Scan pattern of the above Scan Table. *** 4.4 Scan pattern - Map (single-grid) [#k6e5cc12] CENTER:&ref(aobs_scanl_singrid.png,,); &br; Fig 4.6 Map (single-grid) Window - ''Coordinate System'': Coordinate system for ON positions. - ''Number of Grid'': Grid numbers along X and Y axes. Total number of ON positions must be less than 10000. - ''Grid Spacing'': Grid spacing of X and Y directions. Scan direction is defined by +/- (A positive (+) value is recommended because it has some bugs when a negative value (-) is entered). - ''Initial Direction'': Initial direction of scan. - ''Position Angle'': Position angle of a map on the specified coordinate system. (+ : CCW) - ''Reference Position'': Coordinates of the reference position (*). The origin is the coordinate of a source defined in "Source Table". //CENTER:&ref(aobs_scanl_sigrid-pat.png,,); //&br; //Fig 4.7 Scan pattern of the above Scan Table. *** 4.5 Scan pattern - Random Positions [#nb28714f] CENTER:&ref(aobs_scanl_ranpos.png,,); &br; Fig 4.8 Random Position Window - ''Coordinate System'': Coordinate system for ON positions. - ''Point (1) - (20)'': Coordinate of ON positions. 20 ON positions can be defined. - ''Position Angle'': Position angle of a map on the specified coordinate system. (+ : CCW) *** 4.6 Scan pattern -Spiral Scan [#mb852a16] CENTER:&ref(aobs_scanl_spiral.png,,); &br; Fig 4.9 Spiral Scan Window - ''Coordinate System'': Coordinate system for ON poisition. - ''Number of Grid'': Grid number (N) of one side of map from the reference position (*). The total number of one side of map will be set to be 2N+1. - ''Grid Spacing'': Grid spacing of ON positions. - ''Spiral Direction'': Initial direction of scan. - ''Position Angle'': Position angle of initial direction of scan. (+ : CCW) - ''Reference Position'': Coordinate of the start position. The origin is the coordinate of a source defined in "Source Table". //CENTER:&ref(aobs_scanl_spiral-pat.png,,); //&br; //Fig 4.10 Scan pattern of the above Scan Table. *** 4.7 Scan pattern - OTF [#x416287d] Detailed information is "[[HERE>http://aste.nao.ac.jp/guide/prepare/aobs/otf/obs.html]]". Detailed information is "[[A Guide to OTF Observations with ASTE>http://aste.nao.ac.jp/guide/otf/index-e.html]]". CENTER:&ref(aobs_scanl_otf.png,,); &br; Fig 4.11 OTF (raster) Window -''Coordinate System'': Coordinate system for ON position. -''Scan'': -- ''dX0, dY0'': Coordinate of the start point of a map (not include Approach). -- ''Direction'': Direction of scan (X or Y). -- ''Length'': Length of main scan path. Approach is not included. Scan direction is defined by +/- (cf. Fig 4.16). -- ''Spacing'': Spacing between scan paths. Direction of the next scan path is defined by +/-. -- ''Begin-End'': Numbers of start scan path and end scan path. -- ''Position Angle'': Position angle of a map on the specified coordinate system. (+ : CCW) - ''Time'': -- ''Approach'': Time for acceleration. -- ''Scan'': Scan time of main scan path. Scan speed of the antenna is Scan Length/Scan Time. The typical scan speed is 10-20 arcsec/s. -- ''Transit'': Transit time to start point of the next scan path. -- ''Return'': Time to return to the start point. CENTER:&ref(aobs_scanl_otf-pat.png,,); &br; Fig 4.12 Scan pattern of the above Scan Table. *** 4.3 Tips [#m21d0b6e] - Total number of ON position -- Center (one-point) : 1 -- Map (single-grid) : X Grid Number * Y Grid Number -- Map (multi-grid) : (X Grid Number * Y Grid Number : Smalll Grid) * (X Grid Number * Y Grid Number : Large Grid) -- Five points : 6 or 10 -- Spiral scan : N = (Side Grid Number)2 or {(INT)(Area Side Length / Grid Spacing)}2 &br; If N = even, N = (Side Grid Number + 1)2 or {(INT)(Area Side Length / Grid Spacing) + 1}2 - Observation sequence e.g.1) On Point Numbers : 1-4 Sequence Pattern : 1** Number of Sequence : 2 OFF1, ON1, ON2, OFF1, ON1, ON2, OFF1, ON3, ON4, OFF1, ON3, ON4 - e.g.2) On Point Numbers : 1-4 Sequence Pattern : 1**1** Number of Sequence : 2 OFF1, ON1, ON2, OFF1, ON3, ON4, OFF1, ON1, ON2, OFF1, ON3, ON4 - e.g.3) On Point Numbers : 2-6 Sequence Pattern : 1**2** Number of Sequence : 2 OFF1, ON2, ON3, OFF2, ON4, ON5, OFF1, ON6, ON2, OFF2, ON3, ON4, OFF1, ON5, ON6
