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#author("2025-06-29T09:39:38+00:00","default:astewww","astewww") #author("2025-06-29T09:43:50+00:00","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. -- ''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. Basically, this parameter should be set to (0–0). For OTF observations, if your observation stopped at, for instance, scan line 5, change the Begin–End setting to 5–0. This way, you can retrieve the OTF data from the scan that was previously interrupted. - ''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. - ''Sample Scan Table for pointing observations'': See [[this>Open-use_program/sample_tables_pointing]] page. *** 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 "[[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. (Basically Begin should set to be 0, and End to be the total number of scans.) -- ''Begin-End'': Numbers of start scan path and end scan path. (Basically, Begin should be set to be 1, and End to be the total number of scans.) -- ''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. - ''sensitivity calculator'': See [[this>_Tools/otfaste.pl]] page. *** 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
