| 1 | ===================== |
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| 2 | Scantable Description |
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| 3 | ===================== |
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| 4 | |
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| 5 | Introduction |
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| 6 | ============ |
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| 7 | |
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| 8 | The Scantable is the ASAP single-dish data container. It was designed |
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| 9 | based on the data abstraction of the PKSreader API. |
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| 10 | |
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| 11 | Schema |
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| 12 | ====== |
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| 13 | |
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| 14 | The Scantable consist of a main (casacore) Table and several sub-tables which |
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| 15 | are referenced via _id_. |
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| 16 | |
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| 17 | ---------- |
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| 18 | Main Table |
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| 19 | ---------- |
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| 20 | |
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| 21 | The main table consists of global data (keywords) and row-based data (columns) |
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| 22 | |
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| 23 | Columns |
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| 24 | ------- |
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| 25 | |
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| 26 | * **SPECTRA** - *Float(nchannel)* |
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| 27 | |
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| 28 | the spectral channel data. |
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| 29 | |
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| 30 | * **FLAGTRA** - *uChar(nchannel)* |
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| 31 | |
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| 32 | the corresponding flags |
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| 33 | |
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| 34 | * **TSYS** - *Float(nchannel)* |
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| 35 | |
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| 36 | the channel-based system temperature values |
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| 37 | |
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| 38 | * **FLAGROW** - *uInt* |
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| 39 | |
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| 40 | spectrum based flags |
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| 41 | |
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| 42 | * **TIME** - *MEpoch* |
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| 43 | |
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| 44 | The mjd time when the observation took place |
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| 45 | |
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| 46 | * **INTERVAL** - *Double* |
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| 47 | |
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| 48 | the integration time in seconds |
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| 49 | |
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| 50 | * **DIRECTION** - *MDirection* |
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| 51 | |
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| 52 | the associated direction on the sky |
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| 53 | |
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| 54 | * **AZIMUTH, ELEVATION** - *Float* |
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| 55 | |
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| 56 | the azimuth/elevation when the spectrum was collected |
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| 57 | |
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| 58 | * **SRCNAME** - *string* |
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| 59 | |
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| 60 | the name of the source observered |
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| 61 | |
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| 62 | * **SRCTYPE** - *Int* |
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| 63 | |
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| 64 | the tyep of the source, i.e. indicating if it is an on source scan or |
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| 65 | off source. This will be used for calibration |
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| 66 | |
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| 67 | * **SCANNO, BEAMNO, POLNO, IFNO, CYCLENO** - *uInt* |
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| 68 | |
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| 69 | These columns index (0-based) the respective values. |
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| 70 | |
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| 71 | * SCANNO: the number odf the scan. A scan is usually multiple integrations |
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| 72 | (cycles) |
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| 73 | |
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| 74 | * CYCLENO: the integration number within a scan (sub-scan?) |
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| 75 | |
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| 76 | * IFNO: the index of the IF (spectral window) |
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| 77 | |
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| 78 | * BEAMNO: the index of the beam (in a multibeam system) |
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| 79 | |
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| 80 | * POLNO: the index of the polarisation, e.g. XX=0, YY=1, Real(XY)=2, |
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| 81 | Imag(XY)=3 |
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| 82 | |
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| 83 | * **REFBEAMNO** - *Int* |
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| 84 | |
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| 85 | optional index of the reference beam in a multibeam obervation |
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| 86 | |
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| 87 | * **FREQ_ID, MOLECULE_ID, TCAL_ID, FOCUS_ID, WEATHER_ID, FIT_ID** |
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| 88 | |
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| 89 | |
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| 90 | ---------- |
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| 91 | Sub-Tables |
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| 92 | ---------- |
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| 93 | |
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| 94 | FREQUENCY |
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| 95 | --------- |
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| 96 | |
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| 97 | blah blah |
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| 98 | |
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| 99 | |
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| 100 | ======================== |
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| 101 | Mapping to other formats |
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| 102 | ======================== |
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| 103 | |
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| 104 | MS |
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| 105 | == |
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