MSDerivedValues.h

Go to the documentation of this file.

// # MSDerivedValues.h: a server for values derived from a MS (e.g. P.A.)
// # Copyright (C) 1997,1999,2000
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef MS_MSDERIVEDVALUES_H
#define MS_MSDERIVEDVALUES_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/Vector.h>
#include <casacore/measures/Measures.h>
#include <casacore/measures/Measures/MCDirection.h>
#include <casacore/measures/Measures/MDoppler.h>
#include <casacore/measures/Measures/MFrequency.h>
#include <casacore/measures/Measures/MCEpoch.h>
#include <casacore/measures/Measures/MCRadialVelocity.h>
#include <casacore/measures/Measures/MPosition.h>
#include <casacore/ms/MeasurementSets/MeasurementSet.h>
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class MSAntennaColumns;
class String;
// <summary>
// MSDerivedValues calculates values derived from a MS
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> MeasurementSet
//   <li> SomeOtherClass
//   <li> some concept
// </prerequisite>
//
// <etymology>
// MSDerivedValues calculates values derived from those in a MS
// </etymology>
//
// <synopsis>
// MSDerivedValues is a class that computes values derived from those present
// in a MeasurementSet. E.g., calculate feed position angles on the sky from
// time, antenna positions and feed characteristics.
// </synopsis>
//
// <example>
// <srcblock>
// // calculate the parallactic angle and the observatory velocity for the
// // first time and first source in the MS.
// // set up
// MSDerivedValues msd;
// MS myMS("myMS");
// MSColumns msc(myMS);
// msd.setAntennas(msc.antenna());
// MEpoch ep=MS::epochMeasure(msc.time());
// ep.set(MVEpoch(Quantity(msc.time()(0),"s")));
// msd.setEpoch(ep);
// MDirection dir=MS::directionMeasure(msc.field().phaseDir());
// dir.set(MVDirection(Vector<Double>(msc.field().phaseDir()(0))));
// msd.setFieldCenter(dir);
// msd.setVelocityFrame(MRadialVelocity::LSRK);
// // now we are ready for the calculations:
// Double parAngle = msd.parangle();
// MRadialVelocity observatoryVel = msd.obsVel();
// </srcblock>
// </example>
//
// <motivation>
// Values derived from those in a MS are needed in various places, e.g., for
// plotting purposes. This class combines the commonly needed calculations
// in one place.
// </motivation>
//
// <thrown>
//    <li>
//    <li>
// </thrown>
//
// <todo asof="1997/05/30">
//   <li> the interface should be less cumbersome
//   <li> probably needs speeding up
// </todo>
 
class MSDerivedValues {
  friend class VisBufferAsync;  // to work around dysfunctional operator= and
                                // thread-hostile shared pointers (Jim Jacobs 111104)
 public:
  MSDerivedValues();
  ~MSDerivedValues();
 
  // Copy constructor, this will initialize with other's MS
  MSDerivedValues(const MSDerivedValues& other);
 
  // Assignment, this will initialize with other's MS
  MSDerivedValues& operator=(const MSDerivedValues& other);
 
  // Set antenna position from an antenna table
  // Returns the number of antennas. Also
  // sets the observatory position to the average of the antenna positions.
  Int setAntennas(const MSAntennaColumns& ac);
 
  // Set antenna positions, index in vector is antenna number
  // for calls below.
  MSDerivedValues& setAntennaPositions(const Vector<MPosition>& antPosition);
  const Vector<MPosition>& getAntennaPositions() const;
 
  // Set the observatory position. Note that setAntennas will reset this.
  MSDerivedValues& setObservatoryPosition(const MPosition& obsPosition);
 
  // Set antenna mounts, should have same number of entries as
  // antPosition in setAntennaPosition
  MSDerivedValues& setAntennaMount(const Vector<String>& mount);
 
  // Set epoch
  MSDerivedValues& setEpoch(const MEpoch& time);
 
  // Set field center
  MSDerivedValues& setFieldCenter(const MDirection& fieldCenter);
 
  // If you have used setMeasurementSet then this version of
  // setFieldCenter using field id makes sense
  MSDerivedValues& setFieldCenter(uInt fieldid = 0);
 
  // Set antenna index, sets the position reference for the conversions.
  // Use -1 to set the reference frame to the observatory position.
  MSDerivedValues& setAntenna(Int antenna);
 
  // Set the velocity frame type (e.g., MRadialVelocity::LSRK)
  MSDerivedValues& setVelocityFrame(MRadialVelocity::Types vType);
 
  // Set the velocity frame type (e.g., MRDoppler::RADIO)
  MSDerivedValues& setVelocityReference(MDoppler::Types dopType);
  MRadialVelocity::Types getRadialVelocityType() const;
 
  // Set the frequency frame  (e.g., MFrequency::LSRK)
  MSDerivedValues& setFrequencyReference(MFrequency::Types frqType);
 
  // get hour angle
  Double hourAngle();
 
  // get parallactic angle
  Double parAngle();
 
  // get azimuth & elevation
  const MDirection& azel();
 
  // get LAST for given time, antenna
  const MEpoch& last();
 
  // get observatory radial velocity for given epoch, position and direction
  const MRadialVelocity& obsVel();
 
  // Set an ms does not need to explicity setAntennas and is necessary if
  // setRestFreqency(fieldid, spwid) is used
  MSDerivedValues& setMeasurementSet(const MeasurementSet& ms);
 
  // Set restFrequencies...make it look for it for the fieldid, spwid and line
  // number defined in the SOURCE table return False if it fails to find the
  // restFrquency
  Bool setRestFrequency(const Int fieldid, const Int spwid, const Int linenum = 0);
 
  //
  MSDerivedValues& setRestFrequency(const Quantity& restFreq);
 
  // get frequency from velocity
 
  Quantity toFrequency(const Quantity& vel, const Quantity& restFreq);
  Quantity toFrequency(const Quantity& vel);
 
  // get velocity from frequency
  Quantity toVelocity(const Quantity& freq, const Quantity& restFreq);
  Quantity toVelocity(const Quantity& freq);
 
 protected:
 private:
  // initialize data
  void init();
 
  Int antenna_p;
  MEpoch::Convert cUTCToLAST_p;
  Vector<MPosition> mAntPos_p;
  MDirection::Convert cRADecToAzEl_p;
  MDirection::Convert cHADecToAzEl_p;
  MDirection::Convert cRADecToHADec_p;
  MeasFrame fAntFrame_p;
  MDirection mRADecInAzEl_p;
  MDirection mHADecPoleInAzEl_p;
  MDirection mFieldCenter_p;
  MPosition mObsPos_p;
  MRadialVelocity::Convert cTOPOToLSR_p;
  MDoppler::Ref velref_p;
  MFrequency::Ref frqref_p;
  Bool hasMS_p;
  Quantity restFreq_p;
  Vector<Int> mount_p;
  MeasurementSet ms_p;
  MRadialVelocity::Types radialVelocityType_p;
 
  //  Vector<Double> receptorAngle_p;
};
 
}  // namespace casacore
 
#endif