ObsInfo.h

Classes

ObsInfo -- Store miscellaneous information related to an observation. (full description)
Global Functions -- Global functions (full description)

class ObsInfo : public RecordTransformable

Interface

Public Members
ObsInfo()
~ObsInfo()
ObsInfo(const ObsInfo &other)
ObsInfo &operator=(const ObsInfo &other)
String telescope() const
ObsInfo& setTelescope(const String &telescope)
String observer() const
ObsInfo& setObserver(const String &observer)
MEpoch obsDate() const
ObsInfo& setObsDate(const MEpoch &obsDate)
MVDirection pointingCenter() const
ObsInfo& setPointingCenter (const MVDirection& direction)
Bool isPointingCenterInitial () const
virtual Bool toRecord(String & error, RecordInterface & outRecord) const
virtual Bool fromRecord(String & error, const RecordInterface & inRecord)
Bool toFITS(String & error, RecordInterface & outRecord) const
Bool fromFITS(Vector<String>& error, const RecordInterface & inRecord)
static String defaultTelescope()
static String defaultObserver()
static MEpoch defaultObsDate()
static MVDirection defaultPointingCenter()
static Vector<String> keywordNamesFITS()
Private Members
void copy_other(const ObsInfo &other)

Description

Review Status

Date Reviewed:
yyyy/mm/dd

Prerequisite

Synopsis

This class is used to record miscellaneous information about an observation. At present it contains the following:
  1. Telescope name
  2. Observer name
  3. Observation date
  4. Pointing centre (as distinct from the phase center or tangent point)
This list can easily be extended if necessary.

This class has functions to interconvert with a record in a "lossless" fashion, and to also interconvert between a record that contains a list of FITS keywords.

Example

The interface is a simple get/set interface. Note that the "set" methods can be chained together since each set method returns a reference to its object (rather like cout).
    ObsInfo oi;
    oi.setTelescope("VLA").setObserver("Glendenning");
    ...
    cout << "The date observed is: " << oi.obsDate() << endl;

Motivation

Record information to allow more full measures conversion, e.g. topo->lsr requires observatory location and time. Also record in a typesafe way image summary information users are used to from classic AIPS.

To Do

Member Description

ObsInfo()

Default constructor makes an object where all the parameters are set to their default values (see below)

~ObsInfo()

Destructor

ObsInfo(const ObsInfo &other)
ObsInfo &operator=(const ObsInfo &other)

Copy all fields from "other" to this object. Uses copy semantics.

String telescope() const
ObsInfo& setTelescope(const String &telescope)

Telescope identifier. If this is a "standard" telescope, you should use the same name as is available in the Observatories method of class MeasTable. Defaults to "UNKNOWN".

String observer() const
ObsInfo& setObserver(const String &observer)

The name (or initials) of the observer. Defaults to "UNKNOWN".

MEpoch obsDate() const
ObsInfo& setObsDate(const MEpoch &obsDate)

When was the observation taken (start time)? This is somewhat problematical for observations which are taken at multiple epochs. You should use the start time of the first sample. The default is the MEpoch default: MJD 0 UTC

MVDirection pointingCenter() const
ObsInfo& setPointingCenter (const MVDirection& direction)

What was the pointing centre, as distinct from the phase centre ? This value is specified as an MVDirection. This means it is you, the callers responsibility, to know what its reference type is in order to turn it into an MDirection. The default is (0,0) (or [1,0,0]). After you have called setPointingCenter, the function isPointingCenterInitial will return False.

Bool isPointingCenterInitial () const

Because the default pointing center is a valid value (0,0), this function is available to tell you whether the pointing center has been set (with setPointingCenter) to some value other than its initial (return False)

virtual Bool toRecord(String & error, RecordInterface & outRecord) const
virtual Bool fromRecord(String & error, const RecordInterface & inRecord)

Functions to interconvert between an ObsInfo and a record. These functions are inherited from class RecordTransformable. As new fields get added to ObsInfo these functions should be augmented. Missing fields should not generate an error to in fromRecord to allow for backwards compatibility - null values should be supplied instead. The field names are "observer", "telescope", "obsdate", and "pointingcenter"

Bool toFITS(String & error, RecordInterface & outRecord) const
Bool fromFITS(Vector<String>& error, const RecordInterface & inRecord)

Functions to interconvert between an ObsInfo and FITS keywords (converted to a Record). For the pointing center, the FITS keywords OBSRA and OBSDEC are used. Failure of fromFITS should probably not be regarded as fatal as the default ObsInfo values are viable. For each item contained in the ObsInfo, an attempt to decode it from FITS is made. If any of them fail, False is returned, but it attempts to decode them all. For those that fail an error message is held in error in the order telescope (error(0)), observer (error(1)), date (error(2)), pointing center (error(3)). error will be returned of length 0 if the return value is True, else it will be length 4.

static String defaultTelescope()
static String defaultObserver()
static MEpoch defaultObsDate()
static MVDirection defaultPointingCenter()

In some circumstances it might be useful to know what the defaults for the various values are so you can check if they have been set.

static Vector<String> keywordNamesFITS()

It might be useful to know what FITS keyword names are used in to/from FITS so we can remove them so they won't be used more than once. The names are in lower case.

void copy_other(const ObsInfo &other)

True when ObsInfo contructed. False after setPointingCenter called

Common copy ctor/assignment operator code.


Global functions (source)

Interface

ostream &operator<<(ostream &os, const ObsInfo &info)

Description

Member Description

ostream &operator<<(ostream &os, const ObsInfo &info)

Output declaration - useful for debugging.