001 package edu.nrao.sss.model.project;
002
003 import java.util.HashMap;
004 import java.util.HashSet;
005 import java.util.Map;
006 import java.util.Set;
007
008 import edu.nrao.sss.astronomy.SkyPosition;
009 import edu.nrao.sss.model.RepositoryException;
010 import edu.nrao.sss.model.project.scan.ScanMode;
011 import edu.nrao.sss.model.source.Source;
012 import edu.nrao.sss.model.source.SourceFilter;
013 import edu.nrao.sss.model.source.SourceProvider;
014
015 /**
016 * A selector of sources that can be used for observation calibration.
017 * <p>
018 * This class has the astronomical knowledge that is needed for choosing
019 * calibrators for different goals of source observation. It is meant
020 * to act as a virtual astronomer for calibrator selection.</p>
021 * <p>
022 * TODO: At this time this class is a placeholder for later developement.</p>
023 * <p>
024 * <b>Version Info:</b>
025 * <table style="margin-left:2em">
026 * <tr><td>$Revision: 1118 $</td></tr>
027 * <tr><td>$Date: 2008-02-26 10:52:29 -0700 (Tue, 26 Feb 2008) $</td></tr>
028 * <tr><td>$Author: dharland $</td></tr>
029 * </table></p>
030 *
031 * @author David M. Harland
032 * @since 2006-06-29
033 */
034 public class CalibratorSelector
035 {
036 private Set<SourceProvider> providers;
037
038 /** Creates a new selector. */
039 public CalibratorSelector()
040 {
041 providers = new HashSet<SourceProvider>();
042 }
043
044 //============================================================================
045 // CONFIGURATION
046 //============================================================================
047
048 /**
049 * Adds {@code newProvider} to this selector's collection.
050 * The <i>find</i> methods will search all providers held by
051 * this selector.
052 *
053 * @param newProvider a source provider that this selector uses when searching
054 * for calibrators.
055 */
056 public void addProvider(SourceProvider newProvider)
057 {
058 if (newProvider != null)
059 providers.add(newProvider);
060 }
061
062 /** Removes all source providers from this selector. */
063 public void removeAllProviders()
064 {
065 providers.clear();
066 }
067
068 //A method like this would determine whether this selector returned
069 //a lot of calibrators, or only those that were determined to be
070 //of some quality level.
071 //TODO
072 //public void setStringencyLevel(... level)
073
074 //This method would set the maximum number of calibrators returned
075 //for any one type of calibration. Like the stringency level,
076 //it would help narrow the list of calibrators returned.
077 //Presumably, this method would return the highest ranked calibrators.
078 //TODO
079 //public void setMaxCalibratorCount(int max)
080
081 //============================================================================
082 // SELECTION
083 //============================================================================
084
085 /**
086 * Returns a collection of calibrators that are suitable for the given
087 * observational parameters.
088 * <p>
089 * The form of the returned collection is a map where the key is an
090 * observation mode and the value is a set of zero or more calibrator
091 * sources.
092 * The map contains keys for only those modes that are deemed
093 * necessary for the given observation parameters.</p>
094 *
095 * @param observationType
096 * @param sourcePosition
097 *
098 * @return a map whose keys are of type
099 * {@link ScanMode} and
100 * whose values are sets of {@code Source}s.
101 */
102 public Map<ScanMode, Set<Source>> findCalibratorsFor(Object observationType,
103 SkyPosition sourcePosition)
104 {
105 Map<ScanMode, Set<Source>> result =
106 new HashMap<ScanMode, Set<Source>>();
107
108 //Find the different types of calibration needed
109 Set<ScanMode> obsModes = determineObservationModes(observationType);
110
111 //For each calibration type, find good calibrators
112 for (ScanMode obsMode : obsModes)
113 {
114 Set<Source> sources = findCalibratorsFor(obsMode, observationType,
115 sourcePosition);
116 result.put(obsMode, sources);
117 }
118
119 return result;
120 }
121
122 /**
123 * Returns a collection of calibrators that are suitable for the given
124 * observational parameters.
125 * <p>
126 * The form of the returned collection is a set of zero or more calibrator
127 * sources.</p>
128 *
129 * @param observationMode
130 * @param observationType
131 * @param sourcePosition
132 *
133 * @return a collection of calibrators.
134 */
135 public Set<Source> findCalibratorsFor(ScanMode observationMode, Object observationType, SkyPosition sourcePosition)
136 {
137 Set<Source> result = new HashSet<Source>();
138
139 SourceFilter filter = configureFilterFor(observationMode, observationType, sourcePosition);
140
141 for (SourceProvider provider : providers)
142 {
143 try {
144 result.addAll(provider.getSources(filter));
145 }
146 catch (RepositoryException ex) {
147 //TODO: Decide: Remove catch & have method throw?
148 // Catch & log?
149 // Catch & convert to diff Excep type?
150 }
151 }
152
153 return result;
154 }
155
156 /**
157 * Returns a set of the observation modes needed for the given
158 * observation type.
159 *
160 * @param observationType
161 *
162 * @return a set of observation modes.
163 */
164 private Set<ScanMode> determineObservationModes(Object observationType)
165 {
166 Set<ScanMode> result = new HashSet<ScanMode>();
167
168 //TODO: Replace temp coding w/ real
169 for (ScanMode type : ScanMode.values())
170 result.add(type);
171
172 return result;
173 }
174
175 /**
176 * Returns a source filter that is configured for the given observational
177 * parameters.
178 *
179 * @param calibration
180 * @param observationType
181 * @param observationMode
182 * @param sourcePosition
183 *
184 * @return
185 */
186 private SourceFilter configureFilterFor(ScanMode observationMode, Object observationType, SkyPosition sourcePosition)
187 {
188 SourceFilter result = new SourceFilter();
189
190 //TODO: configure filter here
191
192 return result;
193 }
194 }