001 package edu.nrao.sss.model.source;
002
003 import edu.nrao.sss.astronomy.StokesParameter;
004 import edu.nrao.sss.measure.Angle;
005 import edu.nrao.sss.measure.ArcUnits;
006 import edu.nrao.sss.measure.Frequency;
007 import edu.nrao.sss.measure.FrequencyRange;
008 import edu.nrao.sss.measure.FluxDensity;
009 import edu.nrao.sss.measure.TimeDuration;
010 import edu.nrao.sss.measure.TimeInterval;
011 import edu.nrao.sss.measure.TimeUnits;
012
013 import java.math.BigDecimal;
014 import java.util.Calendar;
015 import java.util.Date;
016 import java.util.TimeZone;
017
018 /**
019 * An observation of the flux from a source performed by the
020 * Very Large Array.
021 * <p>
022 * This class was copied from edu.nrao.legacy.VLAFluxData.
023 * It has not (yet?) been altered to match more closely the
024 * style of the other classes in the SSS Domain Model.</p>
025 * <p>
026 * This class is not suggested for general use.</p>
027 * <p>
028 * <b>Version Info:</b>
029 * <table style="margin-left:2em">
030 * <tr><td>$Revision: 1314 $</td></tr>
031 * <tr><td>$Date: 2008-05-30 11:31:14 -0600 (Fri, 30 May 2008) $</td></tr>
032 * <tr><td>$Author: dharland $</td></tr>
033 * </table></p>
034 *
035 * @author David M. Harland
036 * @since 2007-05-21
037 */
038 public class VlaFluxObservation
039 implements Cloneable
040 {
041 //The names of these variables were copied directly from
042 //edu.nrao.legacy.VLAFluxData.
043 public String Source;
044 public double mjad;
045 public String correlator_mode;
046 public double el_end; //Units?
047 public double obs_start; //in Radians
048 public double obs_end; //in Radians
049 public double time_obs; //Length of obsvn? This is an mjd
050 public double ac_freq; //Right circular polarized, in Ghz
051 public double bd_freq; //Left circular polarized
052 public double ac_flux; //in Janskies
053 public double ac_flux_stddev;
054 public double bd_flux;
055 public double bd_flux_stddev;
056
057 /** Used by a factory method of SourceBrightness. */
058 SourceBrightness[] makeBrightnesses()
059 {
060 //Circular polarizations
061 final int LEFT = 0;
062 final int RIGHT = 1;
063
064 PointBrightness[] result = new PointBrightness[2];
065
066 result[LEFT] = (PointBrightness)
067 SourceBrightness.createBrightness(BrightnessDistribution.POINT);
068
069 result[LEFT].setPolarization(StokesParameter.LL);
070
071 //XXX The endpoint will have to be changed by the client of this method if
072 //they want something besides infinity.
073 TimeInterval ti = new TimeInterval();
074 ti.set(getDateFromMjad((int)this.mjad, obs_start), ti.getEnd());
075 result[LEFT].setValidTime(ti);
076
077 FrequencyRange fr = new FrequencyRange(
078 new Frequency(new BigDecimal(this.ac_freq)),
079 new Frequency(new BigDecimal(this.bd_freq))
080 );
081
082 result[LEFT].setValidFrequency(fr);
083 result[LEFT].setPeakFluxDensity(new FluxDensity(BigDecimal.valueOf(this.bd_flux)));
084
085 result[RIGHT] = (PointBrightness)result[LEFT].clone();
086 result[RIGHT].setPolarization(StokesParameter.RR);
087 result[RIGHT].setPeakFluxDensity(new FluxDensity(BigDecimal.valueOf(this.ac_flux)));
088
089 return result;
090 }
091
092 /**
093 * @return a UTC date representing this particular mjad.
094 * @param mjad A MJAD with no fractional day component
095 * @param rads A fractional day represented in radians.
096 */
097 private Date getDateFromMjad(int mjad, double rads)
098 {
099 Angle startTime = new Angle(BigDecimal.valueOf(rads), ArcUnits.RADIAN);
100 double startHour = startTime.toUnits(ArcUnits.HOUR).doubleValue();
101
102 TimeDuration start = new TimeDuration(BigDecimal.valueOf(startHour));
103 int hour = (int)start.getIntegralPart(TimeUnits.HOUR);
104 int min = (int)start.getIntegralPart(TimeUnits.MINUTE);
105
106 //Ignore anything more precise than seconds
107 int sec = start.getPart(TimeUnits.SECOND).intValue();
108
109 //Intialize the calendar to the Gregorian date that represents 0.0 MJD
110 Calendar c = Calendar.getInstance();
111 c.setTimeZone(TimeZone.getTimeZone("UTC"));
112 c.set(1858, Calendar.NOVEMBER, 17, 0, 0, 0);
113
114 //Add the days, hours, etc.
115 c.add(Calendar.DAY_OF_YEAR, mjad);
116 c.add(Calendar.HOUR_OF_DAY, hour);
117 c.add(Calendar.MINUTE, min);
118 c.add(Calendar.SECOND, sec);
119
120 return c.getTime();
121 }
122
123 /* (non-Javadoc)
124 * @see java.lang.Object#toString()
125 */
126 @Override
127 public String toString()
128 {
129 StringBuilder buff = new StringBuilder();
130
131 final String DELIM = ";";
132
133 buff.append("VLA FLUX OBSERVATION;");
134 buff.append("Source=").append(Source).append(DELIM);
135 buff.append("mjad=").append(mjad).append(DELIM);
136 buff.append("correlator_mode=").append(correlator_mode).append(DELIM);
137 buff.append("el_end=").append(el_end).append(DELIM);
138 buff.append("obs_start=").append(obs_start).append(DELIM);
139 buff.append("obs_end=").append(obs_end).append(DELIM);
140 buff.append("time_obs=").append(time_obs).append(DELIM);
141 buff.append("ac_freq=").append(ac_freq).append(DELIM);
142 buff.append("bd_freq=").append(bd_freq).append(DELIM);
143 buff.append("ac_flux=").append(ac_flux).append(DELIM);
144 buff.append("ac_flux_stddev=").append(ac_flux_stddev).append(DELIM);
145 buff.append("bd_flux=").append(bd_flux).append(DELIM);
146 buff.append("bd_flux_stddev=").append(bd_flux_stddev).append(DELIM);
147
148 return buff.toString();
149 }
150
151 /**
152 * Returns a copy of this observation.
153 * <p>
154 * If anything goes wrong during the cloning procedure,
155 * a {@code RuntimeException} will be thrown.</p>
156 */
157 @Override
158 public VlaFluxObservation clone()
159 {
160 VlaFluxObservation clone = null;
161
162 try
163 {
164 //This line takes care of the primitive & immutable fields properly
165 clone = (VlaFluxObservation)super.clone();
166
167 //There are no contained objects to clone.
168 }
169 catch (Exception ex)
170 {
171 throw new RuntimeException(ex);
172 }
173
174 return clone;
175 }
176
177 /** Returns <i>true</i> if {@code o} is equal to this observation. */
178 @Override
179 public boolean equals(Object o)
180 {
181 //Quick exit if o is this
182 if (o == this)
183 return true;
184
185 //Quick exit if o is null
186 if (o == null)
187 return false;
188
189 //Quick exit if classes are different
190 if (!o.getClass().equals(this.getClass()))
191 return false;
192
193 VlaFluxObservation other = (VlaFluxObservation)o;
194
195 return
196 other.Source.equalsIgnoreCase(this.Source) &&
197 other.correlator_mode.equalsIgnoreCase(this.correlator_mode) &&
198 other.mjad == this.mjad &&
199 other.el_end == this.el_end &&
200 other.obs_start == this.obs_start &&
201 other.obs_end == this.obs_end &&
202 other.time_obs == this.time_obs &&
203 other.ac_freq == this.ac_freq &&
204 other.bd_freq == this.bd_freq &&
205 other.ac_flux == this.ac_flux &&
206 other.bd_flux == this.bd_flux &&
207 other.ac_flux_stddev == this.ac_flux_stddev &&
208 other.bd_flux_stddev == this.bd_flux_stddev;
209 }
210
211 /** Returns a hash code value for this observation. */
212 @Override
213 public int hashCode()
214 {
215 //Taken from the Effective Java book by Joshua Bloch.
216 //The constants 17 & 37 are arbitrary & carry no meaning.
217 int result = 17;
218
219 //You must keep this method in sync w/ equals
220
221 result = 37 * result + Source.hashCode();
222 result = 37 * result + correlator_mode.hashCode();
223
224 result = 37 * result + new Double(mjad).hashCode();
225 result = 37 * result + new Double(el_end).hashCode();
226 result = 37 * result + new Double(obs_start).hashCode();
227 result = 37 * result + new Double(obs_end).hashCode();
228 result = 37 * result + new Double(time_obs).hashCode();
229 result = 37 * result + new Double(ac_freq).hashCode();
230 result = 37 * result + new Double(bd_freq).hashCode();
231 result = 37 * result + new Double(ac_flux).hashCode();
232 result = 37 * result + new Double(bd_flux).hashCode();
233 result = 37 * result + new Double(ac_flux_stddev).hashCode();
234 result = 37 * result + new Double(bd_flux_stddev).hashCode();
235
236 return result;
237 }
238 }