001 package edu.nrao.sss.model.resource.vla;
002
003 import java.math.BigDecimal;
004 import java.util.SortedSet;
005 import java.util.TreeSet;
006
007 import edu.nrao.sss.measure.Frequency;
008 import edu.nrao.sss.measure.FrequencyUnits;
009 import edu.nrao.sss.measure.TimeDuration;
010 import edu.nrao.sss.model.resource.CorrelationProductGroupAbs;
011 import edu.nrao.sss.model.resource.CorrelatorBaseband;
012 import edu.nrao.sss.model.resource.CorrelatorSubbandAbs;
013
014 /**
015 * A subband of a VLA correlator baseband.
016 * <p>
017 * 2008-Mar-11, PM:
018 * <i>B.Butler and M.Rupen suggested that the SSS programming staff
019 * </i>not<i> spend a lot of time trying to put the WIDAR and VLA
020 * correlators under the same blanket. They suggested that, instead,
021 * we write special code for the short amount of time that we'll be
022 * dealing with the VLA. Therefore, this class may not see much use,
023 * if any, and has not been given the proper amount of QA attention.</i>
024 * <p>
025 * <b>Version Info:</b>
026 * <table style="margin-left:2em">
027 * <tr><td>$Revision: 2287 $</td></tr>
028 * <tr><td>$Date: 2009-05-07 13:54:58 -0600 (Thu, 07 May 2009) $</td></tr>
029 * <tr><td>$Author: dharland $ (last person to modify)</td></tr>
030 * </table></p>
031 *
032 * @author David M. Harland
033 * @since 2008-03-11
034 */
035 public class VlaSubband
036 extends CorrelatorSubbandAbs
037 {
038 private static final Frequency MIN_BW =
039 new Frequency("195312.5", FrequencyUnits.HERTZ);
040
041 private static final Frequency MAX_BW =
042 new Frequency("50000000.0", FrequencyUnits.HERTZ);
043
044 //TODO construct w/ default attribute values?
045
046 //============================================================================
047 // FREQUENCY
048 //============================================================================
049
050 public Frequency getMinimumBandwidth()
051 {
052 //VLA correlator basebands have only one subband, so if this subband
053 //belongs to a baseband, its minimum is the baseband's width.
054 CorrelatorBaseband bb = getContainer();
055 return bb == null ? MIN_BW.clone() : bb.getBandwidth();
056 }
057
058 public Frequency getMaximumBandwidth()
059 {
060 //VLA correlator basebands have only one subband, so if this subband
061 //belongs to a baseband, its maximum is the baseband's width.
062 CorrelatorBaseband bb = getContainer();
063 return bb == null ? MAX_BW.clone() : bb.getBandwidth();
064 }
065
066 public boolean hasDiscreteBandwidths() { return true; }
067
068 public SortedSet<Frequency> getAllowableBandwidths()
069 {
070 SortedSet<Frequency> bws = new TreeSet<Frequency>();
071 CorrelatorBaseband bb = getContainer();
072
073 if (bb != null)
074 {
075 bws.add(bb.getBandwidth());
076 }
077 else
078 {
079 double minHz = MIN_BW.toUnits(FrequencyUnits.HERTZ).doubleValue();
080
081 bws.add(new Frequency(new BigDecimal(minHz),
082 FrequencyUnits.HERTZ).normalize());
083
084 minHz *= 4.0;
085
086 double maxHz = MAX_BW.toUnits(FrequencyUnits.HERTZ).doubleValue();
087
088 //Only non-negative powers-of-two multiples of min are allowed
089 for (double hertz = minHz; hertz <= maxHz; hertz *= 2.0)
090 {
091 bws.add(new Frequency(new BigDecimal(hertz),
092 FrequencyUnits.HERTZ).normalize());
093 }
094 }
095
096 return bws;
097 }
098
099 //============================================================================
100 // QUANTIZATION
101 //============================================================================
102
103 /** Always returns an empty set. */
104 public SortedSet<Integer> getAllowableRequantizations()
105 {
106 return new TreeSet<Integer>();
107 }
108
109 /** Does nothing. */
110 public void setRequantization(int bits) { }
111
112 //============================================================================
113 // CORRELATION PRODUCTS
114 //============================================================================
115
116 /** Always returns <i>null</i>. */
117 protected VlaCorrProdGrp makeCorrelationProductGroup()
118 {
119 return null;
120 }
121 }
122
123 //============================================================================
124 // DUMMY CLASSES
125 //============================================================================
126
127 class VlaCorrProdGrp
128 extends CorrelationProductGroupAbs
129 {
130 protected void recalculateChannels() { needToRecalcChannels = false; }
131
132 @Override public TimeDuration getMinimumTotalIntegrationTime()
133 {
134 return null;
135 }
136
137 @Override public TimeDuration getTotalIntegrationTime() { return null; }
138
139 @Override public void setTotalIntegrationTime(TimeDuration td) { }
140 }