public void readOrbitData() throws IOException {
if (_productFile instanceof DorisOrbitProductFile) {
final DorisOrbitProductFile dorisProdFile = (DorisOrbitProductFile) _productFile;
final Record orbitRecord = dorisProdFile.readOrbitData();
OrbitVector orb = null;
final SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss.SSSSSS");
final ArrayList<OrbitVector> orbitVectorList = new ArrayList<OrbitVector>();
final int numFields = orbitRecord.getNumFields();
for (int i = 0; i < numFields; ++i) {
final Field f = orbitRecord.getFieldAt(i);
final String fieldName = f.getName();
if (fieldName.contains("blank")) {
continue;
} else if (fieldName.contains("utc_time")) {
orb = new OrbitVector();
try {
orb.utcTime = ProductData.UTC.parse(f.getData().getElemString()).getMJD();
} catch (ParseException e) {
throw new IllegalFileFormatException("Failed to parse UTC time " + e.getMessage());
}
} else if (fieldName.contains("delta_ut1")) {
if (orb != null) orb.delta_ut1 = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("abs_orbit")) {
if (orb != null)
orb.absOrbit = Integer.parseInt(f.getData().getElemString().replace("+", ""));
} else if (fieldName.contains("x_pos")) {
if (orb != null) orb.xPos = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("y_pos")) {
if (orb != null) orb.yPos = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("z_pos")) {
if (orb != null) orb.zPos = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("x_vel")) {
if (orb != null) orb.xVel = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("y_vel")) {
if (orb != null) orb.yVel = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("z_vel")) {
if (orb != null) orb.zVel = Double.parseDouble(f.getData().getElemString());
} else if (fieldName.contains("qual_flags")) {
if (orb != null) orb.qualFlags = f.getData().getElemString();
orbitVectorList.add(orb);
}
}
dataRecords = orbitVectorList.toArray(new OrbitVector[orbitVectorList.size()]);
recordTimes = new double[dataRecords.length];
for (int i = 0; i < dataRecords.length; i++) {
recordTimes[i] = dataRecords[i].utcTime;
}
}
}
/**
* Get orbit vector for given UTC time.
*
* @param utc The UTC time
* @throws Exception for incorrect time
* @return The orbit vector
*/
public OrbitVector getOrbitVector(double utc) throws Exception {
final int interpOrder = 8;
final int nRecords = recordTimes.length;
double t0 = recordTimes[0];
double tN = recordTimes[nRecords - 1];
// final int n = Arrays.binarySearch(recordTimes, utc);
// binary search not needed, we can pre-compute index for given utc wrt delta, and start/end
// time
final double tRel = (utc - t0) / (tN - t0) * (nRecords - 1); // data index from 0
final int itRel =
(int)
Math.max(
1, Math.min(Math.round(tRel) - (interpOrder / 2), (nRecords - 1) - interpOrder));
// indices for populating arrays - Working with 8th Order => 9 points
final int n0 = itRel;
final int n1 = itRel + 1;
final int n2 = itRel + 2;
final int n3 = itRel + 3;
final int n4 = itRel + 4; // <- closest to interpolation point
final int n5 = itRel + 5;
final int n6 = itRel + 6;
final int n7 = itRel + 7;
final int n8 = itRel + 8;
// TODO: Verify validity of check for incorrect UTC time in parsing orbit
// ....I'm not sure that this check is very smart, and that it would pick up not fully
// overlapping arc
if (n0 < 0
|| n1 < 0
|| n2 < 0
|| n3 < 0
|| n4 < 0
|| n5 > nRecords
|| n6 > nRecords
|| n7 > nRecords
|| n8 > nRecords) {
throw new Exception("Incorrect UTC time");
}
final double[] delta_ut1Array = {
dataRecords[n0].delta_ut1,
dataRecords[n1].delta_ut1,
dataRecords[n2].delta_ut1,
dataRecords[n3].delta_ut1,
dataRecords[n4].delta_ut1,
dataRecords[n5].delta_ut1,
dataRecords[n6].delta_ut1,
dataRecords[n7].delta_ut1,
dataRecords[n8].delta_ut1
};
final double[] xPosArray = {
dataRecords[n0].xPos,
dataRecords[n1].xPos,
dataRecords[n2].xPos,
dataRecords[n3].xPos,
dataRecords[n4].xPos,
dataRecords[n5].xPos,
dataRecords[n6].xPos,
dataRecords[n7].xPos,
dataRecords[n8].xPos
};
final double[] yPosArray = {
dataRecords[n0].yPos,
dataRecords[n1].yPos,
dataRecords[n2].yPos,
dataRecords[n3].yPos,
dataRecords[n4].yPos,
dataRecords[n5].yPos,
dataRecords[n6].yPos,
dataRecords[n7].yPos,
dataRecords[n8].yPos
};
final double[] zPosArray = {
dataRecords[n0].zPos,
dataRecords[n1].zPos,
dataRecords[n2].zPos,
dataRecords[n3].zPos,
dataRecords[n4].zPos,
dataRecords[n5].zPos,
dataRecords[n6].zPos,
dataRecords[n7].zPos,
dataRecords[n8].zPos
};
final double[] xVelArray = {
dataRecords[n0].xVel,
dataRecords[n1].xVel,
dataRecords[n2].xVel,
dataRecords[n3].xVel,
dataRecords[n4].xVel,
dataRecords[n5].xVel,
dataRecords[n6].xVel,
dataRecords[n7].xVel,
dataRecords[n8].xVel
};
final double[] yVelArray = {
dataRecords[n0].yVel,
dataRecords[n1].yVel,
dataRecords[n2].yVel,
dataRecords[n3].yVel,
dataRecords[n4].yVel,
dataRecords[n5].yVel,
dataRecords[n6].yVel,
dataRecords[n7].yVel,
dataRecords[n8].yVel
};
final double[] zVelArray = {
dataRecords[n0].zVel,
dataRecords[n1].zVel,
dataRecords[n2].zVel,
dataRecords[n3].zVel,
dataRecords[n4].zVel,
dataRecords[n5].zVel,
dataRecords[n6].zVel,
dataRecords[n7].zVel,
dataRecords[n8].zVel
};
final OrbitVector orb = new OrbitVector();
double ref = tRel - itRel;
orb.utcTime = utc;
orb.absOrbit = dataRecords[n1].absOrbit;
orb.qualFlags = dataRecords[n1].qualFlags;
orb.delta_ut1 = lagrangeEightOrderInterpolation(delta_ut1Array, ref);
orb.xPos = lagrangeEightOrderInterpolation(xPosArray, ref);
orb.yPos = lagrangeEightOrderInterpolation(yPosArray, ref);
orb.zPos = lagrangeEightOrderInterpolation(zPosArray, ref);
orb.xVel = lagrangeEightOrderInterpolation(xVelArray, ref);
orb.yVel = lagrangeEightOrderInterpolation(yVelArray, ref);
orb.zVel = lagrangeEightOrderInterpolation(zVelArray, ref);
/*
final double dt = (utc - recordTimes[n1]) / (recordTimes[n2] - recordTimes[n1]);
final double w0 = w(dt + 1.0);
final double w1 = w(dt);
final double w2 = w(1.0 - dt);
final double w3 = w(2.0 - dt);
final OrbitVector orb = new OrbitVector();
orb.utcTime = utc;
orb.absOrbit = dataRecords[n1].absOrbit;
orb.qualFlags = dataRecords[n1].qualFlags;
orb.delta_ut1 = w0*dataRecords[n0].delta_ut1 +
w1*dataRecords[n1].delta_ut1 +
w2*dataRecords[n2].delta_ut1 +
w3*dataRecords[n3].delta_ut1;
orb.xPos = w0*dataRecords[n0].xPos +
w1*dataRecords[n1].xPos +
w2*dataRecords[n2].xPos +
w3*dataRecords[n3].xPos;
orb.yPos = w0*dataRecords[n0].yPos +
w1*dataRecords[n1].yPos +
w2*dataRecords[n2].yPos +
w3*dataRecords[n3].yPos;
orb.zPos = w0*dataRecords[n0].zPos +
w1*dataRecords[n1].zPos +
w2*dataRecords[n2].zPos +
w3*dataRecords[n3].zPos;
orb.xVel = w0*dataRecords[n0].xVel +
w1*dataRecords[n1].xVel +
w2*dataRecords[n2].xVel +
w3*dataRecords[n3].xVel;
orb.yVel = w0*dataRecords[n0].yVel +
w1*dataRecords[n1].yVel +
w2*dataRecords[n2].yVel +
w3*dataRecords[n3].yVel;
orb.zVel = w0*dataRecords[n0].zVel +
w1*dataRecords[n1].zVel +
w2*dataRecords[n2].zVel +
w3*dataRecords[n3].zVel;
*/
return orb;
}