def compute_piercings(ns, source_list, stations=None):
"""Creates nodes to compute the "piercing points" of each
source in source_list, for each antenna in array."""
stations = stations or Context.array.stations()
xyz = Context.array.xyz()
radec0 = Context.observation.phase_centre.radec()
# project our stations into an ionospheric coordinate system xyz1
# for now, we just project everything to z=0, and take station 1 as origin
for p in stations:
# xyz_proj gives positions projected to equatorial plane (z=0)
xyzp = ns.xyz_proj(p) << Meq.Paster(xyz(p), 0, index=2)
# xyz1 gives positions relative to station1
xyz1 = ns.xyz1(p) << xyzp - ns.xyz_proj(stations[0])
# and extract the xy1 component
ns.xy1(p) << Meq.Selector(xyz1, index=[0, 1], multi=True)
# if ionosphere is "stuck" to the sky, we need to rotate the antenna
# coordinates as we go along. Otherwise we need to rotate the piercing
# coordinates. The angle of rotation is given by the P.A. _at the
# projected antenna positions_.
if iono_rotate:
ns.pa0 << -Meq.ParAngle(xyz=ns.xyz_proj(stations[0]), radec=radec0)
ns.P0 << Jones.define_rotation_matrix(ns.pa0)
for p in stations:
# if ionosphere is stuck to the sky, rotate antenna coordinates by P0
if iono_rotate:
ns.xy_r(p) << Meq.MatrixMultiply(ns.P0, ns.xy1(p))
else:
# else create P (p/a rotation matrix)
ns.pa(p) << -Meq.ParAngle(xyz=ns.xyz_proj(p), radec=radec0)
ns.P(p) << Jones.define_rotation_matrix(ns.pa(p))
for src in source_list:
lm = src.direction.lm()
lm_sq = ns.lm_sq(src.name) << Meq.Sqr(lm)
# dxy is the relative X,Y coordinate of the piercing point for this source,
# relative to centre. In each direction it's to H*tg(alpha), where
# alpha is the direction of the source w.r.t. center (i.e., arccos l).
ns.dxy(src.name) << H * lm / Meq.Sqrt(1 - lm_sq)
# now compute absolute piercings per source, per antenna
for p in Context.array.stations():
if iono_rotate:
ns.pxy(src.name, p) << ns.xy_r(p) + ns.dxy(src.name)
else:
ns.pxy(src.name, p) << ns.xy1(p) + Meq.MatrixMultiply(
ns.P(p), ns.dxy(src.name))
return ns.pxy
def compute_piercings (ns,source_list,stations=None):
"""Creates nodes to compute the "piercing points" of each
source in source_list, for each antenna in array.""";
stations = stations or Context.array.stations();
xyz = Context.array.xyz();
radec0 = Context.observation.phase_centre.radec();
# project our stations into an ionospheric coordinate system xyz1
# for now, we just project everything to z=0, and take station 1 as origin
for p in stations:
# xyz_proj gives positions projected to equatorial plane (z=0)
xyzp = ns.xyz_proj(p) << Meq.Paster(xyz(p),0,index=2);
# xyz1 gives positions relative to station1
xyz1 = ns.xyz1(p) << xyzp - ns.xyz_proj(stations[0]);
# and extract the xy1 component
ns.xy1(p) << Meq.Selector(xyz1,index=[0,1],multi=True);
# if ionosphere is "stuck" to the sky, we need to rotate the antenna
# coordinates as we go along. Otherwise we need to rotate the piercing
# coordinates. The angle of rotation is given by the P.A. _at the
# projected antenna positions_.
if iono_rotate:
ns.pa0 << - Meq.ParAngle(xyz=ns.xyz_proj(stations[0]),radec=radec0);
ns.P0 << Jones.define_rotation_matrix(ns.pa0);
for p in stations:
# if ionosphere is stuck to the sky, rotate antenna coordinates by P0
if iono_rotate:
ns.xy_r(p) << Meq.MatrixMultiply(ns.P0,ns.xy1(p));
else:
# else create P (p/a rotation matrix)
ns.pa(p) << - Meq.ParAngle(xyz=ns.xyz_proj(p),radec=radec0);
ns.P(p) << Jones.define_rotation_matrix(ns.pa(p));
for src in source_list:
lm = src.direction.lm();
lm_sq = ns.lm_sq(src.name) << Meq.Sqr(lm);
# dxy is the relative X,Y coordinate of the piercing point for this source,
# relative to centre. In each direction it's to H*tg(alpha), where
# alpha is the direction of the source w.r.t. center (i.e., arccos l).
ns.dxy(src.name) << H*lm/Meq.Sqrt(1-lm_sq);
# now compute absolute piercings per source, per antenna
for p in Context.array.stations():
if iono_rotate:
ns.pxy(src.name,p) << ns.xy_r(p) + ns.dxy(src.name);
else:
ns.pxy(src.name,p) << ns.xy1(p) + Meq.MatrixMultiply(ns.P(p),ns.dxy(src.name));
return ns.pxy;
def compute_jones(self, nodes, stations=None, tags=None, label='', **kw):
stations = stations or Context.array.stations()
g_ampl_def = Meow.Parm(1)
g_phase_def = Meow.Parm(0)
nodes = Jones.gain_ap_matrix(nodes,
g_ampl_def,
g_phase_def,
tags=tags,
series=stations)
# make parmgroups for phases and gains
self.pg_phase = ParmGroup.ParmGroup(
label + "_phase",
nodes.search(tags="solvable phase"),
table_name="%s_phase.fmep" % label,
bookmark=4)
self.pg_ampl = ParmGroup.ParmGroup(label + "_ampl",
nodes.search(tags="solvable ampl"),
table_name="%s_ampl.fmep" % label,
bookmark=4)
# make solvejobs
ParmGroup.SolveJob("cal_" + label + "_phase",
"Calibrate %s phases" % label, self.pg_phase)
ParmGroup.SolveJob("cal_" + label + "_ampl",
"Calibrate %s amplitudes" % label, self.pg_ampl)
return nodes
def compute_jones (self,nodes,stations=None,tags=None,label='',inspectors=[],**kw):
stations = stations or Context.array.stations();
rot_def = Meow.Parm(0);
nr = Jones.rotation_matrix(nodes("R"),rot_def,tags=tags,series=stations);
ne = Jones.ellipticity_matrix(nodes("E"),rot_def,tags=tags,series=stations);
for p in stations:
nodes(p) << Meq.MatrixMultiply(nr(p),ne(p));
# make parmgroups for phases and gains
self.pg_rot = ParmGroup.ParmGroup(label+"_leakage",
nodes.search(tags="solvable"),
table_name="%s_leakage.mep"%label,bookmark=True);
# make solvejobs
ParmGroup.SolveJob("cal_"+label+"_leakage","Calibrate %s (leakage)"%label,self.pg_rot);
# make inspector for parameters
StdTrees.inspector(nodes('inspector'),self.pg_rot.nodes,bookmark=False);
inspectors.append(nodes('inspector'));
return nodes;
def compute_jones(self,
nodes,
stations=None,
tags=None,
label='',
inspectors=[],
**kw):
stations = stations or Context.array.stations()
rot_def = Meow.Parm(0)
nr = Jones.rotation_matrix(nodes("R"),
rot_def,
tags=tags,
series=stations)
ne = Jones.ellipticity_matrix(nodes("E"),
rot_def,
tags=tags,
series=stations)
for p in stations:
nodes(p) << Meq.MatrixMultiply(nr(p), ne(p))
# make parmgroups for phases and gains
self.pg_rot = ParmGroup.ParmGroup(label + "_leakage",
nodes.search(tags="solvable"),
table_name="%s_leakage.mep" % label,
bookmark=True)
# make solvejobs
ParmGroup.SolveJob("cal_" + label + "_leakage",
"Calibrate %s (leakage)" % label, self.pg_rot)
# make inspector for parameters
StdTrees.inspector(nodes('inspector'),
self.pg_rot.nodes,
bookmark=False)
inspectors.append(nodes('inspector'))
return nodes
def compute_jones (self,nodes,stations=None,tags=None,label='',**kw):
stations = stations or Context.array.stations();
g_ampl_def = Meow.Parm(1);
g_phase_def = Meow.Parm(0);
nodes = Jones.gain_ap_matrix(nodes,g_ampl_def,g_phase_def,tags=tags,series=stations);
# make parmgroups for phases and gains
self.pg_phase = ParmGroup.ParmGroup(label+"_phase",
nodes.search(tags="solvable phase"),
table_name="%s_phase.fmep"%label,bookmark=4);
self.pg_ampl = ParmGroup.ParmGroup(label+"_ampl",
nodes.search(tags="solvable ampl"),
table_name="%s_ampl.fmep"%label,bookmark=4);
# make solvejobs
ParmGroup.SolveJob("cal_"+label+"_phase","Calibrate %s phases"%label,self.pg_phase);
ParmGroup.SolveJob("cal_"+label+"_ampl","Calibrate %s amplitudes"%label,self.pg_ampl);
return nodes;