mirror of
https://gitlab.science.ru.nl/mthesis-edeboone/m.internship-documentation.git
synced 2024-12-22 13:03:32 +01:00
figure: 4antennasetup + iter clock fix
Also showcases how to remove time offsets iteratively
This commit is contained in:
parent
48b2d6de0f
commit
5147ddfa1c
1 changed files with 228 additions and 0 deletions
228
figures/beacon/src/four_antenna_setup.py
Normal file
228
figures/beacon/src/four_antenna_setup.py
Normal file
|
|
@ -0,0 +1,228 @@
|
|||
#!/usr/bin/env python3
|
||||
|
||||
__doc__ = \
|
||||
"""
|
||||
Create a figure showing the timing and geometry of 3+1 antennas,
|
||||
and the triangles between them.
|
||||
The additional antenna is to show that baselines are shared between
|
||||
triangles.
|
||||
|
||||
In code (and on stdout), the antennas have time offsets which can be determined iteratively up to an overall offset.
|
||||
"""
|
||||
|
||||
import matplotlib.pyplot as plt
|
||||
import numpy as np
|
||||
from itertools import combinations
|
||||
|
||||
c_light = 3e8 # m/s
|
||||
|
||||
def distance(x1, x2):
|
||||
"""
|
||||
Calculate the Euclidean distance between two locations x1 and x2
|
||||
"""
|
||||
|
||||
assert type(x1) in [Antenna]
|
||||
x1 = np.array([x1.x, x1.y, x1.z])
|
||||
|
||||
assert type(x2) in [Antenna]
|
||||
x2 = np.array([x2.x, x2.y, x2.z])
|
||||
|
||||
return np.sqrt( np.sum( (x1-x2)**2 ) )
|
||||
|
||||
def phase_mod(phase, low=np.pi):
|
||||
"""
|
||||
Modulo phase such that it falls within the
|
||||
interval $[-low, 2\pi - low)$.
|
||||
"""
|
||||
return (phase + low) % (2*np.pi) - low
|
||||
|
||||
|
||||
class Antenna:
|
||||
"""
|
||||
Simple Antenna class
|
||||
"""
|
||||
def __init__(self,x=0,y=0,z=0,t0=0,name=""):
|
||||
self.x = x
|
||||
self.y = y
|
||||
self.z = z
|
||||
self.t0 = t0
|
||||
self.name = name
|
||||
|
||||
self.offsets = []
|
||||
|
||||
def __repr__(self):
|
||||
cls = self.__class__.__name__
|
||||
|
||||
return f'{cls}(x={self.x!r},y={self.y!r},z={self.z!r},t0={self.t0!r},name={self.name!r})'
|
||||
|
||||
def antenna_triangles(antennas):
|
||||
return combinations(antennas, 3)
|
||||
|
||||
def antenna_baselines(antennas):
|
||||
return combinations(antennas, 2)
|
||||
|
||||
def plot_four_antenna_geometry(tx, ants, extra_ant=None, ax=None, line_kwargs={}, scatter_kwargs={}, scatter_zorder=5):
|
||||
|
||||
default_line_kwargs = dict( color='grey', lw=3, alpha=0.7)
|
||||
default_scatter_kwargs = dict( color='grey', s=200)
|
||||
|
||||
if ax is None:
|
||||
ax = plt.gca()
|
||||
ax.set_aspect('equal')
|
||||
ax.set_xlabel("x")
|
||||
ax.set_ylabel("y")
|
||||
|
||||
line_kwargs = {**default_line_kwargs, **line_kwargs}
|
||||
scatter_kwargs = {**default_scatter_kwargs, **scatter_kwargs}
|
||||
|
||||
# Plot Antennas + Tx
|
||||
for i, ant in enumerate([tx] + ants + [extra_ant]):
|
||||
ax.scatter(ant.x, ant.y, zorder=scatter_zorder, **scatter_kwargs)
|
||||
ax.annotate(ant.name, (ant.x, ant.y), ha='center', va='center',zorder=scatter_zorder)
|
||||
|
||||
# Lines connecting Tx and ants
|
||||
tmp_line_kwargs = line_kwargs
|
||||
for ant in ants:
|
||||
ax.plot([tx.x, ant.x], [tx.y, ant.y], **tmp_line_kwargs)
|
||||
|
||||
# Lines due to all Antennas (including extra_ant)
|
||||
line_offset = 0.08*np.array([1,1])
|
||||
for i, ant_triangle in enumerate(antenna_triangles(ants + [extra_ant])):
|
||||
tmp_line_kwargs['color'] = None
|
||||
tmp_line_kwargs['linestyle'] = '--'
|
||||
tmp_line_kwargs['alpha'] = 0.4
|
||||
for j, ant in enumerate(antenna_baselines(ant_triangle)):
|
||||
a, b = ant[0], ant[1]
|
||||
if j == 1: # fix ordering
|
||||
a, b == b, a
|
||||
|
||||
dx, dy = (i-1)*line_offset
|
||||
|
||||
l = ax.plot([ a.x+dx, b.x+dx], [a.y+dy, b.y+dy], **tmp_line_kwargs)
|
||||
line_kwargs['color'] = l[0].get_color()
|
||||
|
||||
# Lines internal to ants triangle
|
||||
tmp_line_kwargs = line_kwargs
|
||||
tmp_line_kwargs['color'] = 'green'
|
||||
tmp_line_kwargs['alpha'] = 0.7
|
||||
for j, ant_pair in enumerate(combinations(ants,2)):
|
||||
a, b = ant_pair[0], ant_pair[1]
|
||||
if j == 1: # fix ordering
|
||||
a, b = b, a
|
||||
|
||||
ax.plot([ a.x, b.x], [a.y, b.y], **tmp_line_kwargs)
|
||||
|
||||
return ax
|
||||
|
||||
if __name__ == "__main__":
|
||||
use_phase = False
|
||||
correct_time = True
|
||||
|
||||
tx = Antenna(name="T", x=-8, y=2, t0=0)
|
||||
|
||||
ants = [
|
||||
Antenna(name='1', x=0, y= 0, t0=1 ),
|
||||
Antenna(name='2', x=2, y=-3, t0=4 ),
|
||||
Antenna(name='3', x=1, y= 3, t0=10 ),
|
||||
]
|
||||
|
||||
extra_ant = Antenna(name='4', x=4, y=-1, t0=-6)
|
||||
|
||||
|
||||
if False:#correct_time: # taken from the output of this script
|
||||
"""
|
||||
Antenna Triangle(1,2,3)
|
||||
j=0: 1,2
|
||||
j=1: 3,1
|
||||
j=2: 2,3
|
||||
sigmas: [-2.99999999 9. -6.00000001]
|
||||
sigmas sum: -8.881784197001252e-16
|
||||
(Antenna(x=0,y=0,z=0,t0=1,name='1'), Antenna(x=2,y=-3,z=0,t0=4,name='2'), Antenna(x=1,y=3,z=0,t0=10,name='3')) : [0. 2.99999999 9. ]
|
||||
Antenna Triangle(1,2,4)
|
||||
sigmas: [-2.99999999 -7.00000001 10. ]
|
||||
sigmas sum: 0.0
|
||||
(Antenna(x=0,y=0,z=0,t0=1,name='1'), Antenna(x=2,y=-3,z=0,t0=4,name='2'), Antenna(x=4,y=-1,z=0,t0=-6,name='4')) : [ 0. 2.99999999 -7.00000001]
|
||||
Antenna Triangle(1,3,4)
|
||||
sigmas: [-9. -7.00000001 16.00000001]
|
||||
sigmas sum: 0.0
|
||||
(Antenna(x=0,y=0,z=0,t0=1,name='1'), Antenna(x=1,y=3,z=0,t0=10,name='3'), Antenna(x=4,y=-1,z=0,t0=-6,name='4')) : [ 0. 9. -7.00000001]
|
||||
Antenna Triangle(2,3,4)
|
||||
sigmas: [ -6.00000001 -10. 16.00000001]
|
||||
sigmas sum: 0.0
|
||||
(Antenna(x=2,y=-3,z=0,t0=4,name='2'), Antenna(x=1,y=3,z=0,t0=10,name='3'), Antenna(x=4,y=-1,z=0,t0=-6,name='4')) : [ 0. 6.00000001 -10.
|
||||
"""
|
||||
print("Running with pre-corrected times")
|
||||
ants[1].t0 -= 2.99999999
|
||||
ants[2].t0 -= 9
|
||||
extra_ant.t0 -= -7
|
||||
|
||||
ax = plot_four_antenna_geometry(tx, ants, extra_ant=extra_ant)
|
||||
|
||||
fig = ax.get_figure()
|
||||
|
||||
### Lol, show my calculations are right
|
||||
for i, triangle in enumerate(antenna_triangles(ants + [extra_ant])):
|
||||
print("Antenna Triangle({},{},{})".format(*[ant.name for ant in triangle]))
|
||||
|
||||
sigma = np.zeros((3))
|
||||
for j, ant_pair in enumerate(antenna_baselines(triangle)):
|
||||
a, b = ant_pair[0], ant_pair[1]
|
||||
if j == 1: # fix ordering
|
||||
a, b = b, a
|
||||
|
||||
if i == 0: # print sigma pairing for first triangle
|
||||
print('j={}: {},{}'.format(j, a.name, b.name))
|
||||
|
||||
phys_Dt = (distance(tx, a) - distance(tx, b))/c_light
|
||||
meas_Dt = a.t0 - b.t0
|
||||
|
||||
if use_phase:
|
||||
f_beacon = 50e6 # Hz
|
||||
to_phase = lambda t: phase_mod(2*np.pi*f_beacon*t)
|
||||
|
||||
phys_Dt = to_phase(phys_Dt)
|
||||
meas_Dt = to_phase(meas_Dt)
|
||||
|
||||
sigma[j] = meas_Dt - phys_Dt
|
||||
|
||||
if False:
|
||||
print(
|
||||
"Dt'_{},{} = ".format(a.name, b.name)
|
||||
+ "{}".format(meas_Dt)
|
||||
+ " = {} - {}".format(a.t0, b.t0)
|
||||
)
|
||||
print(
|
||||
"Dt_{},{} = ".format(a.name, b.name)
|
||||
+ "{}".format(phys_Dt)
|
||||
+ " = {} - {}".format(distance(tx, a), distance(tx, b))
|
||||
)
|
||||
|
||||
print(
|
||||
"sigma_{},{} = ".format(a.name, b.name)
|
||||
+ "{}".format(sigma[j])
|
||||
)
|
||||
print("sigmas:", sigma)
|
||||
if use_phase:
|
||||
print("sigmas sum:", phase_mod(np.sum(sigma)))
|
||||
else:
|
||||
print("sigmas sum:", np.sum(sigma))
|
||||
|
||||
# Take the first antenna as reference
|
||||
ref_idx = 0
|
||||
ref_sigma = sigma[ref_idx]
|
||||
sigma = sigma - ref_sigma
|
||||
|
||||
ant_sigma = 1/3*np.array([0, sigma[1] + sigma[2], 2*sigma[1] - sigma[2]])
|
||||
|
||||
for i in [1,2]:
|
||||
triangle[i].offsets.append(-ant_sigma[i])
|
||||
if correct_time:
|
||||
triangle[i].backup_t0 = triangle[i].t0
|
||||
triangle[i].t0 += -ant_sigma[i]
|
||||
|
||||
if correct_time:
|
||||
print(ants + [extra_ant])
|
||||
for i, ant in enumerate(ants + [extra_ant]):
|
||||
print(i, ant.name, ant.offsets)
|
||||
|
||||
plt.show()
|
||||
Loading…
Reference in a new issue