implementation of thermal noise removal

LT1AB
Vincent Schut 2020-10-07 10:54:57 +02:00 committed by piyushrpt
parent 9bfa2dd6db
commit b1bbf0f10f
1 changed files with 127 additions and 76 deletions

View File

@ -31,6 +31,7 @@
import isce
import xml.etree.ElementTree as ElementTree
from collections import defaultdict
import datetime
import isceobj
from isceobj.Util import Poly1D, Poly2D
@ -121,8 +122,9 @@ class Sentinel1(Component):
self.noiseCorrectionApplied = False
self.betaLUT = None
self.noiseLUT = None
self.gr2srLUT = None
self.noiseRangeLUT = None
self.noiseAzimuthLUT = None
self._xml_root=None
@ -637,24 +639,19 @@ class Sentinel1(Component):
Extract Noise look up table from calibration file.
'''
if not self.noiseCorrectionApplied:
self.noiseLUT = 0.0
return
from scipy.interpolate import RectBivariateSpline
from scipy.interpolate import interp1d, InterpolatedUnivariateSpline
if self.noiseXml is None:
raise Exception('No calibration file provided')
if self.noiseXml.startswith('/vsizip'):
if '.zip' in self.noiseXml:
import zipfile
parts = self.noiseXml.split(os.path.sep)
zipname = os.path.join(*(parts[2:-4]))
fname = os.path.join(*(parts[-4:]))
parts = self.noiseXml.split('.zip/')
zipname = parts[0] + '.zip'
fname = parts[1]
try:
with zipfile.ZipFile(zipname, 'r'):
with zipfile.ZipFile(zipname, 'r') as zf:
xmlstr = zf.read(fname)
except:
raise Exception('Could not read noise file: {0}'.format(self.calibrationXml))
@ -665,33 +662,78 @@ class Sentinel1(Component):
except:
raise Exception('Could not read noise file: {0}'.format(self.calibrationXml))
if float(self.IPFversion) < 2.90:
noise_range_vector_name = "noiseVectorList"
noise_range_lut_name = "noiseLut"
has_azimuth_noise_vectors = False
self.noiseAzimuthLUT = None
else:
noise_range_vector_name = "noiseRangeVectorList"
noise_range_lut_name = "noiseRangeLut"
has_azimuth_noise_vectors = True
print("Extracting noise LUT's...")
_xml_root = ElementTree.fromstring(xmlstr)
node = _xml_root.find('noiseVectorList')
num = int(node.attrib['count'])
node = _xml_root.find(noise_range_vector_name)
num_vectors = int(node.attrib['count'])
lines = []
pixels = []
data = None
print("File contains {} range noise vectors.".format(num_vectors))
full_samples_range = np.arange(self.product.numberOfSamples)
noise_range_lut_indices = np.zeros((num_vectors,))
noise_range_lut_values = np.zeros((num_vectors, self.product.numberOfSamples))
for ii, child in enumerate(node.getchildren()):
print("Processing range noise vector {}/{}".format(ii + 1, num_vectors))
pixnode = child.find('pixel')
nump = int(pixnode.attrib['count'])
if ii==0:
data = np.zeros((num,nump))
pixels = [float(x) for x in pixnode.text.split()]
sample_pixels = [float(x) for x in pixnode.text.split()]
signode = child.find(noise_range_lut_name)
vector = np.asarray([float(x) for x in signode.text.split()])
vector_interpolator = InterpolatedUnivariateSpline(sample_pixels, vector, k=1)
vector_interpolated = vector_interpolator(full_samples_range)
lines.append( int(child.find('line').text))
signode = child.find('noiseLut')
data[ii,:] = [float(x) for x in signode.text.split()]
noise_range_lut_indices[ii] = int(child.find('line').text)
noise_range_lut_values[ii] = vector_interpolated
fp.close()
lines = np.array(lines)
pixels = np.array(pixels)
self.noiseRangeLUT = interp1d(noise_range_lut_indices, noise_range_lut_values, kind='linear', axis=0, fill_value="extrapolate")
if has_azimuth_noise_vectors:
node = _xml_root.find("noiseAzimuthVectorList")
num_vectors = int(node.attrib['count'])
print("File contains {} azimuth noise blocks.".format(num_vectors))
noise_azimuth_lut_indices = defaultdict(list)
noise_azimuth_lut_values = defaultdict(list)
for block_i, child in enumerate(node.getchildren()):
print("Processing azimuth noise vector {}/{}".format(block_i + 1, num_vectors))
linenode = child.find('line')
signode = child.find("noiseAzimuthLut")
block_range_start = int(child.find('firstRangeSample').text)
block_range_end = int(child.find('lastRangeSample').text)
block_azimuth_start = int(child.find('firstAzimuthLine').text)
block_azimuth_end = int(child.find('lastAzimuthLine').text)
block_line_index = [float(x) for x in linenode.text.split()]
block_vector = [float(x) for x in signode.text.split()]
block_line_range = np.arange(block_azimuth_start, block_azimuth_end + 1)
block_vector_interpolator = InterpolatedUnivariateSpline(block_line_index, block_vector, k=1)
for line in block_line_range:
noise_azimuth_lut_indices[line].extend([block_range_start, block_range_end])
noise_azimuth_lut_values[line].extend([block_vector_interpolator(line)] * 2)
self.noiseAzimuthLUT = (noise_azimuth_lut_indices, noise_azimuth_lut_values)
else:
print("File contains no azimuth noise blocks.")
self.noiseLUT = RectBivariateSpline(lines,pixels, data, kx=1,ky=1)
if False:
import matplotlib.pyplot as plt
@ -711,7 +753,7 @@ class Sentinel1(Component):
except ImportError:
raise Exception('GDAL python bindings not found. Need this for RSAT2/ TandemX / Sentinel1.')
from scipy.interpolate import interp2d
from scipy.interpolate import interp1d
if parse:
self.parse()
@ -744,6 +786,9 @@ class Sentinel1(Component):
fid = open(self.output, 'wb')
pix = np.arange(self.product.numberOfSamples)
if self.noiseAzimuthLUT is not None:
noise_azimuth_lut_indices, noise_azimuth_lut_values = self.noiseAzimuthLUT
for ii in range(self.product.numberOfLines//100 + 1):
ymin = int(ii*100)
ymax = int(np.clip(ymin+100,0, self.product.numberOfLines))
@ -752,19 +797,25 @@ class Sentinel1(Component):
break
lin = np.arange(ymin,ymax)
####Read in one line of data
####Read in one block of data
data = 1.0 * band.ReadAsArray(0, ymin, self.product.numberOfSamples, ymax-ymin)
lut = self.betaLUT(lin,pix,grid=True)
if noiseFactor != 0.0:
noise = self.noiseLUT(lin,pix,grid=True)
noise = self.noiseRangeLUT(lin)
if self.noiseAzimuthLUT is not None:
block_azimuth_noise = np.zeros_like(noise)
for l_i, line in enumerate(lin):
interpolator = interp1d(noise_azimuth_lut_indices[line], noise_azimuth_lut_values[line], kind='previous', fill_value="extrapolate")
block_azimuth_noise[l_i] = interpolator(np.arange(self.product.numberOfSamples))
noise *= block_azimuth_noise
else:
noise = 0.0
#outdata = data
outdata = data*data/(lut*lut) + noiseFactor * noise/(lut*lut)
outdata = np.clip(data*data/(lut*lut) + noiseFactor * noise/(lut*lut), 0, None)
#outdata = 10 * np.log10(outdata)
outdata.astype(np.float32).tofile(fid)