Added galactic parallactic correction (621321d4) · Commits · INAF / DISCOS

Common/Servers/DewarPositioner/src/DewarPositioner/posgenerator.py

+51 −0

Original line number	Diff line number	Diff line
		@@ -52,12 +52,63 @@ class PosGenerator(object):
		logger.logNotice('%s: %s' %(raeson, ex.message))
		raise PosGeneratorError(raeson)

		def galactic_parallactic(self, source, siteInfo):
		"""Return the galactic parallactic angle"""
		try:
		latitude = siteInfo['latitude']
		except (KeyError, TypeError), ex:
		raise PosGeneratorError('cannot get the latitude: %s' %ex.message)
		except Exception, ex:
		raeson = 'unexpected exception getting the site latitude'
		logger.logNotice(raeson)
		raise PosGeneratorError(raeson)

		last_zerodiv_time = datetime.datetime.now()
		while True:
		try:
		t = getTimeStamp().value + 1106 # 100 ms in the future
		coordinates = source.getApparentCoordinates(t) # Values in radians
		az, el, ra, dec = coordinates[:4]
		p = PosGenerator.getParallacticAngle(latitude, az, el)
		pg = PosGenerator.getGalacticParallacticAngle(ra, dec)
		yield p + pg
		last_zerodiv_time = datetime.datetime.now()
		except ZeroDivisionError:
		logger.logWarning('zero division error computing the galactic parallactic angle')
		zerodiv_time = datetime.datetime.now() - last_zerodiv_time
		if zerodiv_time.seconds >= self.zdtimeout:
		raeson = 'zero division for more than %ds' %self.zdtimeout
		logger.logError(raeson)
		raise PosGeneratorError(raeson)
		else:
		time.sleep(0.5)
		continue
		except GeneratorExit: # Required in Python 2.5:
		# http://www.algorithm.co.il/blogs/programming/generatorexit-another-reason-to-upgrade-to-python-2-6/
		raise
		except Exception, ex:
		raeson = 'cannot get the %s (az, el) values' %source._get_name()
		logger.logNotice('%s: %s' %(raeson, ex.message))
		raise PosGeneratorError(raeson)

		@staticmethod
		def getParallacticAngle(latitude, az, el):
		"""Arguments in radians"""
		p = atan2(-sin(az), tan(latitude)cos(el) - sin(el)cos(az))
		return degrees(p)

		@staticmethod
		def getGalacticParallacticAngle(ra, dec):
		"""Arguments in radians"""
		# North celestial pole coordinates in equatorial celestial frame (j200)
		# ncp = ('12 51 26.28', '27 07 41.7')
		# ra0 = ephem.hours(ncp[0])
		# dec0 = ephem.degrees(ncp[1])
		ra0 = 3.3660332687500043
		dec0 = 0.47347728280415174
		gp = atan2(sin(ra-ra0), cos(dec)tan(dec0) - sin(dec)cos(ra-ra0))
		return degrees(gp)


		class PosGeneratorError(Exception):
		pass

Common/Servers/DewarPositioner/test/pyunit/posgen/test_galactic_parallactic.py

0 → 100644

+53 −0

Original line number	Diff line number	Diff line
		import unittest2
		import mocker
		from math import sin, cos, tan, atan, radians, degrees, pi, atan2
		from DewarPositioner.posgenerator import PosGenerator, PosGeneratorError


		class PosGeneratorGalacticParallacticTest(unittest2.TestCase):

		def setUp(self):
		self.m = mocker.Mocker()
		self.source = self.m.mock()
		self.posgen = PosGenerator(zdtimeout=2)

		def tearDown(self):
		self.m.restore()
		self.m.verify()

		def test_ra_dec_values(self):
		"""Raise a PosGeneratorError if cannot get the (ra, dec) values"""
		source = self.m.mock()
		mocker.expect(source.getApparentCoordinates(mocker.ANY)).result((None, None))
		mocker.expect(source._get_name()).result('mocker')
		self.m.replay()
		gen = self.posgen.galactic_parallactic(source, siteInfo={'latitude': 39})
		self.assertRaises(PosGeneratorError, gen.next)

		def test_right_behavior(self):
		"""Generate 3 positions and do not stop in case of isolated zero div"""
		azimuths = (45, 45, 90, 45)
		elevations = (45, 45, 0, 45) # The value 0 will cause a zero division
		ra, dec = (2.0, 0.5)
		ra0 = 3.3660332687500043 # Radians
		dec0 = 0.47347728280415174 # Radians
		latitude = 0
		source = self.m.mock()
		for (az, el) in zip(azimuths, elevations):
		mocker.expect(
		source.getApparentCoordinates(mocker.ANY)
		).result((radians(az), radians(el), ra, dec) + (None,)*3)
		self.m.count(1)
		self.m.replay()
		gen = self.posgen.galactic_parallactic(source, siteInfo={'latitude': latitude})
		latitude = radians(latitude)
		for azd, eld in zip(azimuths, elevations):
		az = radians(azd)
		el = radians(eld)
		p = atan2(-sin(az), (tan(latitude)cos(el) - sin(el)cos(az)))
		gp = atan2(sin(ra-ra0), cos(dec)tan(dec0) - sin(dec)cos(ra-ra0))
		self.assertAlmostEqual(degrees(p + gp), gen.next(), delta=0.01)


		if __name__ == '__main__':
		unittest2.main()

SRT/Configuration/CDB/alma/DataBlock/DewarPositioner/KKG/BSC/UpdatingPosition/UpdatingPosition.xml

+3 −3

Original line number	Diff line number	Diff line
		@@ -54,19 +54,19 @@
		<UpdatingRecord>
		<axisCode>MNG_GAL_LON</axisCode>
		<initialPosition>-19.2</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>MNG_GAL_LAT</axisCode>
		<initialPosition>-49.2</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>JUST_FOR_TEST</axisCode>
		<initialPosition>-9.0</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		</DewarPositionerUpdatingTable>

SRT/Configuration/CDB/alma/DataBlock/DewarPositioner/KKG/BSC_OPT/UpdatingPosition/UpdatingPosition.xml

+3 −3

Original line number	Diff line number	Diff line
		@@ -54,19 +54,19 @@
		<UpdatingRecord>
		<axisCode>MNG_GAL_LON</axisCode>
		<initialPosition>-19.2</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>MNG_GAL_LAT</axisCode>
		<initialPosition>-49.2</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>JUST_FOR_TEST</axisCode>
		<initialPosition>-9.0</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		</DewarPositionerUpdatingTable>

SRT/Configuration/CDB/alma/DataBlock/DewarPositioner/KKG/CUSTOM/UpdatingPosition/UpdatingPosition.xml

+3 −3

Original line number	Diff line number	Diff line
		@@ -54,19 +54,19 @@
		<UpdatingRecord>
		<axisCode>MNG_GAL_LON</axisCode>
		<initialPosition>0.0</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>MNG_GAL_LAT</axisCode>
		<initialPosition>0.0</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		<UpdatingRecord>
		<axisCode>JUST_FOR_TEST</axisCode>
		<initialPosition>0.0</initialPosition>
		<functionName>gpa</functionName>
		<functionName>galactic_parallactic(</functionName>
		</UpdatingRecord>

		</DewarPositionerUpdatingTable>