diff --git a/floenavi/polarstern.py b/floenavi/polarstern.py
index d04006e77d373e39775f071e96e748cbb6ccc0ba..332477dc43ee63f86747df83cba6fb6f1c9a197d 100644
--- a/floenavi/polarstern.py
+++ b/floenavi/polarstern.py
@@ -6,7 +6,8 @@
__author__ = "Stefan Hendricks"
import requests
-from datetime import datetime
+from dateutil.parser import parse as dtparse
+from datetime import datetime, timedelta
from pathlib import Path
from loguru import logger
import numpy as np
@@ -16,26 +17,28 @@ from icedrift import GeoReferenceStation
class PolarsternAWIDashboardPos(object):
- def __init__(self, begin_date=None, end_date=None, output="csv"):
+ def __init__(self, begin_date, end_date, time_pad_minutes=10):
"""
+ Get Polarstern position and heading from the Polarstern HYDRINS1 sensor
+ NOTE: The URL etc can be checked using the web interface at
+ https://dashboard.awi.de/data-xxl/index.html
+ :param begin_date: (datetime.datetime) Start of the requested temporal coverage
+ :param end_date: (datetime.datetime)Start of the requested temporal coverage
+ :param time_pad_minutes: (integer) The number of minutes the period will be extended
+ on both side to ensure the data coverage of Polarstern position and heading
+ data always fully comprised the requested data period
- :param begin_date:
- :param end_date:
- :param output:
"""
- # Save input arguments
- self.begin_date = begin_date
- self.end_date = end_date
- self.output = output
-
+ # Save input arguments and automatically extend data period
+ # using a short time window to ensure that there is always
+ # Polarstern data before the requested data period.
+ self.begin_date = begin_date - timedelta(minutes=time_pad_minutes)
+ self.end_date = end_date + timedelta(minutes=time_pad_minutes)
# --- Properties ---
# The format of the REST output.
- # NOTE: The (default) value is specified in the `output` keyword to this method
- self.format_dict = {"csv": "text/csv",
- "json": "application/json",
- "tab": "text/tab-separated-values"}
+ self.requested_format = "text/csv",
# Output format for the time stamp
# NOTE: Most sensors do not report faster than 1 second, therefore there is no need
@@ -45,36 +48,70 @@ class PolarsternAWIDashboardPos(object):
# The main URL to the dashboard REST interface
self.base_url = "https://dashboard.awi.de/data-xxl/rest/data"
- # A list of sensors
+ # Parameter to be pulled from the Polarstern Inertial Navigation Unit
+ # 1. Latitude
+ # 2. Longitude
+ # 3. True Heading
self.sensors = ["vessel:polarstern:hydrins_1:latitude$NRT",
"sensors=vessel:polarstern:hydrins_1:longitude$NRT",
"sensors=vessel:polarstern:hydrins_1:heading$NRT"]
- # Temporal resolution:
+ # Temporal resolution (full)
self.aggregate_value = "second"
- def save(self, filename=None):
- """
+ # Load the data
+ self.response = None
+ self.download()
- :param filename:
+ self._variables = {}
+ self.decode_response()
+
+ def download(self):
+ """
+ Pulls the data for the requested period from dashboard.awi.de
:return:
"""
# Construct the URL
url = self._construct_url()
- logger.debug("url=%s" % url)
+ logger.info("data request url: {}".format(url))
# Download the websites response
# TODO: Error management
r = requests.get(url)
# Post-process the content
- ascii_content = "\n".join(r.text.splitlines())
- if self.output == "csv":
- ascii_content = ascii_content.replace(";", ",")
+ self.response = "\n".join(r.text.splitlines())
+ self.response = self.response.replace(";", ",")
- # Write output file
- open(filename, 'w').write(ascii_content)
+ def decode_response(self):
+ """
+ Parses the response from the data service into arrays of time, longitude, latitude
+ and true heading.
+ :return:
+ """
+
+ # Init the variables
+ # NOTE: the first line is the header line and has to be ignored.
+ lines = self.response.split("\n")[1:]
+ n_lines = len(lines)
+ self._variables["time"] = np.full(n_lines, object)
+ for parameter_name in ["longitude", "latitude", "heading"]:
+ self._variables[parameter_name] = np.full(n_lines, np.nan)
+
+ for i, line in enumerate(lines):
+ string_array = line.split(",")
+ self._variables["time"][i] = dtparse(string_array[0])
+ self._variables["latitude"][i] = np.float(string_array[1])
+ self._variables["longitude"][i] = np.float(string_array[2])
+ self._variables["heading"][i] = np.float(string_array[3])
+
+ def save(self, filename):
+ """
+ :param filename:
+ :return:
+ """
+ raise NotImplementedError()
def _construct_url(self):
"""
@@ -89,18 +126,18 @@ class PolarsternAWIDashboardPos(object):
url += self.sensor_def
# add output format
- url += "&format=%s" % self.format_dict[self.output]
+ url += "&format=%s" % self.requested_format
# add temporal resolution
url += "&aggregate={}".format(self.aggregate_value)
# add begin date (optional)
if self.begin_date is not None:
- url += "&beginDate=%s" % self.begin_date.strftime(self.datetime_format)
+ url += "&beginDate={}".format(self.begin_date.strftime(self.datetime_format))
# add end date (optional)
if self.end_date is not None:
- url += "&endDate=%s" % self.end_date.strftime(self.datetime_format)
+ url += "&endDate={}".format(self.end_date.strftime(self.datetime_format))
return url
@@ -113,6 +150,26 @@ class PolarsternAWIDashboardPos(object):
sensor_def = "sensors="+"&".join(self.sensors)
return sensor_def
+ @property
+ def reference_station(self):
+ """
+ Return a icedrift.GeoReferenceStation instance
+ :return:
+ """
+ refstat = GeoReferenceStation(self.time, self.longitude, self.latitude, self.heading)
+ return refstat
+
+ def __getattr__(self, attr):
+ """
+ Modify the attribute getter to provide a shortcut to the data content
+ :param attr:
+ :return:
+ """
+ if attr in list(self._variables.keys()):
+ return self._variables[attr]
+ else:
+ raise AttributeError()
+
class PolarsternPOSDashboardData(object):
"""
@@ -180,5 +237,3 @@ class PolarsternPOSDashboardData(object):
data = GeoReferenceStation(content["time"], content["longitude"], content["latitude"], content["heading"])
return data
-
-