From bd50af98b62628067e6a0b670c080944cbcc7004 Mon Sep 17 00:00:00 2001
From: XANTRONIX Industrial <xan@xantronix.com>
Date: Sun, 23 Feb 2025 20:00:01 -0500
Subject: [PATCH] Initial implementation of IGRA data parser
---
lib/xmet/igra.py | 149 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 149 insertions(+)
create mode 100644 lib/xmet/igra.py
diff --git a/lib/xmet/igra.py b/lib/xmet/igra.py
new file mode 100644
index 0000000..6e9e531
--- /dev/null
+++ b/lib/xmet/igra.py
@@ -0,0 +1,149 @@
+import io
+import re
+import datetime
+import shapely
+
+from xmet.coord import COORD_SYSTEM
+from xmet.sounding import Sounding, SoundingSample
+
+RE_HEADER = re.compile(r'''
+ ^ (?P<headrec>\#)
+ (?P<id>[A-Z0-9]{11})
+ [ ] (?P<year>\d{4})
+ [ ] (?P<month>\d{2})
+ [ ] (?P<day>\d{2})
+ [ ] (?P<hour>\d{2})
+ [ ] (?P<relhour>\d{2}) (?P<relmin>\d{2})
+ [ ] (?P<numlev>[0-9\ ]{4})
+ [ ] (?P<p_src>.{8})
+ [ ] (?P<np_src>.{8})
+ [ ] (?P<lat>[0-9 ]{7})
+ [ ] (?P<lon>[0-9 ]{8})
+ $
+''', re.X)
+
+RE_SAMPLE = re.compile(r'''
+ ^ (?P<lvltyp1>\d)
+ (?P<lvltyp2>\d)
+ [ ] (?P<etime>[0-9 \-]{5})
+ (?P<press>[0-9 \-]{7})
+ (?P<pflag>[AB ])
+ (?P<gph>[0-9 \-]{5})
+ (?P<zflag>[AB ])
+ (?P<temp>[0-9 \-]{5})
+ (?P<tflag>[AB ])
+ (?P<rh>[0-9 \-]{5})
+ [ ] (?P<dpdp>[0-9 \-]{5})
+ [ ] (?P<wdir>[0-9 \-]{5})
+ [ ] (?P<wspd>[0-9 \-]{5})
+''', re.X)
+
+def etime_to_seconds(etime: str) -> int:
+ if etime == '-8888' or etime == '-9999':
+ return
+
+ return 60 * int(etime[0:2]) + int(etime[2:])
+
+def parse_num(num: str, scale: float) -> float:
+ if num == '-8888' or num == '-9999':
+ return
+
+ return int(num) * scale
+
+class IGRAReaderException(Exception):
+ ...
+
+class IGRAReader():
+ def __init__(self, fh: io.TextIOBase):
+ self.fh = fh
+
+ def read_sample(self) -> SoundingSample:
+ line = self.fh.readline()
+
+ if line == '':
+ return
+
+ match = RE_SAMPLE.match(line)
+
+ if match is None:
+ raise IGRAReaderException(f"Invalid sample line {line}")
+
+ print(f"Got etime '{match['etime']}'")
+ print(f"Got press '{match['press']}'")
+ print(f"Got pflag '{match['pflag']}'")
+ print(f"Got gph '{match['gph']}'")
+ print(f"Got zflag '{match['zflag']}'")
+ print(f"Got temp '{match['temp']}'")
+ print(f"Got rh '{match['rh']}'")
+
+ sample = SoundingSample()
+ sample.elapsed = etime_to_seconds(match['etime'])
+ sample.pressure = parse_num(match['press'], 0.01)
+ sample.pressure_qa = match['pflag']
+ sample.height = parse_num(match['gph'], 1.0)
+ sample.height_qa = match['zflag']
+ sample.temp = parse_num(match['temp'], 0.1)
+ sample.temp_qa = match['tflag']
+ sample.humidity = parse_num(match['rh'], 0.1)
+ sample.dewpoint = parse_num(match['dpdp'], 0.1)
+ sample.wind_dir = parse_num(match['wdir'], 1.0)
+ sample.wind_speed = parse_num(match['wspd'], 0.1)
+
+ return sample
+
+ def read(self) -> Sounding:
+ line = self.fh.readline()
+
+ if line == '':
+ return
+
+ line = line.rstrip()
+
+ match = RE_HEADER.match(line)
+
+ if match is None:
+ raise IGRAReaderException(f"Invalid record line {line}")
+
+ sounding = Sounding()
+ sounding.station = match['id']
+
+ date = datetime.datetime(
+ year = int(match['year']),
+ month = int(match['month']),
+ day = int(match['day'])
+ )
+
+ timestamp = date.astimezone(datetime.UTC)
+ timestamp_release = date.astimezone(datetime.UTC)
+
+ if match['hour'] != '99':
+ timestamp += datetime.timedelta(hours=int(match['hour']))
+
+ timestamp_release += datetime.timedelta(hours=int(match['relhour']))
+
+ if match['relmin'] != '99':
+ timestamp_release += datetime.timedelta(minutes=int(match['relmin']))
+
+ lat = int(match['lat']) / 1000.0
+ lon = int(match['lon']) / 1000.0
+
+ sounding.timestamp_observed = timestamp
+ sounding.timestamp_released = timestamp_release
+ sounding.data_source_pressure = match['p_src']
+ sounding.data_source_other = match['np_src']
+ sounding.coord = shapely.Point(lon, lat, COORD_SYSTEM)
+ sounding.samples = list()
+
+ count = int(match['numlev'])
+
+ while count > 0:
+ sample = self.read_sample()
+
+ if sample is None:
+ break
+
+ sounding.samples.append(sample)
+
+ count -= 1
+
+ return sounding