雷达系列：两个国产雷达Python库读取对比
pycwr与pycinrad读取文件测试
前言
前段时间跟朋友聊了下两个国产雷达库的区别
想了想是不错的素材，遂稍作对比
pycwr和pycinrad都是用于读取和处理气象雷达数据的Python库。
它们的作用是帮助用户方便地读取、处理和分析气象雷达数据，包括反射率、速度和谱宽等信息。
对比这两个库可以让用户更好地了解它们的特点、功能和适用场景，从而更好地选择合适的库来处理气象雷达数据。
SC老格式
In :
from cinrad.io import CinradReader, StandardData
f = CinradReader('/home/mw/input/pycwr5461/Z_RADR_I_Z9240_20190703101340_O_DOR_SC_CAP.bin.bz2') #老版本数据,CC雷达最好加上radar_type
f.available_product(0)
Out:
['REF', 'VEL', 'SW', 'azimuth', 'RF']
In :
VEL = f.get_data(0, 230, 'REF')
VEL
Out:
In :
from pycwr.io import read_auto
PRD = read_auto("/home/mw/input/pycwr5461/Z_RADR_I_Z9240_20190703101340_O_DOR_SC_CAP.bin.bz2")
print(PRD.fields)
SAD标准格式
In :
g = StandardData('/home/mw/input/pycwr5461/Z_RADR_I_Z9898_20190828181529_O_DOR_SAD_CAP_FMT (1).bin.bz2')
g
Out:
<cinrad.io.level2.StandardData at 0x7f7f921358e0>
In :
g.available_product(0)
Out:
['TREF', 'REF', 'SQI', 'ZDR', 'RHO', 'PHI', 'KDP', 'SNRH']
In :
VEL1 = g.get_data(0, 230, 'REF')
VEL1
Out:
In :
PRD = read_auto("/home/mw/input/pycwr5461/Z_RADR_I_Z9898_20190828181529_O_DOR_SAD_CAP_FMT (1).bin.bz2")
print(PRD.fields)
相控阵2020格式
In :
from pycwr.io import read_PA
PRD = read_PA("/home/mw/input/pycwr5461/Z_RADR_I_ZGZ01_20200820220246_O_DOR_DXK_CAR.bin.bz2")
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-43-514a2fb40a87> in <module>
1 from pycwr.io import read_PA
----> 2 PRD = read_PA("/home/mw/input/pycwr5461/Z_RADR_I_ZGZ01_20200820220246_O_DOR_DXK_CAR.bin.bz2")
/opt/conda/lib/python3.9/site-packages/pycwr/io/__init__.py in read_PA(filename, station_lon, station_lat, station_alt)
68 :param station_alt:radar station altitude //units: meters
69 """
---> 70 return PAFile.PA2NRadar(PAFile.PABaseData(filename, station_lon, station_lat, station_alt)).ToPRD()
/opt/conda/lib/python3.9/site-packages/pycwr/io/PAFile.py in __init__(self, filename, station_lon, station_lat, station_alt)
29 self._check_standard_basedata()##确定文件是standard文件
30 self.header = self._parse_BaseDataHeader()
---> 31 self.radial = self._parse_radial()
32 self.nrays = len(self.radial)
33 # print(self.nrays)
/opt/conda/lib/python3.9/site-packages/pycwr/io/PAFile.py in _parse_radial(self)
75 self.MomentNum = RadialDict['MomentNumber']
76 self.LengthOfData = RadialDict['LengthOfData']
---> 77 RadialDict['fields'] = self._parse_radial_single()
78 if RadialDict["fields"]:
79 radial.append(RadialDict)
/opt/conda/lib/python3.9/site-packages/pycwr/io/PAFile.py in _parse_radial_single(self)
87 Momheader, _ = _unpack_from_buf(Mom_buf, 0, dtype_PA.RadialData())
88 Data_buf = self.fid.read(Momheader['Length'])
---> 89 assert (Momheader['BinLength'] == 1) | (Momheader['BinLength'] == 2), "Bin Length has problem!"
90 if Momheader['BinLength'] == 1:
91 dat_tmp = (np.frombuffer(Data_buf, dtype="u1", offset=0)).astype(int)
AssertionError: Bin Length has problem!
In :
from cinrad.io import PhasedArrayData
p = PhasedArrayData('/home/mw/input/pycwr5461/Z_RADR_I_ZGZ01_20200820220246_O_DOR_DXK_CAR.bin.bz2')
data = p.get_data(0, 100, 'REF')
data
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-42-544a32d2eceb> in <module>
1 from cinrad.io import PhasedArrayData
----> 2 p = PhasedArrayData('/home/mw/input/pycwr5461/Z_RADR_I_ZGZ01_20200820220246_O_DOR_DXK_CAR.bin.bz2')
3 data = p.get_data(0, 100, 'REF')
4 data
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in __init__(self, file)
884 except IndexError:
885 self.code = self.name = "None"
--> 886 self._d = data = np.frombuffer(f.read(), dtype=PA_radial)
887 self.stationlon = data["header"]["longitude"] * 360 / 65535
888 self.stationlat = data["header"]["latitude"] * 360 / 65535
ValueError: buffer size must be a multiple of element size
为什么都读取错误了呢
这里说明一下，由于相控阵的格式经历了多次改变。
此文件是2020年的相控阵文件，较老版本的pycwr应该是能读取的（因为文件就是来自pycwr的测试文件）
笔者测试过，pycinrad可以读取2022年的标准格式相控阵文件
目前pycwr对标的是2023年的格式。
SB格式
In :
from cinrad.io import CinradReader, StandardData
SB = CinradReader('/home/mw/input/pycwr5461/Z9396_BASE_SB_20180724_055400 (1).bin.bz2',radar_type='SB')
SB.available_product(0)
Out:['REF', 'VEL', 'SW', 'azimuth', 'RF']
In :
VEL = SB.get_data(0, 230, 'REF')
VEL
Out:
In :
from pycwr.io import read_auto
PRD = read_auto("/home/mw/input/pycwr5461/Z9396_BASE_SB_20180724_055400 (1).bin.bz2")
print(PRD.fields)
In :
from cinrad.io import CinradReader, StandardData
CC = CinradReader('/home/mw/input/pycwr5461/Z9396_BASE_SB_20180724_055400 (1).bin.bz2',radar_type='CC')
CC.available_product(0)
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in __init__(self, file, radar_type)
124 f.seek(0)
--> 125 self._SAB_reader(f, dtype="special")
126 except:
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in _SAB_reader(self, f, dtype)
153 _header_size = 132
--> 154 data = np.frombuffer(f.read(), dtype=radar_dtype)
155 start = datetime.datetime(1969, 12, 31)
ValueError: buffer size must be a multiple of element size
During handling of the above exception, another exception occurred:
NotImplementedError Traceback (most recent call last)
<ipython-input-55-39e883f9ddb5> in <module>
1 from cinrad.io import CinradReader, StandardData
----> 2 CC = CinradReader('/home/mw/input/pycwr5461/Z9396_BASE_SB_20180724_055400 (1).bin.bz2',radar_type='CC')
3 CC.available_product(0)
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in __init__(self, file, radar_type)
125 self._SAB_reader(f, dtype="special")
126 except:
--> 127 raise err
128 self._update_radar_info()
129 # TODO: Override information
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in __init__(self, file, radar_type)
112 try:
113 if self.radartype == "CC":
--> 114 self._CC_reader(f)
115 elif self.radartype in ["SC", "CD"]:
116 self._CD_reader(f)
/opt/conda/lib/python3.9/site-packages/cinrad/io/level2.py in _CC_reader(self, f)
216 scan_mode = header["ucScanMode"]
217 if scan_mode < 100:
--> 218 raise NotImplementedError("Only VPPI scan mode is supported")
219 stop_angle = scan_mode - 100
220 self.scantime = (
NotImplementedError: Only VPPI scan mode is supported
In :
PRD = read_auto("/home/mw/input/pycwr5461/2016070817 (1).48V.gz")
print(PRD.fields)
看来这种扫描模式的CC格式的雷达pycinrad不支持
小结
总的来说，pycwr的read_auto函数比较无脑，很适合萌新
但是pycinrad有官方qq群，有大佬解惑，
pycwr则是毫无交流的地方
对于其他不能读取的雷达格式，那就只能想办法找到说明书去写一个脚本读取了
文章来源于公众号：气python风雨
页:
[1]