EOFError: Unexpected EOF detected while reading RADOLAN header

Openradar
,
1

Hi all,

I am trying to read radolan file which is in ASCII format. I am using following versions.

python=3.9.13
wradlib version=1.16.2

import wradlib as wrl
import xarray as xr
import matplotlib.pyplot as pl
import warnings

warnings.filterwarnings("ignore")
try:
    get_ipython().magic("matplotlib inline")
except:
    pl.ion()
import numpy as np

src_path = "D:/Sandeep/Thesis/Data/Extracted/"

data, metadata = wrl.io.read_radolan_composite(src_path+"RW-20050601.tar.gz")

Error:

---------------------------------------------------------------------------
EOFError                                  Traceback (most recent call last)
Input In [8], in <cell line: 1>()
----> 1 data, metadata = wrl.io.read_radolan_composite(src_path+"RW-20050601.tar.gz")

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:763, in read_radolan_composite(f, missing, loaddata, fillmissing)
    760 NODATA = missing
    762 # get _radolan_file class
--> 763 with _radolan_file(
    764     f, fillmissing=fillmissing, copy=True, ancillary=False
    765 ) as radfile:
    767     attrs = radfile.attrs
    769     if not loaddata:

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:1016, in _radolan_file.__init__(self, filename, fillmissing, copy, ancillary)
   1014 self._fill = fillmissing
   1015 self._copy = copy
-> 1016 self._ancillary = self._get_ancillary(requested=ancillary)

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:1190, in _radolan_file._get_ancillary(self, requested)
   1189 def _get_ancillary(self, requested=True):
-> 1190     if self.product in ["PG", "PC"]:
   1191         anc = ("nodatamask",)
   1192     elif self.product in ["RX", "EX", "WX"]:

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:1029, in _radolan_file.product(self)
   1026 @property
   1027 def product(self):
   1028     if self._product is None:
-> 1029         self._product = self.attrs["producttype"]
   1030     return self._product

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:1023, in _radolan_file.attrs(self)
   1020 if self._attrs is None:
   1021     # move file pointer to start
   1022     self.fp.seek(0)
-> 1023     self._attrs = self._read_attrs()
   1024 return self._attrs

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:1062, in _radolan_file._read_attrs(self)
   1061 def _read_attrs(self):
-> 1062     header = read_radolan_header(self.fp)
   1063     return parse_dwd_composite_header(header)

File ~\anaconda3\lib\site-packages\wradlib\io\radolan.py:690, in read_radolan_header(fid)
    688 mychar = fid.read(1)
    689 if not mychar:
--> 690     raise EOFError("Unexpected EOF detected while reading " "RADOLAN header")
    691 if mychar == b"\x03":
    692     break

EOFError: Unexpected EOF detected while reading RADOLAN header
2

Hi Sandeep,

wradlib is only able to read the binary RADOLAN data files. wradlib cannot read the ASCII RADOLAN data files.

I’m sorry to not have a better answer for you. My suggestion would be to read the data using numpy/pandas CSV readers. If you get a working prototype, we might have the chance to put that into wradlib. I encourage you to open a feature request issue at the wradlib GitHub issue tracker.

3

Hi Kai,

Now I understand ASCII radolan data files are not readable using wradlib library. I have to consider using numpy or pandas for reading the data.

So here my goal is to analyse different precipitation types from 2005 - 2021 in the state of Brandenburg, Germany. If I can read the files using pandas, is it possible to achieve my goal without using wradlib or radproc libraries for ASCII radolan data files?

Thanks in advance!
Sandeep

4

Hi Sandeep,

If you can read the data using numpy/padas or other means, it depends on what your processing needs are. You might not need wradlib then. But nevertheless, it might still be a good idea to equip wradlib with that capability. So my suggestion would be: Please open a feature request here. I’ll check how to read that data and put it into wradlib. Deal?

5

Hi Kai,

I just posted the issue on github. Thank you for all the timely replies from your side.

Thanks
Sandeep

6

Here the Issue and Pullrequest for reference. Let’s iterate over there and present solution here, when finalized.

Issue: Reading ASCII radolan data files using wradlib · Issue #593 · wradlib/wradlib · GitHub
PullRequest: WIP: ENH: read RADOLAN ascii format by kmuehlbauer · Pull Request #594 · wradlib/wradlib · GitHub

7

With wradlib version 1.17.0 the capability to read RADOLAN ASCII GIS files is implemented. Have a look at the documentation RADOLAN data formats — wradlib.