Dataset DOI: 10.5061/dryad.n8pk0p38q

Description of the data and file structure

PERSIANN-CCS-CDR Version 2.0 is regularly updated; therefore, this page serves as the DOI landing page for the dataset. A few sample files are provided here for reference.

PERSIANN-CCS-CDR V2.0 consists of 2 sub-products PERSIANN-CCS-CDR B1 from 1983 to present and PERSIANN-CCS-CDR CPC from March 2000 to present, both provide precipitation estimates at 0.04° spatial and 3-hourly temporal resolutions over the global domain of 60°S to 60°N.

To access and download the full dataset, please visit the CHRS Data Portal. (https://chrsdata.eng.uci.edu/)

The final PERSIANN-CCS-CDR rainfall data are accumulated (in mm) for
3hrly, 6hrly, daily, monthly, & yearly, provided in separate directories.

The files are named for the accumulation period and the
start time of the period.

PCCSCDRXXYYMMDDhh.bin.gz

XX -- will be 3h, 6h,1d, 1m, 1y

YYMMDD  -- year month day
YYMM for 1m data 
YYYY for 1y data 

hh -- will be the starting hour of the accumulation period. For example:
    PCCSCDR3h19010106.bin.gz
represents the mm accumulation over the 3 hour period on 2019 Jan 1st
from  06:00Z up through 08:59Z.

daily (1d) data do not have hh in the name and go from 00:00Z to 23:59Z of the given date.
monthly (1m) data are standardized to a 30day month.
yearly (1y) data are based on the accumulation for that calendar year.

All data are in flat binary files 4-byte float (float32) values in little-endian byte-order.

Area covered in .04 deg from 60N to 60S and 0 to 360 for
3000 rows x 9000 cols

Data are stored in the file in row-major orientation with the first 9000
values the N-most row centered at 59.98N  with longitude centers from
.02 to 359.98
and the last row (S-most row) centered at 59.98S 

The "Script.py" file can serve as an example on how to read the files.

just put the "Script.py" in "Example" folder, open CMD and run the following script:

cd C:\Users\User\Desktop\Examples #(replace this with directory of Examples folder on your system)
python .\Script.py

this script will read and plot the ".\PERSIANN-CCS-CDR CPC\PCCSCDR1d240101.bin.gz" file as an example. you can change the "PATH" variables to read different files.

The Script.py file can also be find bellow:

import numpy as np
def read_bin_file(filename, shape=(3000,9000)):
    if filename[-3:] == ".gz":
        import gzip
        with gzip.open(filename, "rb") as f:
            data = np.frombuffer(f.read(), dtype=np.float32)
    else:
        with open(filename, "rb") as f:
            data = np.fromfile(f, dtype=np.float32)  # Read as short integers 
    
    #data = data.byteswap().view(data.dtype.newbyteorder(">"))  # You might need to remove,or # change this line based on your system default endian settings
    data = data.reshape(shape)
    mask=data<0
    arr=np.full(data.shape,np.nan,dtype=np.float32)*np.nan
    arr[~mask]=data[~mask]
    return arr

# First exctract the Examples.zip files and then put the complete path name of #your desired file into variable "PATH"
PATH=r'.\PERSIANN-CCS-CDR CPC\PCCSCDR1d240101.bin.gz' # this path is probably #diffrent for your system
data=read_bin_file(PATH)
# to plot the data use this code:
import matplotlib.pyplot as plt
plt.figure()
plt.imshow(data,clim=(0,30))
cbar=plt.colorbar(fraction=.02)
cbar.set_label("mm")
xticks = [0, 4500,9000]
xlabels = ["0°", "180°", "360°",]
plt.xticks(xticks, xlabels)
yticks = [0, 1500, 3000]
ylabels = ["60°", "0°", "-60°",]
plt.yticks(yticks, ylabels)
plt.xlabel('Longitude')
plt.ylabel('Latitude')
plt.savefig('ex.png')
plt.show()

Files and variables

PERSIANN-CCS-CDR Version 2.0 is regularly updated; therefore, this page serves as the DOI landing page for the dataset.

To access and download the full dataset, please visit the CHRS Data Portal. (https://chrsdata.eng.uci.edu/)

For reference purposes, a limited set of sample files is provided in Examples.zip. This archive contains two subdirectories:

• PERSIANN-CCS-CDR B1 – sample files for the PERSIANN-CCS-CDR B1 subproduct
• PERSIANN-CCS-CDR CPC – sample files for the PERSIANN-CCS-CDR CPC subproduct

Within each subdirectory, example files are included for the following temporal resolutions: 3-hourly, 6-hourly, daily, monthly, and yearly, following the naming convention described above.

All files are provided in binary format. Instructions for properly reading and loading these files are also described above.

Access information

Publicly accessible locations of the data:

• https://chrsdata.eng.uci.edu/