README FOR THE X-BAND RADAR DATA

CHUVA/GoAmazon/ACRIDICON Manaus / Manacapuru Experiment

Radar geographical info:

height = 62.8 m
lat = -3.21304
lon = -60.598332

Level 0 info:

Level 0 and level 1 data  are in HDF5 format. There are up to 8 variables in each level 0 file:

- Uncorrected reflectivity (no clutter filter) (UZ)
- Corrected reflectivity (w/ clutter filter) (Z)
- Velocity (V)
- Spectral Width (W)
- Differential Reflectivity (ZDR)
- Differential propagation phase (PhiDP) 
- Specific differential phase (KDP)
- Co-polar correlation coefficient (RhoHV)

Detailed info about the scan parameters are found within each file. 

IMPORTANT NOTES:

- Some files are missing the polarization information due to radar malfunction. These files have only the first 4 variables (UZ, Z, V, and W). Check no_pol_list.txt for details.

- Some files have up to 3 elevations with no data. Check blank_elevations_list.txt for details.

Level 1 info:

There are 2 variables in each file:

- Corrected reflectivity (w/ clutter filter) (Z)
- Differential Reflectivity (ZDR)

both corrected for attenuation using the ZPHI method (see atten_corr.pdf and attenuation_correction_parameters.txt for details)

- Some files have up to 3 elevations with no data. Check blank_elevations_list.txt for details.


Level 2 info:

Level 2 data are corrected reflectivity (i.e.: w/ clutter filter) CAPPIs from 2 up to 16 km, one CAPPI each 1 km. The data are 4 bytes (floating point), 1000 x 1000 x 15, i.e., 15 blocks (one for each level) of 1000 x 1000 grid points. The first matrix is the 2 km CAPPI, then the 3 km, up to the 16 km CAPPI.

Undefined values are signed with:

BADVAL: 0x20000 (decimal: 131072)
NOECHO: BADVAL - 5 (decimal: 131067)

BADVAL means that the cell lies outside data range.
NOECHO means that there is no echo in the raw data.

In some rare cases values between 131067 and 131072 might appear, meaning that H or V data were not found. We recommend to replace any value over 131067 with BADVAL (131072).

The horizontal resolution is 200 m, 100 km radius.

For more info contact

thiago.biscaro@cptec.inpe.br

Updated: 09.Jul.2014