Comparison_WERA-ADCP_Sept2013.rst 5.16 KB

Comparison WERA and ADCP radial velocities September 2013

Matlab script used to do the analysis is RadialVeloCompa_Sept2013_HFR_ADCP_WERA_ADCPcorrected_v2.m

Steps of the algorithm:

1- we choose a site to analyze, either PAO (site 1) or PAB (site 2)


location of HFRs domain in the St Lawrence estuary

2- we load the bathymetry and the HFR sites'coordinates

3- we specify if we use the "old" or "new" calibrations. Usually "New".

4- we load IML-4 ADCP data (2013) and gps data

5- we make a list of all the HFR files available for the site of interest.

6- we analyze the ADCP data (bin 2 only to get near-surface data):

  • We look for the indices of the ADCP time vector corresponding to the time period of interest (here 01 to 30 September 2013).
  • For each index, we look for the ADCP position (xadcp,yadcp)(via the gps coordinates).
  • We then look for the positions 15min before and 15min after.
  • We estimate the mean drift of the ADCP within these 30 minutes (Umean_adcp_u, Umean_adcp_v and U_mean_adcp (total)).
  • We find the radial orientation at the ADCP position given by xadcp,yadcp: azimuth in degrees from HFR site to adcp position
  • We project U_mean_adcp onto the radial direction to get the radial current components (ur_adcp_proj, vr_adcp_proj).
  • We store all the meaningful parameters into a structure named adcp.

7- We analyze the HFR data:

  • We look for the indices of the HFR time vector corresponding to the time period of interest (here 01 to 30 September 2013)
  • For each index, we load the corresponding HFR file (i.e. 20132440000_pao.mat). Each file contains a grid (X,Y) with radial currents at each grid point (Ur), a corresponding time vector (t) and the angle and distance from the site (theta,r).

Hourly radial currents from ADCP bin 2 and HFR WERA at PAO - September 2013 - superimposed are the 48-h averages

  • We then look for the HFR grid point nearest the ADCP position at the time of interest.

example of grid coverage

  • We find the HFR Radial velocity at this position and project it onto zonal and meridional components.
  • We store all the meaningful parameters into a structure named radar.

This analysis allows us to compare radial velocity components from each HFR site with the ADCP components.

HFR direction

To verify that the HFR looks in the right direction:

# For each time step of the time period of interest, we compute the distance from the HFR site to each grid point. We select the grid points that are at the same range from the HFR site than the grid point closest to the ADCP.


# For each of these grid point (in cyan in the figure), we compute the azimuth the the site coordinates and we extract the radial velocity (total) and its components (zonal and meridional).

#We store all the meaningful parameters into a structure named range.

Results from the whole analysis are stored, for example, under: /run/media/bandma01/SeagateWireless/MEOPAR/Matlab/Analysis/Radial_Comparison/201309/ADCP-PAO/ADCP_PAO_version5adcpCorrected_newcalibrations_v2.mat


generated with PlotRadialVeloCompa_Sept2013_HFR_ADCP_WERA_v2.m


Comparison of radial velocities from ADCP bin 2 and HFR WERA at PAO site September 2013



generated with PlotRadialVeloCompa_Sept2013_HFR_ADCP_WERA_v2.m


RMS diff and correlation from radial velocities compared betwen 1/ ADCP bin 2 and HFR WERA at PAO site September 2013 (HFR grid point closest to ADCP location) and 2/ using model data at ADCP location and at HFR grid point closest to ADCP