RDSS/editor

(http://olympic.atmos.colostate.edu/rdss.html)


3. editor or RDSS

Format: UF

This is the primary editing, viewing, and (some) date analysis tool for radar data. To start, just type "editor" and enter. A graphics window will come up by clicking the mouse. Then follow this sample start of an editor session to get started:

ats% editor
Opened device type x11, Wsta 0x19a000
Got 128 colors at 0

                FOF radar data editor (Unix)

        -1 = EXIT 
         0 = Continue 
         1 = Save menus, prompts, and user responses
Select Option 

(NOTE:  A Return is defaulted to a "0" response).

The Editor requires its own reformatted file.  To create
such a file from tape or from files produced by Todisk or
Toindex, you must exercise the TAPE/DISK INPUT option.

To access an existing Editor file (file with .red suffix)
to edit or display data, you must first exercise the ACCESS
AN EDITOR FILE option before selecting EDITING AND DISPLAY.

To create a Universal Format output tape from a disk file,
you must first ACCESS AN EDITOR FILE before exercising the
TAPE/DISK OUTPUT option.



        0 = EXIT this program
        1 = Tape/disk input
        2 = Access an editor file
        3 = Editing and display
        4 = Tape/disk output
        5 = On line documentation

Select next course of action: 1
Enter file name: MCTEX_951117_0508.uf

Type the editor file name without .red suffix ==> MCTEX_951117_0508
Hit  to continue

17-NOV-95 05:08:34 AZ:269.8 EL:  0.7 FX:  0.7 PPI FI: 1 RE:    1 LE:3664 SW:  1
MCTEX    Nguiu
 7 FIELDS:   UZ  R1:  0.000  GS: 0.300  NG: 480  EC:
             CZ  R1:  0.000  GS: 0.300  NG: 480  EC:
             VR  R1:  0.000  GS: 0.300  NG: 480  EC:
             SW  R1:  0.000  GS: 0.300  NG: 480  EC:
             ZD  R1:  0.000  GS: 0.300  NG: 480  EC:
             PH  R1:  0.000  GS: 0.300  NG: 480  EC:
             RH  R1:  0.000  GS: 0.300  NG: 480  EC:

Type the number of records to be read in 32000

Type the beam skip factor (optional)

-1 = Start over
 0 = Continue
 1 = Azimuth subsectioning
 2 = Elevation subsectioning
 3 = Specify the max. no. of gates per field

Select option

DEFAULT CASE: Use the range to the first gate (R1), the gate
              spacing (GS) and the no. of gates in the first
              field in the volume

-1 = Start over
 0 = Default
 1 = Enter R1, GS, etc.

Select option
Enter the fields to be input from the tape.

Type 2 character field mnemonic (0=Cease) cz

Type up to 40 characters of description for this field reflectivity
If there is an error in the range to the first gate (R1)
in the input data set, then
type R1 error
If there is an error in the gate spacing (GS) ...
type GS error

Type 2 character field mnemonic (0=Cease) zd

Type up to 40 characters of description for this field differential reflectivity
type R1 error
type GS error

Type 2 character field mnemonic (0=Cease) ph

Type up to 40 characters of description for this field phase shift
type R1 error
type GS error

Type 2 character field mnemonic (0=Cease) rh

Type up to 40 characters of description for this field correlation coeff
type R1 error
type GS error

Type 2 character field mnemonic (0=Cease) vr

Type up to 40 characters of description for this field radial velocity
type R1 error
type GS error

Type 2 character field mnemonic (0=Cease)

You have asked for 5 fields of 480 gates each.
Space for two scratch fields will be added.

Hit  to continue ... or
type number of scratch fields required:  5 (usually same as # of fields
                                            so you have space for copies)

Hit  to start input
F: 1 R:   2 L:3664 B:    2 05:08:34 A:270. E:  0.7 F:  0.7 PPI S:  1 G: 0.30
F: 1 R:  32 L:3664 B:   32 05:08:38 A:307. E:  0.7 F:  0.7 PPI S:  1 G: 0.30
F: 1 R:  62 L:3664 B:   62 05:08:42 A:344. E:  0.7 F:  0.7 PPI S:  1 G: 0.30
F: 1 R:  92 L:3664 B:   92 05:08:46 A: 20. E:  0.7 F:  0.7 PPI S:  1 G: 0.30
F: 1 R: 122 L:3664 B:  122 05:08:50 A: 57. E:  0.7 F:  0.7 PPI S:  1 G: 0.30
F: 2 R: 152 L:3664 B:  152 05:08:56 A: 89. E:  2.0 F:  2.2 PPI S:  3 G: 0.30
F: 2 R: 182 L:3664 B:  182 05:08:59 A: 52. E:  2.1 F:  2.2 PPI S:  3 G: 0.30
.
.
. (etc)


        0 = EXIT this program
        1 = Tape/disk input
        2 = Access an editor file
        3 = Editing and display
        4 = Tape/disk output
        5 = On line documentation

Select next course of action: 3

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

Select the next process number (1 for list): 1
*******************************************************

        2 = Session control 
        3 = Tape functions
        5 = Plot next scan 
        11 = Change current active disk file number
        22 = List known field mnemonics and their descriptions
        67 = Zap the Plot Parameter and Boundary tables
        76 = Scan or volume table modification 
        77 = Display beam numbers, azimuths, elevations, etc.
        78 = Display beam contents gate by gate 
        85 = Display header beam by beam 
        86 = Display housekeeping beam by beam 
        88 = Scan table contents 
        89 = Table buffer contents 
        90 = Change the contents of a table buffer 
        91 = Display fields in a beam

Hit  to continue 

        123 = Annotate color plots 
        188 = Volume table contents 
        321 = Forward and backward azimuth links 
        322 = Subsection data 
        331 = Copy data from secondary to primary data file
        332 = Generate a new file with a different block size
        333 = Change housekeeping 
        334 = Beam by beam deletion 
        335 = Convert dbm to dbz 
        336 = Convert ncp to standard deviation 
        350 = Shift a field relative to the rest
        353 = Filtering (Q&D Kalmann) in azimuth and range 
        360 = Blaskovic special matrix process

Hit  to continue 

        430 = Correction of bad NCP data
        431 = Change the scale of the data 
        432 = Functional modification of data (ax+b)

The following processes can use the polygon boundary.

        440 = Ground clutter removal
        ------------------------------ 
        441 = Difference of two fields 
        ------------------------------ 
        442 = Radial gate to gate differencing 
        443 = Copy from 1 field to another 
        444 = Remove (delete) unwanted data 
        445 = Forced velocity unfolding 
        446 = RSF velocity unfolding alogrithm 
        447 = ZDR filtering  [Chill]
        449 = Despeckling algorithm 
        454 = Thresholded copy from 1 field to another
        456 = Subtract storm motion 
        460 = Histograms

Hit  to continue 

        542 = Change target window display parameters
        543 = Modify targeted data points 
        544 = Delete targeted data points 
        545 = Change nyquist interval of targeted data points
        547 = Inspect targeted data points 

        555 = Color plots (primary) 
        556 = Irregular boundary definition or modification 
              using the target 
        557 = Generate range and angle grid in a graphic image
        558 = Generate a cartesian grid in a graphics image 

        664 = Rhi from ppi color plots 
        666 = Cappi color plots
        667 = Vertical slice plots (RAMTEK only)
        668 = Cartesian grid for vertical slice plots.
        670 = Mesonet data plots or overlays.

Editor is an interactive, menu-based piece of software that is useful but old (interface technology circa early 1980's). Each command above is begun by entering the number and hitting return. Some of the more common commands are:

1. 555: display's PPI's of up to 4 variables at once.

2. 664: display's RHI's of up to 4 variables at once.

3. 557: Generate range rings on your display.

4. 558: Generate a 2-D grid on your display.

5. 443: Makes copies of a data variable.

6. 444: Deleting data (either thresholded or not).

7. 556: Creating boundaries for editing (ie deleting or unfolding).

8. 445: Manual velocity unfolding routine.

9. 547: You can inspect data points using the mouse.

10. 460: Create Histograms of data.

11. 447: Inspect Grad-Z problems for Zdr

12. 432: Modify data by a multiplicative and/or additive constant

To view your data in PPI mode, use 555 and 664 for RHI mode. The menus are similar for both except you must choose an azimuth in 664 mode. For polarimetric data, RDSS will often not choose appropriate plotting ranges. Use option "3 = Change the plot parameters " to change the magnification, location of the plots, variables plotted, and range of values plotted for each variable. The menus are fairly self-explanatory. Give it a try.

Editing and QC'ing is a critical first step in analyzing any radar data but especially with polarimetric radar data. Your editing requirements will vary with each radar and each case. However, here are some guidelines and hints to get you started:

1. First, it is often wise to make copies of variables that your are editing in case you make a mistake (it is better than starting from scratch). Use command 443 to make a copy:


Select the next process number (1 for list): 443

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process copies data from one field to another field 

 1)  CZ  Anonymous
 2)  ZD  Anonymous
 3)  RH  Anonymous
 4)  PH  Anonymous
 5)  VR  Anonymous
 6)  ZT  grad Z > 20 dbZ/km


Type source field mnemonic CZ
Type destination field mnemonic ZH

Type up to 40 characters describing this field copy of CZ

-1 = EXIT 
 0 = Use boundary 
 1 = Do not use boundary 
 2 = Enter azimuth or range limits 

Select option 1

-1 = EXIT 
 0 = Continue 
 1 = Enter azimuth limits 
 2 = Enter range limits 

Select option 

-1 = EXIT 
 0 = Process last scan plotted 
 1 = Choose the scan to process 
 2 = Process a volume 
 3 = Enter beam limits of process 

Select option 2

Type the volume no. 1

Hit  to start process 

2. If you are working with polarimetric data, then you should be concerned with the effects of mis-matched sidelobes in areas of high reflectivity gradients (ie grad-Z>20 dBZ/km) on your measurement of Zdr (also LDR and rhoHV). To investigate this possibility, run option 447 as follows:


Select the next process number (1 for list): 447

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process does a thresholded copy of the ZDR field 
using the reflectivity gradient as a threshhold 

Threshold field values greater than the threshold 
cause a deletion in the destination field. 

 The default ZDR source field mnemonic is ZD

-1 = EXIT this process 
 0 = Default ... or 
Type ZDR source field mnemonic 

 The default ZDR destination field mnemonic is ZT

Hit  for default ... or 
Type ZDR destination field mnemonic 

Type up to 40 characters describing this field grad Z > 20 dbZ/km

 The default reflecivity threshold field mnemonic is DZ

Hit  for default ... or 
type threshold field mnemonic CZ

 The threshhold is a linear function specified by a slope and
 intercept.
Enter the slope 0.0
Enter the intercept 20.0 (note: this # is not written in stone)

This program will delete all gates of Zdr for which grad Z exceeds the threshold you specify and place the results in ZT. This tool is best used as a guideline. Compare the Zdr pattern with potential problem areas located by 447. If Zdr seems physically too high in a region deleted by 447, then it is probably an artifact and should either be removed or appropriately noted as artifact.

3. Otherwise, you should begin by thresholding noise out of your data using power (DM), the correlation coefficient (RX or RH), and/or reflectivity (DZ or ZH) depending on what is available to you. This can be accomplished with a thresholded, volume wide delete using option 444 as follows:


Select the next process number (1 for list): 444

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process is for removing unwanted data in up to 5 fields

        -1 = EXIT 
         0 = Unconditional delete 
         1 = Test on one field 
         2 = Test on two fields 

Select option 1

Type test field mnemonic rx

Choice of a single bound implies the other is unbounded 

        0 = Apply both the lower and upper bounds 
        1 = Apply only the lower bound 
        2 = Apply only the upper bound 

Select option 1
Type the lower bound 0.7 (note: this # is not written in stone)

        0 = Data outside the bounds will be removed 
        1 = Data inside the bounds will be removed 

Select option 

Enter field mnemonic(s) in which deletion occurs 

0 = Cease ... else type field mnemonic dz

0 = Cease ... else type field mnemonic dr

0 = Cease ... else type field mnemonic dp

0 = Cease ... else type field mnemonic vr

0 = Cease ... else type field mnemonic rx

-1 = EXIT 
 0 = Use boundary 
 1 = Do not use boundary 
 2 = Enter azimuth or range limits 

Select option 1

-1 = EXIT 
 0 = Continue 
 1 = Enter azimuth limits 
 2 = Enter range limits 

Select option 

-1 = EXIT 
 0 = Process last scan plotted 
 1 = Choose the scan to process 
 2 = Process a volume 
 3 = Enter beam limits of process 

Select option 2

Type the volume no. 1

Hit  to start process 

You should choose the best thresholds that suit your particular situation.

4. You should manually remove ground clutter (and other spurious data such as 2nd-trip echoes and flare echoes, unless your studying them!) using the 556 and 444 commands as follows.

Select the next process number (1 for list): 556

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

-1 = Exit 
 0 = Target points for the irregular boundary 
 1 = Clear boundary table 
 2 = Clear boundary overlay 
 3 = Remove the last point from the boundary 
 4 = Additional options 

Select option: 1

-1 = Exit 
 0 = Target points for the irregular boundary 
 1 = Clear boundary table 
 2 = Clear boundary overlay 
 3 = Remove the last point from the boundary 
 4 = Additional options 

Select option: 

Which window? 1

Use the LEFT mouse button to target points.
Use the MIDDLE button to erase the last point.
Use the RIGHT button when you are done.

(Using the mouse, create a boundary around the area you wish to delete.)

ENTRY   1  AZ= 97.59  RANGE=  17.29  
ENTRY   2  AZ= 71.57  RANGE=  14.46  
ENTRY   3  AZ= 51.71  RANGE=  13.83  
.
. (etc...) 
 
-1 = Exit 
 0 = Target points for the irregular boundary 
 1 = Clear boundary table 
 2 = Clear boundary overlay 
 3 = Remove the last point from the boundary 
 4 = Additional options 

Select option: -1

Select the next process number (1 for list): 444

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process is for removing unwanted data in up to 5 fields

0 = Cease ... else type field mnemonic cz

0 = Cease ... else type field mnemonic zd

0 = Cease ... else type field mnemonic ph

0 = Cease ... else type field mnemonic rh

0 = Cease ... else type field mnemonic vr

-1 = EXIT 
 0 = Use boundary 
 1 = Do not use boundary 
 2 = Enter azimuth or range limits 

Select option 

-1 = EXIT... 
Else apply the process 
 0 = Inside the boundary 
 1 = Outside 
 2 = Beyond...(from the boundary to the end of the data) 
 3 = Before...(from the radar to the boundary) 

Select option 

-1 = EXIT 
 0 = Process last scan plotted 
 1 = Choose the scan to process 
 2 = Process a volume 
 3 = Enter beam limits of process 

Select option 


Hit  to start process 
DELTE1 5683 GATES EXAMINED 5683 DELETED  

5. Unfold velocity field (or phidp if you're using MCTEX data). If you need to change the Nyquist interval because it is wrong in the UF file or because you want to unfold phidp, follow this procedure first.

CHANGING NYQUIST:

Select the next process number (1 for list): 333

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process modifies housekeeping parameters 

-1 = Exit this process 
 0 = Continue 
 1 = Apply changes to a scan 
 2 = Apply changes to a volume 
 3 = Specify beam limits for changes 
 4 = Apply changes to every beam in the file 

Select option 2

Type the volume number 1

-1 = Exit this process 
 0 = Continue 
 1 = The change is a constant 
 2 = Change an angle 
 3 = Change the time 
 4 = Preprogrammed special function (check first) 
 5 = Change experiment name, site, radar, etc. 
 6 = Change range to first gate and spacing 
 7 = Start over 

Select option 1
Type the housekeeping word number 199
Type the new contents of this word 2500  <---- This is 25 m/s (*100)

-1 = Exit this process 
 0 = Continue 
 1 = The change is a constant 
 2 = Change an angle 
 3 = Change the time 
 4 = Preprogrammed special function (check first) 
 5 = Change experiment name, site, radar, etc. 
 6 = Change range to first gate and spacing 
 7 = Start over 

Select option (Don't forget to hit 0 or RETURN here)

TO UNFOLD/DEALIAS (ie. correct velocities which wrap since they are larger than the unambiguous velocity):

(For MCTEX data, this technique can be used for phidp unfolding as well).

a. After making a copy of your velocity (VT or VR usually), display VT in one of the windows using 555. Using the same technique as above for clutter removal, draw a polygon tightly around the area that is aliased.

b. Use option 445 (forced velocity unfolding...use 446 RSF velocity unfolding algorithm at your own risk!). Type in an appropriate velocity threshold. If the fold is in a -/+ velocity field (ie folds to +/- values), then choose a -/+ number close to the Nyquist value (ie if 25 m/s then choose -/+ 24.9). Process the last scan plotted, inside the boundary. Here is an example:


Select the next process number (1 for list): 445

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

This process does forced velocity unfolding 

Hit  to use the default mnemonic   VT
else type the mnemonic of the field to be unfolded 

Type the center of the unfolded interval -24.9

-1 = EXIT 
 0 = Use boundary 
 1 = Do not use boundary 
 2 = Enter azimuth or range limits 

Select option 

-1 = EXIT... 
Else apply the process 
 0 = Inside the boundary 
 1 = Outside 
 2 = Beyond...(from the boundary to the end of the data) 
 3 = Before...(from the radar to the boundary) 

Select option 

-1 = EXIT 
 0 = Process last scan plotted 
 1 = Choose the scan to process 
 2 = Process a volume 
 3 = Enter beam limits of process 

Select option 


Hit  to start process 
 THE NYQUIST VELOCITY IS   25.00 M/S 
FUNFOL 5683 GATES EXAMINED 439 UNFOLDED 

c. Use 555 to replot the same scan and check your work. If you made a mistake, use 443 to copy that scan (and that one only!) from your extra copy of velocity back to VT.

6. Lastly, if you are using the differential reflectivity, Zdr, then you should investigate the possibility of a Zdr bias (ie an artificial offset in Zdr caused by various calibration and other engineering factors). To do this, use 555 to plot Zdr to screen at one of the highest elevation angles available (>20 degrees is required) in which there is little or no heavy precipitation close to the radar. Use option 460 to construct a histogram of Zdr in 0.25 dB bins. If the absolute value of the area-weighted average Zdr (found by looking at the output) is > 0.2 dB, then option 432 should be used to shift the distribution back toward zero where it should be on average for these high elevation angles in small ice crystals and aggregates aloft. For example:

Select the next process number (1 for list): 460

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

Bin type: regular increments.
Lower limit: -10.00.  Increment: 5.00.  # steps: 17.
Source field: DZ.
Histogram will be done by areas.


        -1 = Exit.
         0 = Start the histogram process
         1 = Change the histogram bins
         2 = Display custom bin limits
         3 = Reinitialize the parameter table
         4 = Specify the source field
         5 = Change the histogram output
         6 = Change the gate weighting scheme

Select option: 4

Enter the source field mnemonic: dr

Bin type: regular increments.
Lower limit: -10.00.  Increment: 5.00.  # steps: 17.
Source field: DR.
Histogram will be done by areas.


        -1 = Exit.
         0 = Start the histogram process
         1 = Change the histogram bins
         2 = Display custom bin limits
         3 = Reinitialize the parameter table
         4 = Specify the source field
         5 = Change the histogram output
         6 = Change the gate weighting scheme

Select option: 5

Terminal output is ENABLED.
File output is DISABLED.

        0 = Return to previous menu
        1 = Toggle terminal output flag
        2 = File output

Select option: 2

0 = No file output, 1 = yes file output: 1
Enter file name: zdr_test
0 = Create new version each time, 1 = Append to old version 1

Terminal output is ENABLED.
File output will be appended to zdr_test.hst

        0 = Return to previous menu
        1 = Toggle terminal output flag
        2 = File output

Select option: 

Bin type: regular increments.
Lower limit: -10.00.  Increment: 5.00.  # steps: 17.
Source field: DR.
Histogram will be done by areas.


        -1 = Exit.
         0 = Start the histogram process
         1 = Change the histogram bins
         2 = Display custom bin limits
         3 = Reinitialize the parameter table
         4 = Specify the source field
         5 = Change the histogram output
         6 = Change the gate weighting scheme

Select option: 1

Histogram bins.

        -1 = Return to previous menu
         0 = Use regularly spaced bins
         1 = Use custom bins

Select option: 

Enter lower bin limit: -2
Enter bin increment:   0.25
Enter number of bins:  25

Bin type: regular increments.
Lower limit: -2.00.  Increment: 0.25.  # steps: 25.
Source field: DR.
Histogram will be done by areas.

        -1 = Exit.
         0 = Start the histogram process
         1 = Change the histogram bins
         2 = Display custom bin limits
         3 = Reinitialize the parameter table
         4 = Specify the source field
         5 = Change the histogram output
         6 = Change the gate weighting scheme

Select option: 

-1 = EXIT 
 0 = Use boundary 
 1 = Do not use boundary 
 2 = Enter azimuth or range limits 

Select option 1

-1 = EXIT 
 0 = Continue 
 1 = Enter azimuth limits 
 2 = Enter range limits 

Select option 

-1 = EXIT 
 0 = Process last scan plotted 
 1 = Choose the scan to process 
 2 = Process a volume 
 3 = Enter beam limits of process 

Select option 

Hit  to start process 
Less than -2.00       0.04 |
  -2.00 to   -1.75    0.13 |
  -1.75 to   -1.50    0.01 |
  -1.50 to   -1.25    0.03 |
  -1.25 to   -1.00    0.17 |
  -1.00 to   -0.75    0.03 |
  -0.75 to   -0.50    0.39 |
  -0.50 to   -0.25    1.87 |
  -0.25 to    0.00    4.36 |#
   0.00 to    0.25   35.38 |############
   0.25 to    0.50   52.27 |##################
   0.50 to    0.75  146.15 |####################################################
   0.75 to    1.00   57.23 |####################
   1.00 to    1.25   36.27 |############
   1.25 to    1.50    8.96 |###
   1.50 to    1.75    7.01 |##
   1.75 to    2.00    1.47 |
   2.00 to    2.25    1.66 |
   2.25 to    2.50    0.29 |
   2.50 to    2.75    0.29 |
   2.75 to    3.00    0.00 |
   3.00 to    3.25    0.21 |
   3.25 to    3.50    0.00 |
0 = Continue, 1 = Cease terminal output 
   3.50 to    3.75    0.01 |
   3.75 to    4.00    0.01 |
   4.00 to    4.25    0.00 |
Greater than 4.25     0.02 |
(By viewing zdr_test.hst, we see that the average Zdr was 0.62.)
Hit  to continue 

Select the next process number (1 for list): 432

Current active file no.: 1    Name: /usr/tmp/carey/MCTEX_951117_0508.red

functional modification of the data of the form Y = A*X +B
for single beams or beam runs 

-1 = EXIT THIS PROCESS 
 0 = +B ONLY 
 1 = A*X ONLY 
 2 = A*X +B 

Select option 0

 1)  DZ  Horizontal Reflectivity
 2)  DR  Differential Reflectivity
 3)  RX  Correlation Coefficient
 4)  DP  Phase shift
 5)  VT  Velocity
 6)  ZT  grad Z > 20 dbZ/km


Type the mnemonic field to be modified dr

0 = Apply to all gates in beam 
1 = Select gate limits of application 
Select option 

-1 = EXIT this process 
 0 = A beam run 
>0 = Perform modification on this beam no. 

Select option 
Type first beam in run 1
Type last beam in run 5000
Out of range -1 to 2356 -- try again
Type last beam in run 2356
B =  -0.62

The best way to learn editor (RDSS) is to play with it! Have fun!