6.6.15 Measurement Data Set containing spectra.
1 MDSR per spectra.
This Measurement Data Set (MDS)
contains the cross spectrum of the imagette . There is one MDSR
per wave cell. The format of each MDSR is
described in the table below:

Table 6.52 Measurement Data Set containing spectra. 1 MDSR per spectra

Measurement Data Set
containing spectra. 1 MDSR
per spectra.

#

Description

Units

Count

Type

Size

Data Record

0

zero_doppler_time
First Zero Doppler
Azimuth time of the wave
cellTime of first range line in
the SLC Imagette MDS described
by this data set 
MJD 
1 
mjd 
12 byte(s) 
1

quality_flag
Quality Indicator
(1 for blank MDSR, 0 otherwise) 
flag 
1 
BooleanFlag 
1 byte(s) 
2

range_spectral_res
Range bin size of
the cartesian cross spectrum 
 
1 
fl 
4 byte(s) 
3

az_spectral_res
Azimuth bin size
of the cartesian cross spectrum 
 
1 
fl 
4 byte(s) 
4

spare_1
Spare 
 
1 
SpareField 
4 byte(s) 
5

spec_tot_energy
Spectrum Total Energy 
 
1 
fl 
4 byte(s) 
6

spec_max_energy
Spectrum Max Energy 
 
1 
fl 
4 byte(s) 
7

spec_max_dir
Direction of
Spectrum Max (deg)
On higher resolution
grid. Direction is
counterclockwise from
satellite track heading

deg 
1 
fl 
4 byte(s) 
8

spec_max_wl
Wavelength of
Spectrum Max (m)
On higher resolution grid

m 
1 
fl 
4 byte(s) 
9

clutter_noise
Clutter Noise 
 
1 
fl 
4 byte(s) 
10

az_cutoff
Azimuthal Clutter
Cutoff length (m) 
m 
1 
fl 
4 byte(s) 
11

num_iterations
Number of
iterations to compute Azimuthal
Clutter Cutoff 
 
1 
fl 
4 byte(s) 
12

range_offset
Range offset of
peak of cross covariance
function (m) 
m 
1 
fl 
4 byte(s) 
13

ax_offset
Azimuth offset of
peak of cross covariance
function (m) 
m 
1 
fl 
4 byte(s) 
14

cc_range_res
Range bin size of
cross covariance function (m) 
m 
1 
fl 
4 byte(s) 
15

cc_azimuth_res
Azimuth bin size
of cross covariance function (m) 
m 
1 
fl 
4 byte(s) 
16

sublook_means
1st and last
Sublook Image Means 
 
2 
fl 
2*4 byte(s) 
17

sublook_variance
1st and last
Sublook Image Variance 
 
2 
fl 
2*4 byte(s) 
18

sublook_skewness
1st and last
Sublook Image Skewness 
 
2 
fl 
2*4 byte(s) 
19

sublook_kurtosis
1st and last
Sublook Image Kurtosis 
 
2 
fl 
2*4 byte(s) 
20

range_sublook_detrend_coeff
1st and last
Sublook detrend coefficient in range 
 
2 
fl 
2*4 byte(s) 
21

az_sublook_detrend_coeff
1st and last
Sublook detrend coefficient in azimuth 
 
2 
fl 
2*4 byte(s) 
22

min_imag
Min value of
Imaginary part of cross spectrum 
 
1 
fl 
4 byte(s) 
23

max_imag
Max value of
Imaginary part of cross spectrum 
 
1 
fl 
4 byte(s) 
24

min_real
Min value of Real
part of cross spectrum 
 
1 
fl 
4 byte(s) 
25

max_real
Max value of Real
part of cross spectrum 
 
1 
fl 
4 byte(s) 
26

spare_2
Spare 
 
1 
SpareField 
64 byte(s) 
27

real_spectra
Real part of
cross spectra polar grid
Number of bins in
wavelength and direction
defined in SPH (nominally 24
by 36). However, only 0 to
180 degree of the spectrum
need be supplied
(24 by 18). Arranged as: 24
wavelength values for [5,5]
deg. sector, 24 values for
[5,15] deg. sector, ..., 24
values for
[165,175] deg. sector, in
the counterclockwise
direction. The 24 values for
each sector are given in
order from longest to
shortest wavelength.

 

uc 
1 byte(s) 
28

imag_spectra
Complex part of
cross spectra polar grid
Number of bins in
wavelength and direction
defined in SPH (nominally 24
by 36). However, only 0 to
180 degree of the spectrum
need be supplied
(24 by 18). Arranged as: 24
wavelength values for [5,5]
deg. sector, 24 values for
[5,15] deg. sector, ..., 24
values for
[165,175] deg. sector, in
the counterclockwise
direction. The 24 values for
each sector are given in
order from longest to
shortest wavelength.

 

uc 
1 byte(s) 
DS_NAME : Measurement Data Set containing
spectra. 1 MDSR per spectra.
Format Version 114.0
Notes:
The cross spectrum is given in the MDS in complex
form on a polar grid. The size of the cross
spectrum grid is given in the SPH . Typically this will be
24 by 36 bins in wavelength and direction respectively. As the
real part of the polar spectrum is
symmetric, and the imaginary part is
antisymmetric, only 0 to 180 need to be given
in order to reconstruct the entire spectrum
(i.e., only 18 directional bins).
The cross spectrum values shall be stored in an
unsigned integer format, each part linearly
scaled to the maximum and minimum values of
the representation (e.g., 0 to 255). The
original maximum and minimum values for each
part is reported.
The cross spectrum statistics are derived from a
highresolution polar spectrum, prior to
encoding for output to the product, or at
other intermediate stages of the processing.
If the processor is unable to produce the cross
spectra for a given wave cell, the MDSR is time
stamped with the time that the cross spectra
would have corresponded to, the Quality Flag is set to 1,
and the MDSR data fields are all set to zero.
The format of the Wave Mode cross spectrum
product is given in the section entitled " Wave Spectra " .1.59
