Passive/Active Radar: Electromagnetic Scattering Data (Restricted Access)
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FISC CAD models
 t38a_aligned.facet is a
model of a T38A training aircraft adapted from a file purchased from
Viewpoint Digital  falcon100_aligned.facet is a
model of a Dassault Aviation Falcon 100 adapted from a file purchased from
Viewpoint Digital  falcon_20.facet is an approximate model of the
Dassault Aviation Falcon 20. To make this, we simply scaled the
Falcon 100 model to be the same dimensions as the real Falcon 20 (which is
quite similar to the Falcon 100, but larger.)  aaron_sphere.facet is a sphere with a
diameter of 15 meters  standing_square.facet is a flat square
plate square, 15 meters along each side standing vertically, lined up along
the xaxis.  lying_square.facet is a flat square
plate, 15 meters along each side lying horizontally (looks completely thin
when viewed at 0 degrees elevation)
Lower VHF FISC data
The following MATLAB files each contain four variables (containing
complex farfield values): fisc_hh, fisc_hv,
fisc_vh, and fisc_vv, each corresponding to a different polarization.
Each variable is a 5 by 360 by 37 array (expect for aaron_sphere_vhf.mat,
which is just a 5 by 360 array). The first dimension corresponds to the
five frequencies associated with NTSC TV channels 2 through 6
(55.25 to 79.25 MHz, with a 6 MHz spacing.) The second dimension corresponds
to the observation azimuth angle, ranging from 0 to 359 in 1 degree
increments. The final dimension corresponds to the incident azimuth angle,
ranging from 0 to 180 in 5 degree increments. For the aircraft, 0 degree
is looking at the nose, 90 degree at the side, and 180 degree at the tail.
The elevation angle (both observed and incident) is zero degrees.
 aaron_sphere_vhf.mat
 standing_square_vhf.mat
 lying_square_vhf.mat
 vfy_vhf.mat (for the VFY218 that comes with
FISC)  falcon100_vhf.mat
 falcon20_vhf.mat
The sphere file only needs one incident angle due to symmetry.
The above files were created using a special version of FISC that can
loop through both incident and observed angles in one run. The input files
were
 aaron_sphere_vhf.fisc_input

standing_square_vhf.fisc_input 
lying_square_vhf.fisc_input  vfy_vhf.fisc_input

falcon100_vhf.fisc_input 
falcon20_vhf.fisc_input
(runtime: 2 days, 1 hr, 26 min on mimir.ncsa,
4 processes, peak memory: 1.43G (?))
After reading the *.field file output by FISC using read_fisc_field_file
(given below), fisc_vv, etc. were created by entering commands like this
into MATLAB:
num_freqs = 5; num_obs = 360; num_inc = 37;
fisc_hh = reshape(hh,num_freqs,num_obs,num_inc);
fisc_vv = reshape(vv,num_freqs,num_obs,num_inc);
fisc_vh = reshape(vh,num_freqs,num_obs,num_inc);
fisc_hv = reshape(hv,num_freqs,num_obs,num_inc);
save vfy_vhf fisc_hh fisc_hv fisc_vh fisc_vv
30 Degree Elevation, Lower VHF FISC Data
These are FISC data files, for channels 26,
in the same MATLAB format described above,
except at 30 degrees elevation (either plus or minus). They were created
by Michael Brandfass.
Higher VHF FISC data
Like above, except each variable is a 7 by 360 by 91 array.
The first dimension corresponds to the
seven frequencies associated with NTSC TV channels 7 through 13
(175.25 to 211.25 MHz, with a 6 MHz spacing.) The second dimension corresponds
to the observation azimuth angle, ranging from 0 to 359 in 1 degree
increments. The final dimension corresponds to the incident azimuth angle,
ranging from 0 to 180 in 2 degree increments.
The elevation angle (both observed and incident) is zero degrees.
The input files were
 vfy_vhfhigh.fisc_input
(runtime: 3 days, 2 hr, 24 min on jord1.ncsa, 1 process, peak memory:
93.9M) 
falcon100_vhfhigh.fisc_input
(runtime: 5 days, 16 hr, 17 min on jord1.ncsa, 1 process, peak memory: 576.6M) 
falcon20_vhfhigh.fisc_input
(runtime: 3 days, 9 hr, 56 min on jord1.ncsa, 8 processes, peak memory: 659.6M)
The MATLAB files were made from the field file as above, except here
num_freqs = 7; num_obs = 360; num_inc = 91;
FM radio FISC data
Like above, except each variable is a 4 by 360 by 61 array.
The first dimension corresponds to radio stations at frequencies
88, 94, 100, and 106 MHz. The second dimension corresponds
to the observation azimuth angle, ranging from 0 to 359 in 1 degree
increments. The final dimension corresponds to the incident azimuth angle,
ranging from 0 to 180 in 3 degree increments.
The elevation angle (both observed and incident) is zero degrees.
The input files were
 vfy_fmradio.fisc_input
(runtime: 18 hr, 15 min on saga1.ncsa, 1 process, peak memory:
159.7M) 
falcon100_fmradio.fisc_input
(runtime: 2 days, 7 hr, 46 min on huldra.ncsa, 1 process, peak memory: 570.0M) 
falcon20_fmradio.fisc_input
(runtime: 2 days, 12 hr, 25 min on mimir.ncsa,
1 processes, peak memory: 678.0M)
The MATLAB files were made from the field file as above, except here
num_freqs = 4; num_obs = 360; num_inc = 61;
2D Helmholtz Data
Moving away from FISC for a moment, the data sets found here are from
a 2D scenario where the scatterer is assumed to be an infinitely long
cylinder with a crosssection profile given by some 2D shape. If the
incident wave is polarized so that the electric or magnetic field runs
along the axis of the scatterer, Maxwell’s equations reduce to the
much simpler scalar Helmholtz equation.
Each MATLAB file here contains four variables: tm_100, tm_200, te_100,
and te_200. These correspond to the transverse magnetic (TM) and
transverse electromagnetic (TE) cases, and with incident frequencies
of 100 and 200 MHz. The data was simulated using Karl Warnick’s
fantastic 2D scattering code. Each variable is a 120 by 120 array
containing the complex far field for different incident and observed
angles, with an angular spacing of 3 degress (yielding full aperture
data). The different files correspond to different objects, which
are the topdown profiles of a B2
artifically scaled to have a wingspan of 15.5 meters, an F15
(19.5 meters long), a VFY218 (15.5 meters long),
and a YF23 (20.5 meters long).
The associated *.txt files give the 2D coordinates of the
vertices of the objects.
 b2_far_fields.mat (from
b2_coordinates.txt)  f15_far_fields.mat (from
f15_coordinates.txt)  vfy_far_fields.mat (from
vfy_coordinates.txt)  yf23_far_fields.mat (from
yf23_coordinates.txt)
MATLAB Code
 read_fisc_field_file.m
(by Aaron Lanterman):
For painless loading of FISC field files into MATLAB
Last updated 3/5/01. Send comments or questions to
lanterma@ifp.uiuc.edu.