Synthetic aperture focusing technique (SAFT) and total focusing method (TFM) have become popular tools in the field of ultrasonic non destructive testing. In particular, they are employed for detection and characterization of flaws. From data acquired with a transducer array, those techniques aim at reconstructing an image of the inspected object from coherent summations. In this paper, we make a comparison between the standard technique and a migration approach. Using experimental data, we show that the developed approach is faster and offers a better signal to noise ratio than the standard total focusing method. Moreover, the migration is particularly effective for near-surface imaging where standard methods used to fail. On the other hand, the migration approach is only adapted to layered objects whereas the standard technique can fit complex geometries. The methods are tested on homogeneous pieces containing artificial flaws such as side drilled holes.

1.
J.
Krautkramer
and
H.
Krautkramer
,
Ultrasonic Testing of materials
(
Springer-Verlag
,
Berlin
,
1990
).
2.
B. W.
Drinkwater
and
P. D.
Wilcox
,
NDT & E International
39
,
525
541
(
2006
).
3.
J.
Seydel
,
Research techniques in nondestructive testing
6
,
1
47
(
1982
).
4.
M.
Karaman
,
P.-C.
Li
, and
M.
O’Donnell
,
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
42
,
429
442
(
1995
).
5.
F.
Lingvall
,
T.
Olofsson
, and
T.
Stepinski
,
The Journal of the Acoustical Society of America
114
,
225
234
(
2003
).
6.
C.
Holmes
,
B. W.
Drinkwater
, and
P. D.
Wilcox
,
NDT&E International
38
,
701
711
(
2005
).
7.
M.
Sutcliffe
,
M.
Weston
,
B.
Dutton
,
P.
Charlton
, and
K.
Donne
,
NDT&E International
51
,
16
23
(
2012
).
8.
R. H.
Stolt
,
Geophysics
43
,
23
48
(
1978
).
9.
T.
Stepinski
,
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
54
,
1399
1408
(
2007
).
10.
A. J.
Hunter
,
B. W.
Drinkwater
, and
P. D.
Wilcox
,
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
55
,
2450
2462
(
2008
).
11.
R.
Hanssen
and
R.
Bamler
,
IEEE Transactions on Geoscience and Remote Sensing
37
,
318
321
(
1999
).
12.
T.
Olofsson
,
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
57
,
2522
2530
(
2010
).
13.
A.
Tuysuzoglu
,
J. M.
Kracht
,
R. O.
Cleveland
,
M.
Cetin
, and
W. C.
Karl
,
The Journal of the Acoustical Society of America
131
,
1271
1281
(
2012
).
14.
G.
Dao
,
D.
Braconnier
, and
M.
Gruber
, “Full matrix capture with a customizable phased array instrument,” in
Review of Progress in Quantitative Nondestructive Evaluation
, (
American Institute of Physics
,
Melville NY
), Vol.
1650
(Boise, USA, 2014
), pp.
1001
1006
.
15.
E.
Carcreff
,
G.
Dao
, and
D.
Braconnier
, “Total focusing method for flaw characterization in homogeneous media,” in
14ᵗʰ International Symposium on Nondestructive Characterization of Materials
(
Marina Del Rey
,
USA
,
2015
).
This content is only available via PDF.