Photogrammetric Surveying of the Costa...

Photogrammetric Surveying

of the Costa Concordia

Fabio Mennaa, Erica Nocerinoa,b, Salvatore Troisib, Fabio Remondinoa

a3D Optical Metrology Unit, FBK Trento, Italy

Email: <fmenna><nocerino><remondino>@fbk.eu, Web: http://3dom.fbk.eu bDepartment of Sciences and Technologies, Parthenope University of Naples, Italy

Email: [email protected]

10-11 September 2013, Mercure Manchester Picadilly

Large Volume Metrology Conference & Exhibition 2013

In cooperation with

Menna, Nocerino, Troisi, Remondino - Photogrammetric Surveying of the Costa Concordia 2

THE ACCIDENT OF “COSTA CONCORDIA” CRUISE SHIP

• On 12/01/2012, the Italian cruise ship Costa Concordia partially sank off the coast of

Isola del Giglio after she struck her port side on a reef known as Le Scole.

Images in this slide taken from: http://it.wikipedia.org/wiki/Naufragio_della_Costa_Concordia



• After the collision, the ship, without neither steering control nor propulsive power, ran

aground close to the Giglio Porto harbour entrance, leaning with the starboard side

against the seafloor with a final inclination angle of about 70 degrees.

The accident is well known worldwide, for both the dynamics (the impact happened very

close to the shoreline in very shallow water) and the tragic consequences in terms of

human lives and environmental pollution.

Images in this slide taken from: http://it.wikipedia.org/wiki/Naufragio_della_Costa_Concordia



• Soon after the event, criminal proceedings were instituted for ascertaining the causes

of the disaster.

Within the legal action, we were designated to measure the dimensions and determine

the characteristics of the leak produced by the collision of the ship with the rocks, with

high accuracy and non-invasive technique.

http://it.wikipedia.org/wiki/Naufragio_della_Costa_Concordia


INTRODUCTION

OptiMMA

OPTical Metrology for Maritime Applications

• Project started in 2006 at the Parthenope University as an

interdisciplinary work

• Since 2011 supported by 3DOM – FBK

• Optical metrology and 3D reverse engineering techniques for

supporting shipbuilding firms, naval architects and designers ...


OPTICAL METROLOGY FOR MARITIME APPLICATIONS – KEY TOPICS:

- High precision, accuracy and reliability

- Unfavorable environmental conditions

- Need of beaching or docking of the object to

be surveyed

- High costs for shipowners due to docking

operations and derived by the out of service

of the vessel

- GREAT INTEREST IN MEASURING A SHIP

IN FLOATING CONDITIONS !!!

(example: manufacturing parts for damage

repair or ship conversions)

INTRODUCTION


INTRODUCTION

- For semi-submerged still objects an integrated (mobile mapping like) approach is

usually adopted:

Optical methods

Acoustic methods

Above & Under

Waterline

QPS BV

from Handbook of Offshore Surveying

- The drawbacks of these systems:

- Costs

- Availability

- Accuracy and Resolution (for some applications not sufficient)

- Occlusions due to sensors positions


INTRODUCTION

Dry photogrammetry

Underwater photogrammetry

Above & Under

Waterline

- Up to now, there are no methods to survey floating objects in water

AN INNOVATIVE PROCEDURE IS HERE PRESENTED:


3D MODELING OF FLOATING AND SEMI-SUBMERGED OBJECTS

TWO CASE STUDIES

6m long pleasure boat: free floating case

52m long leak at the waterline of Costa Concordia wreck: semi-submerged case


THE PROPOSED METHODOLOGY

ii. the coordinates of one

plate are measured

for example in the

underwater survey

iii. by means of the

measured 4 coded

targets, the OD is

aligned (roto-

translated) in the

underwater reference

system (RS)

iv. the coordinates of the

emerged plate, known

in the underwater

system, are used for

aligning the survey

above the waterline to

the underwater survey

(ii)

(iii)

(iv)

Orientation

Devices (ODs)

are fixed

on the object

i. the 4 coded target

positions on each plate

of the OD are

measured in laboratory


UNDERWATER CALIBRATIONS

Same calibration procedure for dry and underwater calibrations


UNDERWATER CALIBRATIONS

FLAT LENS PORT

DRY

CALIBRATION

UNDERWATER

CALIBRATION

- The focal length is larger for a multiplying factor of 1.34 which is the refractive index

of sea water at 26°C and salinity of 38 g/kg

DOME LENS PORT

DRY UW

Focal Length [mm] 7.31 9.82

DRY UW

Focal Length [mm] 25.58 26.22

- For a dome lens port the refractive effect of water is almost removed!


SURVEY OF THE 52m LEAK OF COSTA CONCORDIA

- PLANNED PHOTOGRAMMETRIC PIPELINE

1. Targeting of the underwater part of the leak

2. Positioning of the ODs to tie the above the

water survey with the underwater survey

3. Positioning of scale bars

4. Taking of Photographs of UW and above

the water parts

5. Semiautomatic orientation and bundle

adjustment of the UW survey based on

circular targets

6. Automatic orientation and bundle

adjustment of the above the water survey

based on natural texture

7. Union of the UW and above the water

surveys

8. Plotting, measurements and analyses


OBJECT TARGETING

• 500 magnetic targets, in white to assure high contrast with the dark red of the ship

• 3 x 2m long galvanized iron SBs (Scale Bars)

• 5 x 3m long galvanized iron ODs

Time required: ca 2h x 4 divers



OBJECT TARGETING

• Targets positioned in a regular grid of side 0.75 m

• Minimum number of target visible in an image: 12

• Targeted area about 5 m x 60 m: 4 m below, 1 m above the sea level




OBJECT TARGETING: TIDE CONSIDERATIONS

• Targets densification across the waterline to take advantage of the tide range

Giglio Island

Tide gauges from Elba island and

Civitavecchia: 25 cm average

range tide in the area of the

shipwreck

semi-diurnal tides (two high waters and two low waters each day)



OBJECT TARGETING


Low Tide

Tide range

Above-water photogrammetric survey carried out during low tide for imaging parts of

the boat and white targets that are submerged during the high tide



OBJECT TARGETING


High Tide

Tide range

Underwater photogrammetric survey carried out during high tide for imaging parts of

the boat and white targets that are emerged during the low tide



UNDERWATER SURVEY

• 4 strips at different depths: -4m, -3m, -2m and -1.5m (from dive computers)

• 80% forward overlap: 50 cm distance between two consecutive shots along strip

• 40% sidelap of ca. between two adjacent strips

• mean distance of 3m from the hull

• during high tide


Moving fishes

following us!!!

…for the

happiness of

automatic

orientation!

Erica Fabio

Mariano

Moving fishes

following us!!!



UNDERWATER SURVEY

• 4 strips at different depths: -4m, -3m, -2m and -1.5m

• 80% forward overlap: 50 cm distance between two consecutive shots along strip

• 40% sidelap of ca. between two adjacent strips

• mean distance of 3m from the hull

• during high tide

CAMERA POSES FOR THE UNDERWATER SURVEY



ABOVE THE WATER SURVEY

• strips at different heights (by using different boats)

• strips at different distances from the ship (7-12 m)

• during low tide Time required: ca 1h (with boat)

CAMERA POSES FOR THE ABOVE THE WATER SURVEY

Distance from the ship

measured

with a laser

distancemeter



Survey parameters Underwater survey

Above water survey

N° of images 580 120

Average distance [m] 3.5 10

GSD [mm] 0.7 1.5

Average intersecting angle [degrees] 72 20

Theoretical precision σX [mm] 1.15 2.06

Theoretical precision σY [mm] 0.79 2.93

Theoretical precision σZ [mm] 1.22 5.32

Relative precision 1:32,000 1:10,000

UP point cloud:

1pt/10 mm

UW point cloud:

1pt/5mm



σX= 7.2 mm

σY= 4.1 mm

σZ= 11.1 mm

Aligned dense point

clouds, reference

system for object

coordinates and

position of the ODs

and SBs.

RIGID TRANSFORMATION RESIDUALS FROM UW to ABOVE WATER RSs



Aligned dense point clouds and camera station positions, reference system for object

coordinates and position of the ODs and SBs.

TO IMPROVE THE ACCURACY OF THE TRANSFORMATION A FURTHER ADJUSTMENT OF 6DOF OF EACH OD, UW AND

ABOVE WATER REFERENCE SYSTEMS WAS PERFORMED USING INDEPENDENT MODEL TRIANGULATION

THE ANALYSIS OF RESULTS IS STILL UNDER INVESTIGATION!



Dimensions of the deformed area, length of principal leak and position of minor cracks

relative to ship’s frame 52

Measurement of 3D coordinates of reference marks welded on the hull surface to perform the 3D

similarity transformation which takes the photogrammetric reference system

to be coincident with the design plane reference system



A: 112 cm

MINOR ISOLATED CRACKS AND LACERATIONS AROUND THE

MAIN LEAK INVOLVING THE DOUBLE BOTTOMS

E: 34 cm

B: 114 cm

C: 15 cm D: 96 cm



Unique point cloud with highlighted cracks and deformations



3D DEFORMATIONS WITH RESPECT TO THE 3D DESIGN PLAN

mm



5 m2 23,6 m2

2,1 m2

23,1 m2

1,3 m2

0,18 m2

𝒇𝒍𝒐𝒘 𝒓𝒂𝒕𝒆 = 𝒌 𝑺 𝟐 𝒈 𝒉

AREA OF LACERATIONS AND INVOLVED COMPARTMENTS

HIGHLIGHTED IN THE DESIGN PLANS



• A new method for surveying floating and semi-submerged objects with high

level of detail (2pts/cm) has been presented.

• The photogrammetric procedure consists of two separate image acquisition

stages, one above the sea level and one underwater. The two surveys are

aligned in a unique reference frame by means of special rigid Orientation

Devices (ODs) measured a priori in laboratory with high accuracy.

• A relative accuracy of 1:4300 using approximated similarity transformation to the

ODs was obtained. By applying an independent model triangulation to the ODs a

1:10000 relative accuracy can be obtained (the worst relative accuracy)

• The proposed photogrammetric methodology is replicable, accurate and

reliable and allowed to derive metric results useful for naval as well as judicial

analyses.

CONCLUSIONS


ACKNOWDLEGMENTS

• A special thank to Mr. Bruno Felleca, Mariano Rovito, Ferdinando Sposito, Dr. Silvio

Del Pizzo and the Italian Coast Guard and Army units for their valuable

collaboration

• Manfrotto, a Vitec Group company, for their kind support

• You all for the kind attention!!!

Bruno

Mariano Ferdinando Silvio

Italian Coast Guard and

Army

The survey of the leak of the “Costa Concordia” Cruise Ship was supported by

the agreement between the Department of Applied Sciences of the Parthenope

University of Naples and the Court of Grosseto


The ISPRS Technical Commission V Symposium will take place in Riva del Garda (Italy) on 23-

25 June, 2014. The Symposium will feature 3 days with plenary and parallel sessions, invited

speakers from research and commercial domains and an exhibition of the most important business

players in the close-range domain. The main topics of the Symposium are:

- Vision metrology and industrial applications

- Cultural Heritage data acquisition and processing

- Terrestrial 3D imaging and sensors

- Algorithms and methods for terrestrial 3D modeling

- Mobile mapping and unmanned vehicle systems for 3D surveying and mapping

Important dates:

- Abstract or full paper submission: March 7th, 2014

- Notifications to the authors: April 25th, 2014

- Final paper submission: May 12th, 2014

ISPRS Technical Commission V Symposium

Photogrammetric Surveying of the Costa...

Documents

Transcript of Photogrammetric Surveying of the Costa...