qualification of pleiades stereo pairs · emergency : damage assessment (floodings, forest fires,...

J.Ph. Cantou (IGN France) : Qualification of Pleiades stereo pairs for BD Topo® data capture and update ign.fr


Qualification of Pleiades stereo pairs for BD Topo® data capture and update

01. The Pleiades satellite system02. Assessment of Pleiades stereo pairs for topographic mapping03. Perspectives for Pleiades operational use at IGN France

J.Ph. Cantou (IGN France) : Qualification of Pleiades stereo pairs for BD Topo® data capture and update

01. THE PLEIADES SATELLITE SYSTEM

3/


01. THE PLEIADES SATELLITE SYSTEM

2 agile satellites placed on the same orbit :

Pleiades 1A launched end 2011, operational since june 2012

Pleiades 1B launched end 2012, operational since feb 2013

Image acquisition :

Heliosynchronous orbit => 10h30 UT time

North-South strips acquired with 20 km swath (300 km maximum length)

Very high on board storage capacity (up to 600 scenes per day per satellite)

Products :

B&W, R,G,B,NIR – GSD 50 cm after processing

Stereo & tri stereo

Mosaics


Within 13 days, all orbits are flown either by Pleiades 1A or Pleiades 1B

13 days cycle

Pleiades 1APleiades 1B


Every day access to any spot above 50°

latitude with 30°

maximum viewing angle

Pléiades 1A Pléiades 1BPléiades 1APléiades 1B


EUROPE : available catalogue at August 25th, 2013

https://geostore.astrium-geo.com/en-EMEA/449-pleiades-coverageMise à jour du 19/02/2013 – PLEIADES 1A et 1B

Scenes with clouds < 10%

https://geostore.astrium-geo.com/en-EMEA/449-pleiades-coverage


© CNES Distribution Astrium services

R‐G‐B

NIR‐R‐G

50 cm GSD

The atlantic ocean shore near Bordeaux



Clearcuts in the Landes forest (south west France)

J.Ph. Cantou (IGN France) : Qualification of Pleiades stereo pairs for BD Topo® data capture and update ign.fraerial BD Ortho®

‐

2011 Pleiades

Ortho

–

24th

April

2013


The Strasbourg city centre


02. ASSESSMENT OF PLEIADES IMAGES FOR TOPOGRAPHIC MAPPING AT IGN IGNSYSTEM

11/


02. POTENTIAL USE OF PLEIADES AT IGN

AS A COMPLEMENTARY SOURCE TO AERIAL PHOTOGRAPHY

Orthoimage (BD Ortho®) : speed up the frequency of observation

Orthoimage (BD Ortho®) : save flight hours over mountainous areas

AS A SUBSTITUTE TO AERIAL PHOTOGRAPHY

Emergency : damage assessment (floodings, forest fires, storms, land slides,…)

2D classification of forest species (BD Forêt®)

3D geographic database (BD Topo®) updating : stereo capture of features in vector mode

Height measurement : DTM generation

Change detection, mainly by comparison DEM / DEM


Aerial programmeAerial programme27 districts27 districts

acquired at 25 cm GSDacquired at 25 cm GSD

Coverage : 180 000 km2Coverage : 180 000 km2

France’s 2012 national image coverage programme

Coverage : 15 000 km2Coverage : 15 000 km2

Mainland:LozLozèèrereHautesHautes‐‐AlpesAlpesMontMont‐‐Blanc Blanc

(stereo)(stereo)

Overseas :StSt‐‐Pierre et Miquelon Pierre et Miquelon

(stereo)(stereo)MartiniqueMartiniqueGuyane (partly)Guyane (partly)


SUMMER 2012 : 6000 KM2 HAUTES-ALPES COVERED WITHIN 2 MONTHS

Specifications :angles < 10°cloudfree


BD Ortho® : are hybrid orthoimage (aerial / satellite)feasible and acceptable over mountainous areas ?


BD Ortho® : hybrid orthoimage over mountains

Purpose : generate aerial / Pleiades orthomosaics

Test area : Mont-Blanc (the French Alps)

Image data acquired in good conditionsPleiades 50cm: 19th august / angle < 10°Aerial 25cm : 8-11 august / good homogeneity

Results :

the seam line is geometrically non visible

radiometric balance is acceptable

general rendering is correct


Results

BD Ortho® : Hybrid orthoimage over mountains


POTENTIAL USE OF PLEIADES AT IGN



Orthoimage (BD Ortho®) : save costly flight hours over high mountains



2D classification of forest species (BD Forêt)

3D geographic database (BD Topo®) updating : stereo capture of features in vector mode




POTENTIAL USE OF PLEIADES AT IGN



Orthoimage (BD Ortho®) : save costly flight hours over high mountains



2D classification of forest species (BD Forest)

3D geographic database (BD Topo®) updating : stereo capture of network and built up features




St‐Pierre‐et‐Miquelon Pleiades stereopair May 1st 2012

BD Topo® : are retrieved 3D vector data from Pleiades stereo compliant with data base specifications ?



Railway NANCY-STRASBOURG

"ribbon" of 100 km x 5 km to be acquired in stereoscopy

5 Pleiades stereo pairs obtained at 4 dates in 2012 and 2013

22/

BD Topo® updating along a High Speed Railway under construction

J.Ph. Cantou (IGN France) : Qualification of Pleiades stereo pairs for BD Topo® data capture and update 23/



Control points



Processing and data capture from IGN’s GEOVIEW® software

Pleiades stereo pairs : B/H ratio from 1.3 to 2

Features retrieved in 3D : railway axis, secondary network, hydrography

Results:

Processing duration correct

XYZ accuracy assessed against ground control and geodetic points : better than one meter, matching BD Topo® specifications

Visual comfort is suitable, with slight preference for colour to B&W

Drawback : no possibility to see the objets from several angles of view

Advantage : a large coverage (up to 20x21 km) which reduces switches between several pairs

Vectors obtained have been integrated into the BD Topo® data base

27/06/2013 25/


J.Ph. Cantou (IGN France) : Qualification of Pleiades stereo pairs for BD Topo® data capture and update/ 34 26/

Purpose of the study

Generate DTM in montainous area where existing BD Alti® data base is less accurate

Test area Corsica (Bavella) :

3 pairs were acquired on the same area :

2 with 20° roll angle but with 26 days interval

One with low roll angle later

Methodology

Geometric modelling of images

DSM production

Transformation DSM => DTM (existing production line)

Comparison with :

BD ALTI® accuracy > 6 m

INTERMAP (radar data) accuracy about 7 m

Qualified points xyz (geodetic, networks) submetric accuracy

Ground height retrieving by DTM generation


Visual rendering



Pleiades results are better than existing BD ALTI® and aerial radar

27/06/2013 28/



03. PERSPECTIVES FOR PLEIADES OPERATIONAL USE AT IGN FRANCE

29/


Progressively update the orthoimage coverage of French Guyana


GUADELOUPE : 2035 KM2

30/01/13(Angles 6,8° et

11,8°)

16/01/13(Angles 20° et

17,1°)

23/03/13(Angles 6° et 10,7°)

02/06/13(Angles 118° et

8,1°)

30/01/13(Angles 11,5° et

9,2°)

11/04/13(Angles 11,4° et

7,9°)

11/02/13(Angles 13,8° et

15,7°)

Cover overseas regions in stereoscopy a programme was launched early 2013 over the French West Indies

16/03/13(Angles 13,2° et 13,7°

08/05/13(Angles 11,9° et 11°)

11/03/13(Angles 14,1° et 13,1°

02/05/13(Angles 15,3° et 14,6°

03/03/13(Angles 16,4° et 15,7°

29/03/13(Angles 14,9° et 14,2°

MARTINIQUE : 1895 KM2


Monoscopy Stereoscopy

Tasked Covered Geocoded

Assess Pleiades coverage capacity over the mainland in 2013

Tasked Covered Geocoded

status at mid August


PLEIADES AT IGN : PERSPECTIVES FOR 2014

33/

Main technical issues are now under control

Other studies to be explored : forest mapping and monitoring

Towards a IGN’s multi year image coverage programme ? the strategy « Pleiades vs airborne » is presently worked

out, taking into account economic and operational aspects

2014 event :

« Pleiades days » in Toulouse 1-3 April 2014


Pleiades image distribution to French public bodies : IGN will be the national focal point

CNESCNES

Astrium / Spot ImageAstrium / Spot Image

IGNtechnical and contractual support to public bodies

IGNtechnical and contractual support to public bodies

Public services and authorities

Public services and authorities

Coverage

requirements

Academic usersAcademic users

Geocodingdownload facility

archiving

Image taskingValidationPurchase

User requests

filteringTasking

programme optimizing

Monitoring public service delegation

www.ign.frwww.astrium‐geo.frwww.cnes.fr

http://www.ign.fr

http://www.astrium-geo.fr

http://www.cnes.fr

qualification of pleiades stereo pairs · emergency : damage assessment (floodings, forest fires,...

Documents