Geolocation Accuracy Re-Evaluations of GeoEye-1 and ... · Geolocation Accuracy Re-Evaluations of GeoEye-1 and QuickBird-2 ... Lima, Jorge Chavez, ... Guarani Rio de Janeiro Mar Del

1

Geolocation Accuracy Re-Evaluations of GeoEye-1 and QuickBird-2

Paul C. Bresnahan

Contractor, NGA Image Quality and Utility Program

2012 JACIE Workshop

18 April 2012

1

Approved for Public Release 12-182

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Methodology

• Photogrammetric software provides NIQU/CCAP

capability to use physical sensor or geometry models

with imagery

• Turn photogrammetric software on its head

– “Direct Geopositioning” assessment

– Instead of resecting or triangulating images to ground control

points (GCPs), we fix image support data and allow copy of

GCPs to move to the image or stereo pair

– “Copy of GCPs” are Check Points (CPs)

• End product accuracy assessments

– No correction for off-nadir angle


3

Definitions of Statistics

• Sample Circular Error 90% (CE90) – In horizontal plane

– Radial error distance centered at zero within which 90% of the data points fall

• Sample Linear Error 90% (LE90) – In vertical dimension

– Absolute value error distance from zero within which 90% of the vertical data points fall


4

Methodology

• General Approach:

– Mono CE90: Mono intersection of

mono image or more-nadir stereo mate

to checkpoint (CP) height

– Stereo CE90 and LE90: Stereo

intersection

• Images not allowed to adjust during

evaluation

• Goal of evaluation is to estimate

sample CE90 and LE90 error

statistics for population of stereo

pairs, not individual stereo pair

Monoscopic Intersection

Stereo Intersection

CE90 Only

CE90 & LE90


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GeoEye-1 Basic Product

Evaluation

GeoEye Statements Mono CE90** Stereo CE90 Stereo LE90

GeoEye-1 Specifications (m)* 5 4 6

* Direct geopositioning (no ground control points)

** Excluding terrain effects, and with >60° elevation angle.

Source: http://www.geoeye.com/CorpSite/assets/docs/brochures/GeoEye-1_Fact_Sheet.pdf, accessed 8 February 2012.


http://www.geoeye.com/CorpSite/assets/docs/brochures/GeoEye-1_Fact_Sheet.pdf



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GeoEye-1 25 Basic Stereo Pairs over 24 Test Sites

Stereo Pairs collected from December 2010 to February 2011 and processed from January to February 2011.

From Terminal Aeronautical Global Navigation Satellite System (GNSS) Geodetic Survey (TAGGS) Program

Hosea Kutako

Al Asad

Manas

Silvio Pettirossi

Camp Guernsey

Columbus

Elgin Duke

El Centro

Grand Forks

Kaneohe Bay

Kingsville

Laughlin

March

McConnell

McEntire

Puerto Princesa

Andersen Sale

Viru Viru

Jorge Wilsterman

Chisinau

Jomo Kenyatta

Masirah Island

Thumrait


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GeoEye-1 Sample Mono CE90

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

DN

(m

)

D E (m)

Mono Horizontal Errors (More Off-Nadir Basic Mates)

Mono Error

Mean

CE90 = 3.6 m

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

DN

(m

)

D E (m)

Mono Horizontal Errors (More Near-Nadir Basic Mates)

Mono Error

Mean

CE90 = 2.5 m

Elevation Angles: 57° - 84°

Mean Elevation Angle: 71°

>92.8% confidence that True CE90 < 4.3 m


Mean Elevation Angle: 62°


CE90 = 2.5 m

CE90 = 3.6 m


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GeoEye-1 Sample Stereo CE90 / LE90

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

DN

(m

)

D E (m)

Stereo Pair Horizontal Errors (Basic)

Stereo Pair Error

Mean

CE90 = 2.4 m

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

DH

t. (

m)

Stereo Pair Vertical Errors (Basic)

Stereo Pair Error

Mean

LE90 = 4.1 m

Stereo Convergence Angles: 30°- 40°

>92.8% confidence that True LE90 < 5.3 m >92.8% confidence that True CE90 < 4.0 m

CE90 = 2.4 m

LE90 = 4.1 m


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GeoEye-1 Predicted Stereo Height Errors

Mono Intersection

Stereo Intersection

Truth Point

Mono Intersection DN1 DN2

DH

Stereo Convergence Angle

North

Not to Scale

Descending Direction

Angle eConvergenc Stereo

Errors Northing Mono,

ErrorHeight Stereo

2tan

2

21

12

DD

D

DD

D

C

NN

H

where

C

NN

H


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GeoEye-1 Stereo Mates Northing Errors; Sorted by Abs. Ht. Error

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

DN

(m

)

Stereo Mate Comparison - DN

(Sorted by Absolute Height Error-Ascending to Right)

1st Mates-Delta N

2nd Mates-Delta N


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GeoEye-1 Predicted vs. Assessed Ht. Errors; Sorted by Abs. Ht. Error

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

DH

t (m

)

Stereo Mate Comparison - DHeight

(Sorted by Absolute Height Error-Ascending to Right)

Assessed Height Errors (m)

Predicted Height Errors (m)


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QuickBird-2 Basic 1B Product

Evaluations

DigitalGlobe Statement Mono CE90**

QuickBird-2 Specification (m)* 23


** Excluding terrain effects, and at nadir.

Source: http://www.digitalglobe.com/products#imagery&basic-satellite-imagery, accessed 8 February 2012.


http://www.digitalglobe.com/products





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QuickBird Altitude Change Evaluation 27 Basic 1B Images over 22 Test Sites

Images collected from April to June 2011 and processed from May to July 2011.

Hosea Kutako

Al Asad

Allen

Barking Sands

Cannon

Dyess

Elmendorf

Grand Forks

Henry Post

Laughlin

March

Tinker

Vandenberg

Masirah Island

Bermuda

El Alto

Bucholz Princess Juliana

Jorge Chavez

Rodriguez Ballon

Jose Maria Cordova

Guarani


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QuickBird Altitude Change Evaluation

-25

-20

-15

-10

-5

0

5

10

15

20

25

-25 -20 -15 -10 -5 0 5 10 15 20 25

DN

(m

)

D E (m)

Mono Horizontal Errors

Mono Error

Mean

CE90 = 11.0 m

Off-Nadir Angles: 5° - 19°



CE90 = 11.0 m


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QuickBird Evaluation Over South America 54 Basic 1B Images over 17 South American Test Sites

XX_01

XX_02

Paramaribo

Lima, Jorge Chavez, Las Palmas

Rodriguez Ballon

Guarani

Rio de Janeiro

Mar Del Plata

Ministro Pistarini

Arturo Merino Benitez

Vina Del Mar

Caazapa

Mariscal Estigarribia East

Carlos Ciriani Santa Rosa

Velazco Astete

Images collected from May 2003 to June 2010. 41 images from 2005 onward. Approved for Public Release 12-182

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QuickBird South America Evaluation

0

10

20

30

40

50

60

1/1/2003 1/1/2004 12/31/2004 12/31/2005 12/31/2006 12/31/2007 12/30/2008 12/30/2009 12/30/2010

Dr

(m)

Date (m)

Mono Horizontal Errors

CE90 = 27.7 m (All Images)

CE90 = 17.7 m (From 2005)

Off-Nadir Angles: 1° - 43°


>92.6% confidence that True CE90 < 29.0 m (From 2005) Approved for Public Release 12-182

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Geolocation Accuracy

Monitoring Update

Vendor Specifications GeoEye-1** WorldView-1/2*** IKONOS** QuickBird***

Mono CE90 (m)* 5 5 15 23


** Excluding terrain effects, and with >60° elevation angle.

*** Excluding terrain effects, and at nadir.

Sources: http://www.digitalglobe.com/products#imagery&basic-satellite-imagery, accessed 16 February 2012.

http://www.geoeye.com/CorpSite/products-and-services/imagery-collection/satellite-imagery-products/product-specifications.aspx,

accessed 16 February 2012.







http://www.geoeye.com/CorpSite/products-and-services/imagery-collection/satellite-imagery-products/product-specifications.aspx













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0

1

2

3

4

5

6

7

8

9

10

11

12

Ra

dia

l Err

or

(m)

Worldview-14/1/2010 to 09/30/2011

CE90 = 3.4 m(60 images)

CE90 = 3.3 m(55 images)

CE90 = 4.0 m(19 images)

CE90 = 4.0 m(36 images)

CE90 = 3.0 m(54 images)

CE90 = 3.1 m(35 images)

2nd QtrCY2010

3rd QtrCY2010

4th QtrCY2010

1st QtrCY2011

2nd QtrCY2011

3rd QtrCY2011

Spec.


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0

1

2

3

4

5

6

7

8

9

10

11

12

Ra

dia

l Err

or

(m)

Worldview-210/1/2010 to 09/30/2011

CE90 = 4.5 m(55 images)

CE90 = 4.8 m(38 images)

CE90 = 3.7 m(53 images)

CE90 = 4.8 m(48 images)

4th QtrCY2010

1st QtrCY2011

2nd QtrCY2011

3rd QtrCY2011

Spec.


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0

1

2

3

4

5

6

7

8

9

10

11

12

Ra

dia

l Err

or

(m)

GeoEye-14/1/2010 to 09/30/2011

CE90 = 3.1 m(33 images)

CE90 = 3.2 m(11 images)

CE90 = 2.7 m(11 images)

CE90 = 3.5 m(18 images)

CE90 = 3.8 m(20 images)

CE90 = 3.4 m(17 images)

2nd QtrCY2010

3rd QtrCY2010

4th QtrCY2010

1st QtrCY2011

2nd QtrCY2011

3rd QtrCY2011

Spec.


21

0

2

4

6

8

10

12

14

16

18

Ra

dia

l Err

or

(m)

Ikonos4/1/2010 to 09/30/2011

(5 images)(5 images)CE90 = 15.2 m

(15 images)CE90 = 12.4 m

(14 images)CE90 = 7.2 m(10 images)

CE90 = 13.1 m(11 images)

2nd QtrCY2010

3rd QtrCY2010

4th QtrCY2010

1st QtrCY2011

2nd QtrCY2011

3rd QtrCY2011

Spec.


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0

2

4

6

8

10

12

14

16

18

20

22

24

Ra

dia

l Err

or

(m)

Quickbird4/1/2010 to 09/30/2011

CE90 = 11.8 m(7 images)

CE90 = 16.3 m(37 images)

(3 images) (3 images)

2nd QtrCY2010

3rd QtrCY2010

4th QtrCY2010

1st QtrCY2011

2nd QtrCY2011

3rd QtrCY2011

Spec.


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Summary

• With two minor exceptions, imagery within vendor-stated

geolocation accuracy specifications

– Early QuickBird-2 images over South America

– CY2010 Qtr3 IKONOS: CE90 estimate slightly above

specification but sample size of only 15 images and uncertainty

of estimate straddles the specification line

• Minimal impact for both cases


Documents

Geolocation Accuracy Re-Evaluations of GeoEye-1 and ... · Geolocation Accuracy Re-Evaluations of GeoEye-1 and QuickBird-2 ... Lima, Jorge Chavez, ... Guarani Rio de Janeiro Mar Del