VisionMap A3 - Host Ireland

VisionMap A3 

Super Wide Angle Mapping System 

Michael Pechatnikov, Yaron Vilan, Yuri Raizman 

VisionMap Ltd. 

10.07.2008 

Proprietary VisionMap Information

Consider this project… 

• Spec 

– 15cm orthophoto 

– 20,000 km^2 

– Maximum of 20 degrees off nadir for orthophoto 

• This would require 

– 12 successful days of 

regular large frame cameras 

– 5 successful days of A3 

• What makes it possible? 


Oblique imagery 

Proprietary VisionMap Information 

Slant distance: 9,000 m 

60° off-nadir

Oblique imagery 


Altitude: 3,500 m 

45° off-nadir

Vertical imagery 


Flight altitude: 3,600 m 

GSD: 10.8 cm

A3 - Light weight camera 

• Computer: 

Weight – 10 kg; 

Size - 25*40*40 cm; 

• Camera: 

Weight – 15 kg; 

Size - 50*50*40 cm; 

• Installation time – 15-30 min; 

• No need in special airport 

transportation; 


A3 camera design 

• Digital sweep-framing double lens 

metric camera; 

• Cross-track sweep motion; 

• Focal lens – 300 mm; 

• Folded optics; 

• Maximal sweep FOV–104 degree; 

• FMC, SMC, Vibration - mirror 

based optical compensation and 

stabilization; 

•Weight –15 kg; 

•Size –50*50*40 cm. 


Flight direction

Super large frames 

• Smooth sweep 

movement; 

• 27 double frames 

per sweep; 

• Along strip overlap 

between frames 2%; 

• Cross strip overlap 

between frames 

15%; 

• An overlap between 

two sweeps – 56%. 

Single Frame 

Lenses 

Sweep 

Movement 

Super Large 

Frame – 480 Mpix 


Flight 

Direction 

Double Frame

SLF – super large frame 


A3 on-board computer 

• Intel based computer; 

• On-board J2K compression; 

• Dual frequency GPS (Omni Star supported); 

• Internal power supply; 

• Snap-on 0.5 TB solid state flash storage; 

• Weight – 10 kg; 

• Size – 25*40*40 cm. 


3 km 

1 km 

Why altitude matters 

Assuming angle 

off nadir < 15° 

0.5 km 


Super large 

frame – A3 

Large frame 

digital cameras

Applied to “our” project 


Ensuring accuracy & robustness 

Multiple images 

Multiple directions 

90-100° angles 

X00,000 tie-points 


Bundle adjustment 

No IMU 

No control points 

Blocks of 700,000 frames 

have been solved 

x,000,000 tie points, each 

With multiple intersections 

and wide angles 

Fully automated process 

Tools to validate 


Aerial triangulation accuracy 

• Flight altitude – 12,000 ft; 

• Area – 2,680 sq.km; 

• Single images – 250,000; 

• Ground resolution – 12.5 cm; 

• No Ground Control Points. 

Check 

Points 

P1 

P2 

P3 

P4 

P5 

P6 

P7 

P8 

P9 

P10 

P11 

AVG 

RMS 


Dx 

-0.20 

0.10 

-0.19 

-0.17 

0.43 

-0.13 

-0.03 

-0.14 

-0.12 

0.07 

-0.14 

-0.05 

0.18 

Dy 

0.02 

-0.04 

0.07 

-0.09 

0.04 

-0.24 

-0.03 

0.05 

-0.15 

-0.28 

-0.11 

-0.07 

0.13 

Dxy 

0.20 

0.11 

0.20 

0.19 

0.43 

0.27 

0.04 

0.14 

0.20 

0.29 

0.18 

0.20 

0.23 

Dz 

-0.06 

0.11 

-0.09 

-0.16 

0.74 

-0.44 

-0.20 

-0.17 

-0.30 

-0.21 

-0.13 

-0.08 

0.30

Automatic mosaicing 


Orthophoto angle map 

• Dark blue represents Nadir 

• Geographical representation 

• Provides color cueing for 

areas requiring attention 


Radiometry correction map 

• Geographical 

representation of areas 

processed by the 

radiometry correction 

stage. 

• Maps the change (in grey 

levels) per pixel. 

• Points to areas requiring 

attention 


Conclusion 

• High efficiency – for a given resolution, throughput in sq. km 

per hour is substantially better than with other systems; 

• A single flight yields an Orthophoto and photogrammetricaly 

solved multi-directional Oblique and Vertical images; 

• Super Large Format images for stereo mapping; 

• The 300mm focal length enables operation at High Altitudes 

(which is crucial in urban areas); 

• Light weight, small size and simple installation; 

• Total automation of all processes; 

• High photogrammetric accuracy and process stability; 

• Virtually unlimited number of images; 

• No preliminary DTM, No Ground Control, No IMU are 

required; 


Thanks for listening! 

We’ll be glad to answer you questions (: 


Technical characteristics 

CCD (dual) 

Single Frame 

Double Frame 

Double Frames 

per sweep 

Synthetic Super 

Large Frame 

Single Lens FOV 

Max.Sweep FOV 

Aperture 

KAI-11002 

4006*2666 pix 

7812*2666 pix 

27 

62,517*7812 

~480 Mpix 

6.9*4.6 degree 

13*104 degree 

f/4.5 


Color 

Bit per 

Channel 

Pixel size 

Frame rate 

Read out rate 

Data 

collection 

capacity 

Total weight 

Operating 

temperature 

RGB 

12 bit 

9.0 µm 

7 fps 

155 MB/sec 

5-8 hours 

27 kg 

-30° to 45°

SLF – Super Large Frame 

Flight Altitude (m) 

Flight Altitude (ft) 

SLF’ Short Side (m) 

SLF’ Long Side (Swath) (m) 

SLF’ Area (sq.km) 

Sweep Stereo Area, 56%, (sq.km) 

Strip Stereo Area, 50%, (sq.km) 

Base Ratio between Sweeps (B/Z) 

Base Ratio between Strips (B/Z) 

Nadir GSD (m) 

Oblique GSD (m) 

1,500 

4,921* 

354 

1,435* 

0.5 

0.3* 

1:7.6 

1:0.8 

0.05 

0.08 


5.4 

1:7.6 

1:0.8 

0.10 

0.16 

10.7 

1:7.6 

1:0.8 

0.14 

0.23 

34.0 

17.0 

1:7.6 

1:0.8 

0.25 

0.41 

* In order to maintain the Sweep overlap, in altitudes lower than 9000 ft, 

the angular coverage is decreased. 

0.7 

3,000 

9,842 

709 

7,679 

3.0 

2.7 

4,200 

13,779 

992 

10,751 

6.0 

5.3 

7,500 

24,606 

1,772 

19,198 

19.1

Preliminary Accuracy Analysis 

P1 

L 

∆x 

= 

∆y 

= 

∆z 

= 

B 

Q 

2 f cosα 

l 

a 

α 

2 f 

l 

l 

2 f sinα 

H 

P2 

A scheme for accuracy analysis 

Formulas for accuracy analysis 

Photo Scale 

5,000 

10,000 

14,000 

25,000 

5,000 

10,000 

14,000 

25,000 


σx 

0.01 

0.02 

0.03 

0.05 

0.01 

0.03 

0.04 

0.07 

σy 

0.01 

0.02 

0.03 

0.05 

Base-ratio 1:0.8 between Strips (α=32.6°) 

0.01 

0.03 

0.04 

0.06 

A3 

σxy 

0.02 

0.03 

0.04 

0.08 

0.02 

0.04 

0.05 

0.10 

ASPRS 

Class 1 

σxy 

Base-ratio 1:7.6 between Sweeps (α=3.8°) 

0.063 

0.31 

0.63 

1.25 

0.063 

0.31 

0.63 

1.25

ASPRS Accuracy Compliance 

Contour 

Interval 

Class 1 

Class 2 

Class 3 

Class 1 

Class 2 

Class 3 

H 

1000 

1100 

1250 

strip 

0.02 

0.02 

0.02 

0.5 

σz 

ASPRS Elevation Accuracy requirements 

0.08 

0.16 

0.25 

VisionMap A3 Elevation Accuracy estimations 

sweep 

0.11 

0.12 

0.13 

H 

2000 

2200 

2500 

σz (for overlaps: strip – 50%, sweep – 56%) 

strip 

0.03 

0.03 

0.04 

1.0 

σz 

0.17 

0.33 

0.50 

sweep 

0.21 

0.24 

0.27 

H 

4000 

4400 

5000 

strip 

0.06 

0.07 

0.08 

2.0 

σz 

0.33 

0.67 

1.00 

sweep 

0.43 

0.47 

0.54 


H 

5000 

5500 

6250 

strip 

0.08 

0.09 

0.10 

2.5 

σz 

0.38 

0.75 

1.25 

sweep 

0.54 

0.59 

0.67 

H 

8000 

8800 

10000 

strip 

0.12 

0.14 

0.16 

5.0 

σz 

0.67 

1.33 

2.00 

sweep 

0.86 

0.94 

1.07

VisionMap A3 - Host Ireland

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