HOEZO DATAKWALITEIT SMART IMAGERY SOLUTIONS

June 26th, 2014

Peter Joosten, CycloMedia Technology B/V.

CYCLOMEDIA: MAIN PRODUCT

360° panoramic images, geometrically correct

Current system: 4800x1200 pixels => 0.075 °, 1.3 cm at 10 meter

Recorded systematically, on a large scale (40.000.000 images per year)

On all public roads, accessible for a small car

- Netherlands: entirely, every year

- Abroad, project based

Unique features:

- Metric accuracy, geo-referenced

- XYZ: 10cm, orientation 0.1 °

0 180 150 120 90 60 30 330 300 270 240 210 180

30

60

90

-30

-60

-90

APPLICATIONS: LOCATION OF OBJECTS

APPLICATIONS: INVENTORY OF TRAFFIC SIGNS

APPLICATIONS: 2D OVERLAYS

APPLICATIONS: 3D OVERLAYS

CONSEQUENTLY => FOCUS: GEOREFERENCING

IMU

GNSS Receiver

RT processor

2x DMI

GPS-Antenna

Multiple camera's

Storage

FROM RAW DATA TO LOCATIONS

Recording Processing Quality control Results

• Pseudo ranges

• Carrier phases

• Doppler

GNSS data

• Accelerations, rotations

IMU data

• Pulses

Wheelsensor data

• Pseudo ranges

• Carrier phases

• Doppler

GNSS Reference data

• Kalman filter

•Testing of observations

•Forward/backward

•Combine

Calculations

• Strange results

• Inconsistencies

Indications

• Manual intervention

• Reject / rework

Solutions

• Location

• Attitude

• Precision

Metadata

• Quality loss?

Coordinate transformation

HOW TO DETERMINE QUALITY OF POSITIONS

Input:

• Quality of input data (observations)

Law of error propagation (3rd party software):

• Assumes only white noise, NO errors

• Assumes realistic quality description of input data

• All parameters effecting quality are taken into account

Result: Can be trusted, only if:

• Correct algorithms are used

• Input data is error free and with realistic quality description

WHAT EFFECTS QUALITY?

(Positioning) quality depends on:

Quality of recording equipment

Quality of processing algorithms

Operator skills

- Driving / processing

Environment!

- Strongly effects

GNSS data

WHAT DO WE KNOW ?

Positioning quality varies strongly,

- Depending on environment

- From excellent to rather poor and erroneous

In urban and forest areas we might expect:

- High standard deviations, caused by

• blocking of satellite signals

- Errors, caused by

• erroneous satellite signals, reflections, etc

- Few satellite signals,

• therefore difficult/impossible to detect errors

WHAT DO WE SEE?

Positioning quality varies depending on environment

- From excellent to rather poor and erroneous

- As expected

3rd party processing software is rather optimistic about quality

(Note: This holds for all manufacturers we investigated)

- Reasons for this:

• not taking into account: Residual influences of atmospheric delays

• not taking into account: Optimistic assumptions for quality of raw data

(own + reference stations)

• not taking into account: Errors in observations (when impossible to detect)

• They have to sell, need to be better than the competition

WHAT DO WE DO ABOUT IT

Provide quality information per image

When doing measurements, use a lower bound for the precision of cyclorama

“CycloPositioner”

- Add image data to the positioning process

- Perform (photogrammetric) bundle adjustment

- This reduces and removes the effect of errors

- Improves the actual locations to match better with the standard deviations

Provide options to users to verify (relative) locations in GlobeSpotter

- Reliability calculation

PROVIDE INFORMATION TO CUSTOMERS

RESULTS: WASHINGTON (BEFORE)

RESULTS: WASHINGTON (AFTER)

WHAT CAN/SHOULD YOU DO AS A USER

Use images from different

streets

- Implies different times

- Implies no correlation

Reliability “green”

- Implies mathematical

model is internally

consistent

- Implies standard

deviations are reliable

Q & A

WETEN WAT JE KRIJGT

Uit “van Dale”, EN-NE, “Pitch”:

worp: (figuurlijk) make a pitch for sth. een gooi naar iets doen

hoogte, intensiteit, top(punt), (muziek) toon(hoogte): perfect pitch absoluut gehoor

(Brits; sport) (sport)terrein, veld, (cricket) grasmat

(slim) verkoopverhaal, verkooppraat(je)

standplaats, stalletje, stek

schuinte, (dak)helling

pek