PHOTOGRAMMETRY

New Ideas in Scene Diagramming

What Photogrammetry is about.

PhotogrammetryPhoto = Recording LightGrammetry = Measure

○ Measurement using photographs.

BenefitsHighly AccuratePreserves the scene at the time the photos

were takenGets the investigator out of harms way

quicker

What Photogrammetry is about.

DownfallsExtra training is required to complete the

diagram

Instead of time spent at the scene measuring, the time is spent at the computer mouse clicking.

What Photogrammetry is about

Has been proven to open/clear scenes quicker allowing traffic to clear in less time.

Less traffic backups mean less secondary collisions.

This is the Basis for IN-TIMEIndiana-Traffic Incident Management Effort.

Since June 20th , 2009. Indiana has used Photogrammetry 29 times.

27 uses involve roadway closings 6 crime scenes have been measured

42 minutes is the average time it takes to measure a scene using Photogrammetry.

2 Hours and 13 minutes is the average times to use total station to measure a scene. (estimated)

Means: 1 hour and 31 minutes saved. If it takes 4 minutes to resume normal traffic –

around 9868 minutes would be save to Indiana Motorists. 1:31 = 91 Min * 27 scenes = 9868 minutes saved.

What Photogrammetry is NOT

Voo Doo Science New

1) Ideas have been around for quite a while2) Principles have been proven under Fry

and Daubert Not the old “Vanishing Point” Method

We are in the computer age. Not Photo rectification or Flattening an

Image to diagram.

Compared to other measurement systems.

Tape Measure Photogrammetry Laser

3

0.5

3

3

3

0.5

Systems of Measurement

At Scene After Scene

Compared to other measurement systems.

Tape Photogrammetry Laser$0

$1,000

$2,000

$3,000

$4,000

$5,000

$6,000

$7,000

$8,000

Costs

Costs

What you need for Photogrammetry Camera Tripod Memory Cards Targets iWitness Software CAD-software (Crashzone recommended) Tape Measure For more advanced – Smart level Flashlight

Camera

More than a 6.1 MP cameraIndiana State Police uses a 10 MP Olympus

Camera Requirements Must be able to turn off Auto FocusMust have a Manual Mode

Chip size does make a differencePoint and Shoot vs D-SLR.Relates to night scene quality and overall

image quality.

Cameras

Point and Shoot vs Digital-SLR (DSLR) Think of sensor size and quality, bigger sensor – better quality

Camera

I have tested….Nikon D90,D70, D100, D700, D3Canon 1d II, 5D, 5D II, G9 (P&S)Sony Olympus E-420, E-520Nikon Point and Shoots: sj1000pj

Tripods

Hold the camera steady for night and low light shooting.

Any will workMake sure the specks say they will hold the

cameras weight.

Memory cards.

Hold the images taken at the scene. Anyone will work

Weighted and Cone Targets

Cad Software

Tape measure

Needed to measure 2 scale distances

iWitness Photogrammetry Software

MS Windows base software for measuring and modeling OBJECTS or SCENES.

Uses digital images to mark (X,Y,Z) coordinates for use in CAD software to diagram scene.

iWitness Photogrammetry

YOU do not have to know the MATH involved in determining these points.

YOU only have to know how to see the point, photograph the point, and click a mouse in various images.

Photographing the Scene Pictures must have good angles

between each other The same point must be photographed

using different angles. Look at the cones in the next slide…

Same cones, different angles…

Photographing the Scene

Nuts and Bolts of Photogrammetry Cameras see 2D images in a 3D world.

Nuts to Bolts (Cont)

Photogrammetry brings back the 3D world out of 2D images

Images MUST be taken in a certain way then

This is a simplified way to think of photogrammetry. This is not the math utilized in iWitness or an attempt to show the math in the program.

Photos of Same object from different angles.

These two lines are the same line in different photos.

These lines are REFERENCED to the same markers we have placed in the scene in different

photos.

What do Angles have to do with it? A camera can only see 2 dimensions With the same point referenced in

different pictures, shot at different angles the computer can do a “triangulation” to get the EXACT point in 3d space.

Angles

Camera Camera

The Scene…..

Photographing the Scene using Angles.

Did I mention Angles?

Taking the photos

Left side of the road Right side of the road

Crashzone Work

Timeline (Rounded)

Arrive at scene - 3:00 pm Walk and investigate scene Start Photos - 3:22 pm Finish Photos - 4:02 pm Release scene to Wrecker Wrecker off Scene – 4:32 pm Time Road Closed – about 1.5 hours.

Above using ISP stats since June 20th 2009.

Remember

There is still work to be done doing the diagram away from the scene.

○ Officer is safer- Paper Cut vs Run Over- Climate Controled- Stress free

○ Roadway is opened and flowing sooner○ Less Secondary Collisions!!!!!

Photogrammetry Questions

HOW ACCURATE Depends on the number of photos taken Accuracy under MY CRASH SCENES

Most Accurate 1/8” over 1000 feet Least Accurate 1 Inch over 500 feet

○ 2nd scene before actually being trained in its use

Crime Scene

Crime Scene

Crime Scene

I was sent 8 Photos of the scene

Camera was not calibrated and the Camera was auto-focusing.

Measurement Reported to me was 50 Inches.

Reasons for .3390 of an INCH - Round Error?

Another Case Study..

November 27th, 2008 at 11:30 PM.I-65 NB at 241 MM, 1 Vehicle Fatal Crash

Northbound vehicle loses control and goes into the median. Flips end over end and comes to rest against SB guard rail.

2 occupants ejected; one in median and one on SB traffic side.

Another Case Study..

November 27th, 2008 at 11:30 PM.Roadway closed for approximately 1 hour.

The at scene trooper painted the roadway to mark scene

Reconstructionist did not go to scene that night as I was more than an hour away.

Another Case Study..

November 28th, 2008 at 11:30 AM.Went to the scene to measure

Took approximately 1 hour to photograph the scene as the family arrived on scene for an explanation of the crash.

Time the roadway was closed to measure scene...

Another Case Study..

November 28th, 2008 at 11:30 PM.IT WAS NOT!!!!! NO CLOSURE.

The following diagram was completed.

Scale Diagram of Scene

IN 3D – Using Crashzone

Corners of Highway sign

Costs…..

Camera – Around $500.00 + Calibration Targets – $89.00 Tripod – Around $50.00 Memory Cards – $20.00 Targets – $450 to 610.00 iWitness Software – $995.00 to $1995.00 CAD-software (Crashzone) – $695.00 Tape Measure – $10.00 For more advanced – Smart level – $45.00 Flashlight – $50.00 Total = $3064.00 as listed

websites…..

Camera – Various Calibration Targets – www.iwitnessphoto.com Tripod – Various – Amazon, etc Memory Cards – Camera Stores etc. Targets – www.iwitnessphoto.com iWitness Software – www.iwitnessphoto.com Crashzone – www.cadzone.com Tape Measure – Home Depot, Menards, etc For more advanced – Home Depot etc. Flashlight – anywhere to issue.

www.iwitnessphoto.com○ Lee DeChant Consulting Inc.○ Sole Source in North America○ iWitness Software, targets

www.cadzone.com○ Anna Ristau is Law Enforcement Contact○ Crash/Crimezone

S/Trp Thomas W Quinn○ Indiana State Police○ 219.405.5507

Finally……

All of this software requires training. Indiana has 6 trainers in

photogrammetry○ 5 ISP Troopers○ 1 Boone County Deputy