Weighted Style Photogrammetric Markers

Designed by DeChant Consulting Services (DCS) Inc., Weighted Style Photogrammetric Markers (PM's) assist in measuring features points of interest. Noteworthy in their functionality, the PM's assist in fast and accurate camera orientation in iWitness to quickly image and measure a scene. PM's are used by law enforcement investigators and accident reconstruction practitioners across N. America. The combination of PM's affords very rapid and safe evidence mapping at the scene.

DCS Photogrammetric Markers - bag optional

Below are sample illustrations of the DCS Weighted Style PM's/DM's. The white dots and alpha characters are double sided and concentric.

DCS weighted style RPM for iWitness photogrammetryUn-weighted RPM for iWitness photogrammetry Police Crash Scene Measured with DCS RPMs

On the left: The face and base of an alpha character PM with galvanized weight, which is affixed by special hook & loop Velcro. Center: The new sand bag weighted Dot Marker (DM) - 5 heavy duty, custom made sand bags, are now included with the supplied DM's. On the Right: A crash scene were police investigators mapped the incident with a consumer grade digital camera, the PM's, DM's and iWitness.

The PM's/DM's work well in conjunction with the iWitness target offset feature which enables the 3D point to be automatically projected in the Z-axis up/down direction (e.g., to the ground surface were they are placed.) Optionally, line connected XYZ projected coordinate(s) can then be exported to CAD in the DXF format. The Weighted Style PM's also work excellent in combination with the FMT's and Cone Style Markers.

Storage and Deployment
PM's/DM's are designed to stack in a small container for easy storage in the trunk of a vehicle. There is ‘no fuss’ in access, deployment or storage of the PM's, which are also rugged to support long-term use and weather resistant. The attached galvanized weights and sand bags affords stability in strong and gusting winds.

Specially designed for the iWitness photogrammetry system
The weighted style PM's are made from a 6mm thick closed-cell PVC, with the target dots and A-to-T letter identifiers being of a special Lexan decal material protected with a clear UV blocking agent, making them weather resistant and virtually scratchproof. An additional five "dot markers" (DM's) are supplied, made from 3mm thick plastic and furnished with sand bag weights, provided in the set. The galvanized weights are supplied with a special hook and loop velcro, for the A-T style PM's.

Functionality and Options Available
Using a digital camera and the iWitness software system, the PM's are automatically and accurately marked in the images with 'one mouse click'. From terrestrial imaging, PM's can be used in both daytime and night scene mapping applications. Using the advanced project stitching (3D transformation to control) or the new Project Linking feature available in iWitness, police have proven that PM's work excellent on crash scene mapping projects covering 1000’ (300m) in overall length. The combination of PM's, a moderately priced consumer-grade camera and iWitness, the user is fully equipped and ready for low cost, rapid and accurate 3D photogrammetric scene mapping.

A standard set consists of 20 Weighted PM's (letters A to T) and also a quantity of five dot markers - DM's with supplied sand bags.


Weighted PM's
A quantity of 20 weighted PM's and 5 weighted DM's complete a set. 

Purchasing (domestic):
- PM's are shipped in special packaging anywhere within the USA for $479.00, and shipping.

To order within the USA, use the On line method

Purchasing (international):

- PM's are shipped most places internationally. Contact sales@iwitnessphoto.com for shipping fee information.

Shipments are typically made within 48 hours of receipt of the order.

Inquiries regarding PM's should be forwarded to sales@iwitnessphoto.com.

Delivery Time:
PM's are shipped USPS and arrive to their destination within 3 days (domestic) and typically 12 days for (international) shipping. The customer is emailed with the tracking number for the shipment.

The delivery consists of two boxes with all materials. Minor assembly of the quantity two, pre-cut, adhesive backed and mated Velcro hook & loop to the metal plates are required.

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