Naval Research Laboratory, Code 3220, 4555 Overlook Ave. S.W., Washington, D.C. 20375-5326

66 -- SURROUND PROJECTOR SCREENING SYSTEM SOL N00173-00-R-MS07/0002 DUE 082800 POC Mary Sandy, Contract Specialist, Code 3220.MS, F. Janilea Bays, Contracting Officer, (202) 767-3710 E-MAIL: click here, sandy@contracts.nrl.navy.mil. This notification is in response to questions that were received regarding the previous synopsis that appeared in the July 20, 2000 edition of the Commerce Business Daily. The following are the stated questions with the answers to each question: Question 1: How may outlets are needed for the system, in regards to telephone or data cabling or the footage on the average runs? Answer 1: The area for the system is 18 X 20 foot with a total of 16 available outlets (115 volts, 20 amp) distributed along three walls. This system does not require any telephone cabling. The type of cables used to connect the cameras can be determined by the offeror based on the requirement as originally synopsized. Question 2: Since this is a digital camera, please clarify how many bits per pixel that are necessary to meet the Government's requirement at 120Hz. Answer 2: The Government does not have a minimum bit per pixel requirement. Different technical approaches may suggest different bits per pixel. All other things being equal, a higher bits per pixel camera is preferred. Question 3: The required resolution at 120Hz is 1000x1000. What is the minimum required resolution at 60Hz? Answer 3: The minimum resolution required at 60Hz should be considered to be 1000x1000. Question 4: It appears these specifications are based on the proprietary camera belonging to a single esteemed motion capture supplier. Since the solicitation is open to general participation, is it safe to assume that the Government will also approve of other commercially available digital camera technology as long as total system accuracy and frames per second meet the Government's requirements? Answer: 4 The Government will review and consider all submitted proposals. In addition to the specific requirements listed, concerns with any optical tracking system include: how well and consistently can the system tell one marker from another, how accurately does the system perform when a marker is partially occluded, and how quickly can the system reacquire an occluded marker once it becomes visible. Exact metrics (or requirements) for these factors can not be defined as they will vary with system use. Tracking at 120 Hz (double the required data output rate) facilitates the labeling of markers due to trajectory coherence. High resolution cameras combined with small physical markers reduce marker occlusion and marker co-alignment difficulties (i.e. reduces marker labeling and positioning errors due to these effects).Question 5: . The requirement " expandable to 24 cameras with the addition of 14 cameras and associated cabling and connectors. (i.e., no additional processing hardware required)" also appears to be based on a single vendor's specification. Would the Government reconsider this to allow for more general participation? Rather than specifying the max number of cameras, please do consider requiring "The system must be expandable to any number of cameras" Answer 5: A geometric analysis of our lab space (defined in requirement number 3, lab dimensions) and where we are most likely to want to apply markers to a human subject (defined in requirement 1, full-body) suggested that a 12 camera system would be close to ideal (in a 6 up and 6 down configuration). However, our analysis showed that a ten camera system would provide adequate coverage and thus is our minimum requirement. We have a future requirement to track a second human subject, also full-body, in another part of our lab space. Rather than hamper ourselves in a future we can not predict with 100% accuracy, we have made the future requirement be for a minimum of 24 cameras. All other things being equal, a system that can expand beyond 24 cameras will be considered. Question 6: From 15, our understanding is that the motion capture system must according to the Government's specification, output 60 3D coordinates per marker per second within accuracy as specified in " 2. Sub-millimeter accuracy and precision is required for the generated 3D positional data." and with a latency of no more than 55ms. Is our understanding correct? Answer 6: That is part of the output requirement for real time tracking. See also "requirement 1. ...positions and joint angles ..." and "requirement 14. The system must reconstruct ...". The markers will be attached to a human and the system must output body part joint angles in addition to marker position, in real time. Question 7: For clarification, assume two groups, both groups pointing in different directions. The static calibration object used for establishing axes direction is visible from all cameras in Group 1 while calibrated with the dynamic calibration object. Which of the following is the Government's intention? Number 1: After Group 1 is calibrated, the static object is moved to Group 2 and the dynamic calibration process is repeated. Number 2: Group 2 is only calibrated with the dynamic object. Answer 7: Number 1 is the government's intention. Posted 08/16/00 (W-SN486834). (0229)

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