Document ID: chunk:federal_register_of_legislation:F2024C00147:body:0:p45
Version: federal_register_of_legislation:F2024C00147
Segment Type: other
Provision Reference: 
Character Range: 157388–160542

Figure 2
       Typical relationship between the size of the triangle and the fraction of correct responses.

       1.2. Determination of the critical viewing distance of the monitor

        For a monitor having certain dimensions and properties, the distance to the monitor can be calculated within which the detection distance is dependent only on the performances of the camera. The critical viewing distance rmcrit is defined as the distance at which the smallest discernable detail displayed on the monitor spans 1 arcmin measured from the eye (the acuity threshold of a standard observer).

       Where:
       rmcrit : critical viewing distance of the monitor (m)

       δ : size of the smallest discernable detail on the monitor (m)

       1.3. Determination of the detection distance

       1.3.1.  Maximum detection distance within the critical viewing distance where, due to the installation, the distance eye-monitor is less than the critical viewing distance, the maximum attainable detection distance is defined as:

        Where:

       rdclose: detection distance (m)

       D0 :  diameter of the critical object (m) according to paragraph 2.1.2.6. of this Regulation; for the calculation of rdclose for class V and VI devices, a representative value of 0.30 m shall be used

        f:  threshold increasing factor, which is equal to 8

        ωc:  smallest discernable detail (arcmin)

       1.3.2. Detection distance greater than the critical viewing distance. Where, due to the installation, the distance eye-monitor is more than the critical viewing distance, the maximum obtainable detection distance is defined as:

         (m)

        Where:

       rdfar: detection distance for distances larger than the critical viewing distance (m)

       rdclose:  detection distance for distances smaller than the critical viewing
       distance (m)

        rm: viewing distance, i.e. distance between eye and monitor (m)

        rmcrit: critical viewing distance (m)

       2. Secondary functional requirements

        Based on the installation conditions, a determination shall be made to discover whether the entire device can still satisfy the functional requirements listed in paragraph 6.2.2. of this Regulation, especially the glare correction, the maximum and the minimum luminance of the monitor. It shall also be determined the degree to which the glare correction will be addressed and the angle at which sunlight can strike a monitor and these shall be compared to the corresponding measuring results from the system measurements. This can be either based on a CAD-generated model, a determination of the angles of light for the device when mounted on the relevant vehicle, or by carrying out relevant measurements on the relevant vehicle as described in paragraph 6.2.2.2. of this Regulation.

Annex 11

Determination of the displayed object size

       1.  Camera monitor device for indirect vision

       1.1.  General

       Determination of the displayed object size considers the possible appearance of smear. The impact on the monitors image and consequence is the occultation of the field of view