Graphics Reference
In-Depth Information
lens is that the distance between two Airy disks' centers is greater than the radius of
each Airy disk, which is the famous Rayleigh's law [11].
Theory of human eyes' receptors holds the viewpoint that when object points are
sensible to a single receptor, there must be at least one receptor not stimulated by light
between the two receptors, on which two object points' images cast separately, so as
to ensure the two points are distinguishable on image. There are strong reasons behind
this judgment: when image spots of two object points cast on two neighboring recep-
tors, the system is unable to tell this situation from another one that an unique object
point's image spot casts right on the boundary of the two receptors, which results in
image the same as the previous situation.
Considering all described above, we define two object points distinguishable to
HIS when they satisfy both following criteria.
Criterion of wave optics: The distance between centers of the two object points'
image spot is not less than the larger radius of the two Airy disks.
Criterion of receptors: There is at least one un-stimulated receptor between the two
receptors on which the two object points' image spots separately cast.
We define the ARP of HIS as the minimum angle of two object points relative to
optical center of HIS when they are distinguishable and right satisfy one of the crite-
rion: the distance between centers of the two object points' image spot is equal to the
larger radius of the two Airy disks, or there is only one un-stimulated receptor be-
tween the two receptors where the two object points' image spots rest. By each of the
criteria, two ARPs can be achieved and, naturally, we select the larger one as the
actual ARP for HIS.
S
t
d
O
S
Z
ˈ
O
X
L
Fig. 2. Coordinator for observation of HIS
3.2
Calculation of ARP for HIS
Given object points' azimuth and speeds, parameters and principles of work of HIS
(Fig.2 and Fig.3), two ARPs by both criteria are achieved. If positions and deflections
of the points are available, the minimum distinguishable distance (MDD) of the points
is also calculable and thus the threshold for distinguishability is established.
 
Search WWH ::




Custom Search