OK, but my point is that the variations should affect only the depth of view, not the width - which is what I'm concerned with as far as preventing overlap of the sensors.
Bogus.
You continue to make the same wrong assumptions when it has been clearly explained by multiple people. Why would the width of field NOT be effected?
My fun meter is pegged - I'm outta here.
I'm the one making wrong assumptions??? Wow! That's rich... considering how many wrong assumptions people have been attributing to my system, on basis that I have no clue about. For example, "security" against criminals is, at best, a side benefit of my system -
not its
raison d'etre - so whether or not it can accomplish that
shouldn't be the main issue here... yet people have somehow decided by some sort of concensus that it is indeed why my system is in place. Talk about wrong assumptions!
Be that as it may, let my try (once again) to explain the laws of physics that I'm referring to. Because people seem to like analogies, here's mine, using a camera as an analogy for a motion sensor:
Let's say a camera is installed, having a 60-degree wide field of view. Under optimum environmental conditions, this camera "sees" whatever exists within that 60-degree field of view, within the constraints of the camera's capabilities. (For instance, a low-res camera might not be able to distinguish objects smaller than, say, 1' tall at distances beyond, say, 30' from the camera... but can distinguish objects larger than, say, 5' tall at distances closer than, say, 80' from the camera). Now, the camera's characteristics or optical factors may prevent it from "seeing" some or all such objects when certain adverse environmental conditions exist - such as rain, snow, fog, darkness, etc. (that might impair the camera's ability to view part or all of it's optimum field of view), or even temperature extremes (that might impair the operation of the camera itself, preventing it from "distinquishing" all objects within of its usual field of view).
The camera's physical
width of field (and therefore the effective boundaries of that field, as imposed on the surrounding terrain) is determined by the physics of the detector and optics of the camera, and therefore will not change (barring any physical deformation of the camera's optics due to extreme temperatures or whatever). Variations of other environmental conditions might affect how far away (
depth of field) the camera can see objects at any given time, but will not affect how
wide the field of view is, because that remains limited by the physical constraints of the optics. Further, the maximum width of view could be narrowed by placing optically-opaque objects near the camera on the sides of its view. Again, environmental conditions may affect how
far the camera can see effectively while these objects restrict the width of view, but the environmental conditions will not alter the width of view.
If we can agree that a camera is a fair analogy of a motion sensor (as was supposed by others earlier in this thread), then let me use this analogy in an attempt to make my point:
Let's say there are two cameras mounted such that their width of views partially overlap at some distance from the cameras, making it possible for both cameras to see the same objects while those objects are in the areas of the terrain where the views of the two cameras overlap. If it is desired to prevent both cameras from viewing the same objects simultaneously, then the camera(s) would need to be adjusted away from each other, or else some blocking object(s) would have to be imposed on the adjacent side(s) of one or both cameras' field of view, so that no overlap of views would exist. Once configured this way, no amount of normal environmental variations would alter the physical limits of the views, to somehow re-impose an overlap condition. Same thing applies to motion sensors: Affects of environmental variations are not going to magically overcome the physical characteristics and expand the width of view so that the sensors' fields of view would again overlap, as some people are claiming.
In order to set up the two cameras so that they view adjacent areas of the terrain without any overlap would require trial and error, by adjusting the cameras and/or any blocking objects and looking at the on-screen image to find out where its boundaries fall in relation to the viewed terrain. Presumably, one would make these observations under reasonably optimal environmental conditions, yet it would be possible to make them under adverse conditions, even in total darkness, by taking some measure to "enhance" the spot being "mapped" - for instance, by placing a small bright light at the spot of interest, or by moving such a light into the field of view from the side until it shows up on the screen. The spot in the terrain where this occurs can then be "mapped" as the edge of the viewed area. Similarly, with motion sensors, it should be possible to "map" the physical sides of the field of view by using some IR "spot source" that is intense enough to overcome any "weak" detection due to adverse environmental conditions, and moving it towards the field of view from the side until it comes into the physical view of the sensor... but the concensus here has been that this is not possible under
any circumstances. I find this hard to believe because it would mean that the motion sensors must "detect" only at random - in which case, they would not be sensors, but just noise sources.
My question all along has been what can be used to provide an intense "spot source" of IR that will definitely trigger a sensor when it moves within the sensor's field, or if there is a better technique that would ensure detections (like maybe how fast or how far to move the "target")... because everything I've tried so far does not seem to have enough "umph" to ensure that the sensor will "see" it move. I fail to understand why any actual or assumed application of my sensors has any bearing on this... at least not beyond establishing the ambient conditions that it would be used in - yet that seems to be the direction this discussion has been pushed into.