Hi All,angle. We want to keep the sensor stationary.
I am working on a project: we have a light sensor with only around 40 degrees field of view. Our goal is to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different
I was thinking about using a set of lenses to change the angle of the rays but I am stuck, since one lens would only focus the parallel rays of different angles to different points in the focal plane - and our sensor has a fairly small surface area.
Some of the diffusers I have found were only changing the angles with up to 10 degrees which is not enough, since we want to measure from -75 to 75 degrees.
Another concern is to find a solution which doesn't filter out much of the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
Hi All,angle. We want to keep the sensor stationary.
I am working on a project: we have a light sensor with only around 40 degrees field of view. Our goal is to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different
I was thinking about using a set of lenses to change the angle of the rays but I am stuck, since one lens would only focus the parallel rays of different angles to different points in the focal plane - and our sensor has a fairly small surface area.
Some of the diffusers I have found were only changing the angles with up to 10 degrees which is not enough, since we want to measure from -75 to 75 degrees.
Another concern is to find a solution which doesn't filter out much of the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
On 2017-10-04 03:55, malna.polya@gmail.com wrote:
Hi All,
I am working on a project: we have a light sensor with only around 40
degrees field of view. Our goal is to measure the strength of the
sunlight without introducing too much of a bias based on the time of
the day - when the sun shines at a different angle. We want to keep
the sensor stationary.
I was thinking about using a set of lenses to change the angle of the
rays but I am stuck, since one lens would only focus the parallel rays
of different angles to different points in the focal plane - and our
sensor has a fairly small surface area.
Some of the diffusers I have found were only changing the angles with
up to 10 degrees which is not enough, since we want to measure from
-75 to 75 degrees.
Another concern is to find a solution which doesn't filter out much of
the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
Other posters have more experience and might comment on this, but I have
got a feeling that the theorem of conservation of etendue makes what you
want impossible. If you want to decrease the angular spread of a source
(and this is what you want to do: a source emitting at different angles
for different times is the same as a source emitting at different angles
at the same time for what regards the theorem) then you have to increase
the area which the light crosses. I think this is what is happening in
the solution with a set of lenses.
On 10/04/2017 04:29 AM, JTS wrote:
On 2017-10-04 03:55, malna.polya@gmail.com wrote:
Hi All,
I am working on a project: we have a light sensor with only around 40
degrees field of view. Our goal is to measure the strength of the
sunlight without introducing too much of a bias based on the time of
the day - when the sun shines at a different angle. We want to keep
the sensor stationary.
Another concern is to find a solution which doesn't filter out much of
the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
Other posters have more experience and might comment on this, but I have
got a feeling that the theorem of conservation of etendue makes what you
want impossible. If you want to decrease the angular spread of a source
(and this is what you want to do: a source emitting at different angles
for different times is the same as a source emitting at different angles
at the same time for what regards the theorem) then you have to increase
the area which the light crosses. I think this is what is happening in
the solution with a set of lenses.
The OP can do pretty well with a non-imaging concentrator run backwards,
i.e. small end towards the sky. Of course it has to be smallish in
order for the big end to fit the available detector, and there's still a cosine rolloff due to obliquity.
On Tuesday, October 3, 2017 at 9:55:37 PM UTC-4, malna...@gmail.com wrote:angle. We want to keep the sensor stationary.
Hi All,
I am working on a project: we have a light sensor with only around 40 degrees field of view. Our goal is to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different
I was thinking about using a set of lenses to change the angle of the rays but I am stuck, since one lens would only focus the parallel rays of different angles to different points in the focal plane - and our sensor has a fairly small surface area.
Some of the diffusers I have found were only changing the angles with up to 10 degrees which is not enough, since we want to measure from -75 to 75 degrees.
Another concern is to find a solution which doesn't filter out much of the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
Forest Mims has a whole bunch of stuff using led's to measure sky light. http://www.forrestmims.org/scientificresearch.html
(I don't know if that's what you're trying to do.)
How about a number of sensor's pointing in different directions,
then keep track of the time of day. And do some math.
Why don't you want to use a solar tracker?
George H.
Hi All,angle. We want to keep the sensor stationary.
I am working on a project: we have a light sensor with only around 40 degrees field of view. Our goal is to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different
I was thinking about using a set of lenses to change the angle of the rays but I am stuck, since one lens would only focus the parallel rays of different angles to different points in the focal plane - and our sensor has a fairly small surface area.
Some of the diffusers I have found were only changing the angles with up to 10 degrees which is not enough, since we want to measure from -75 to 75 degrees.
Another concern is to find a solution which doesn't filter out much of the light spectrum.
Does anyone have any ideas on how to solve this challenge?
Thank you in advance!
I am working...to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different angle. We want to keep the sensor stationary.
On Tuesday, October 3, 2017 at 6:55:37 PM UTC-7, malna...@gmail.com wrote:
I am working...to measure the strength of the sunlight without introducing too much of a bias based on the time of the day - when the sun shines at a different angle. We want to keep the sensor stationary.
Well, the classical approach is to use a crystal ball, and a carved wooden screen.
Really: <http://www.kuriositas.com/2011/02/campbellstokes-sunshine-recorder.html>
On Tuesday, October 3, 2017 at 6:55:37 PM UTC-7, malna...@gmail.comrecorder.html>
wrote:
I am working...to measure the strength of the sunlight withoutWell, the classical approach is to use a crystal ball, and a carved
introducing too much of a bias based on the time of the day - when the
sun shines at a different angle. We want to keep the sensor stationary.
wooden screen.
Really:
<http://www.kuriositas.com/2011/02/campbellstokes-sunshine-
On Mon, 09 Oct 2017 16:38:18 -0700, whit3rd wrote:
On Tuesday, October 3, 2017 at 6:55:37 PM UTC-7, malna...@gmail.com
wrote:
I am working...to measure the strength of the sunlight without
introducing too much of a bias based on the time of the day - when the
sun shines at a different angle
Well, the classical approach is to use a crystal ball, and a carved
wooden screen.
Interesting approach, but for simple electronic monitoring with no moving parts how about the method used by photographic lightmeters for omnidirectional measurement, a spherical diffuser placed over the
detector,
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