Questions tagged [sensor]

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Help with estimating odometry using two lidar sensors with known extrinsic calibration

I have a setup consisting of two lidar sensors with a known extrinsic calibration. Both lidars have messages with the same timestamps (no timedelay between them). My goal is to estimate odometry using ...
aguero's user avatar
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1 answer
32 views

Is photon emission density is same or random everytime?

I want to know if photon density changes over time. By density, I mean number of photon hitting a surface in time. I am not asking about the direction of emission which is random. What I mean is that ...
Unknown's user avatar
1 vote
1 answer
51 views

Calibrating an inertial measurement unit (IMU) to zero/flat surface

I am building a digital spirit level using an inertial measurement unit (IMU), and I want to calibrate the device so that it shows the angle correctly. Does anybody here have experience with this kind ...
eidetech's user avatar
1 vote
0 answers
40 views

Question regarding converting analog sensor value into mA [closed]

I'm doing a project with an absolute humidity sensor. When I bought an absolute humidity sensor and implemented it into a machine, I expected the output value to be representative of absolute humidity,...
Paul Pham's user avatar
2 votes
2 answers
32 views

Remote mass detection and location

Could a collection of gravitational sensors (eg. MEMS accelerometers), placed in a 3d grid (eg. 10 x 10 x 10 sensors forming a 1 x 1 x 1 m cube) detect the the presence and position of a remote mass ...
dronus's user avatar
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4 votes
2 answers
63 views

What's the best way to measure a magnetic field?

I work in a physics lab. ...
yfs's user avatar
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0 answers
24 views

Can the receiver of an IR sensor pick up the signal from another IR sensor?

So I was trying to find a way to transmit a particular signal. I was thinking of getting one IR sensor to transmit a signal, which would be picked up by the receiver of another IR sensor. However, as ...
anon's user avatar
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0 answers
89 views

Path reconstruction from accelerometer and gyroscope data

I found a dataset here whose columns are attitude.roll, attitude.pitch, attitude.yaw gravity.x, gravity.y, gravity.z rotationRate.x, rotationRate.y, rotationRate.z acceleration.x, acceleration.y, ...
Alberto Carraro's user avatar
1 vote
1 answer
65 views

How can I determine how much energy a sensor pixel can withstand before exploding? [closed]

I am trying to design a camera system to image a laser beam. I know the sensor is a Sony IMX226, and I have the data sheet for this sensor. The data sheet, however, does not list a maximum energy ...
Benzene enthusiast's user avatar
0 votes
1 answer
38 views

Which neutral atom-based quantum sensor is hardest to build/operate?

I am currently going through the presentation, "Sensing with neutral atoms", by Grant Biedermann. I understand that, according to the talk, there are a large number of different sensing ...
Omar Shehab's user avatar
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0 answers
42 views

In a light plasma, how many electrons pass through a given area

Assume you have a light plasma of about 10^5 particles per cm^3. The energy-density of the plasma is about 0.1eV (as in near earth orbits, see here: http://assets.press.princeton.edu/chapters/s9500....
jjstcool's user avatar
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1 answer
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When should smartphone be declared as static using accelerometer reading? [closed]

I wish to know when should I declare an smart phone static by reading its 3 axis accelerometer reading. I have notice that modulo of all 3 axes gives 9.8 when ever smart phone is static. What does it ...
tomtom's user avatar
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13 votes
1 answer
1k views

How can one detect a device (phone) falling using its 3-axis accelerometer?

I am working on an Android app to use its 3-axis inbuilt accelerometer to find if the phone falls. I googled and found that if the following value is less than 2: $$a = \sqrt{x^2 + y^2 + z^2}$$ (where ...
tomtom's user avatar
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1 answer
177 views

What does photon-limited imaging mean?

The following link is about Photon-Limited Imaging, https://engineering.purdue.edu/ChanGroup/project_QIS.html. Is there any definition of Photon-Limited Imaging. From the paper Photon-Limited Object ...
Jogging Song's user avatar
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0 answers
29 views

Is it possible to obtain noise level in electrons using only one camera?

In the link, https://www.photonstophotos.net/GeneralTopics/Sensors_&_Raw/Sensor_Analysis_Primer/Photon_Transfer_Curve.htm there is one figured called Standard Photon Transfer Curve – Multiple ISOs ...
Jogging Song's user avatar
1 vote
1 answer
73 views

How does a sampling rate of 1ns equate to 15cm for an optical instrument?

I’m currently working with open source data captured by the NASA GEDI LiDAR instrument and I am applying a math model to it. GEDI’s sampling rate is said to be 1 nanosecond or 15 centimeter resolution....
Brandon's user avatar
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2 votes
2 answers
154 views

Is Daredevil's superpower conceptually possible?

The Marvel superhero Daredevil is blind but has heightened senses, enabling him to perceive the world around him to a far greater extent than a regular person. In his depiction in the Netflix live-...
dbmag9's user avatar
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1 answer
40 views

Principle of operation of a Gyroscope-Free IMU

What is the principle of operation of a Gyroscope-Free IMU, or how can angular accelerations and velocities be measured with accelerometers?
lkdo's user avatar
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1 vote
2 answers
674 views

What is the negative pressure?

I have vacuum pump connected to quartz tube and vacuum sensor, when the pump reaches it max value the sensor reading (-1 bar) and the analog gauge in the pump reach the max value which is (-1000mbar). ...
Mohamed Refaey's user avatar
0 votes
1 answer
94 views

What is the intuition behind excluding the effect of gravity from accelerometer data

In the unit of accelerometer and linear acceleration, I see that accelerometer is angular and the linear acceleration is linear. There is the impact of gravity on the accelerometer. However, ...
Mas A's user avatar
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4 votes
1 answer
355 views

Is there any sensor that creates a visual image of magnetic fields?

I am working on a project where I am trying to create a magnetic tag that can be detected from $20 - 50$ cm away. Is there any sensor on the market capable of this?
Bubu's user avatar
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1 vote
3 answers
217 views

The change of mechanical into electromagnetic waves and vice versa [closed]

I know that sound is a type of mechanical wave, so the human eardrum changes mechanical energy into electronic energy (impulses) so the information may be processed by the brain. Question: As ...
12eStark's user avatar
0 votes
1 answer
86 views

Compute capacitance of planar interdigital electrodes

My apologies if this is not the right place to post a question like this. I am looking to do post-grad research study next year in the sensory field for sensing gases like hydrogen, nitrogen or ...
David Norman's user avatar
0 votes
0 answers
28 views

PVDF sensor response time

I am trying to measure the voltage response from a high energy impact using the PVDF sensors. Here is a description of the experiment. I would like to measure the high impact energy on the aluminised ...
lqope54's user avatar
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0 votes
1 answer
87 views

Through-metal-wall Ultrasound sensor imaging?

A while ago, MIT published a paper that used a radar sensor to take a low-res image, and then they trained an AI model to convert the image into a human skeleton for through-wall human pose detection. ...
Shrey Joshi's user avatar
1 vote
1 answer
130 views

Does the size of CCD/CMOS of a telescope affects the magnification?

For a normal, traditional telescope, the magnification level should equal to focal length divided by eyepiece diameter, i.e., $$Res=\frac{f}{D}$$ So does the size of the CCD/CMOS the same as eyepiece ...
Jack the Ranger's user avatar
3 votes
1 answer
60 views

Why do the sensitivities of magnetometers and gravimiters have such strange units?

It looks like the sensitivities of magnetometers and gravimeters are usually reported with the units of $\text{Tesla}/\sqrt{\text{Hz}}$ and $\text{Gal}/\sqrt{\text{Hz}}$, respectively (where "Gal&...
Very Tiny Brain's user avatar
0 votes
1 answer
55 views

Does a tuning fork's resonance frequency increase with a repulsive force on it in AFM?

I have a tuning fork sensor with a probe tip that would be used in atomic force microscopy. Am I correct that the quartz tuning fork's resonance frequency increases with a repulsive force on it and ...
ExactPlace441's user avatar
0 votes
0 answers
33 views

Clarifications on the calibration of a magnetometer?

I've been reading up on magnetometer calibration (sensor fusion in general) recently and got confused about some things. To my understanding, hard iron effects (e.g. inductors and magnets) which are ...
Tuur Bruneel's user avatar
2 votes
1 answer
294 views

How is measurement uncertainty defined / calculated (of a sensor or measurement)?

Textbooks and online sources often say the industry standard for uncertainty is given at a confidence interval of 95 %. This means out of 100 measurements, 95 would achieve the specified value and ...
BetweenBeltSizes95's user avatar
0 votes
2 answers
57 views

Is there any way to differentiate UV light from visible or IR light?

I'm working on a small sensor system that responds to only UV light and I wanted to know that is there any way to differentiate between UV light and the rest of the spectrum like using lens if so then ...
GURU PRASAD A S's user avatar
1 vote
0 answers
28 views

Brightness Temperature layered atmosphere

I'm trying to figure out how to apply the radiative transfer model to calculate the brightness temperature Tb in microwave (Rayleigh–Jeans approximation) considering atmosphere and no scattering. If I ...
Rick's user avatar
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0 votes
1 answer
757 views

How exactly does a (capacitive) humidity sensor work?

How exactly does a humidity sensor work? For example, how can it differentiate between a relative humidity of 30 % and 35 %? I know how a capacitance works but for me that principle is way too high ...
Ben's user avatar
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0 votes
1 answer
27 views

What is a piezoelectric sorption detector?

I'd like to know what a piezoelectric sorption detector is. I can hardly find information about, only a small number of research papers which are mostly not accessable for me. Only given from the term ...
Ben's user avatar
  • 1,467
0 votes
2 answers
106 views

Measuring real time water usage with live water pressure monitoring

My home started seeing high water bills recently. My water company doesn't provide live water meter readings. There is a water meter on the street which I can monitor while water is being used but I ...
user3761169's user avatar
0 votes
1 answer
89 views

How does a weather station temperature sensor work? (physics behind)

In an automatic weather station, a temperature-measuring electronic sensor (which is typically 1,5 m in the air above a grassy ground and covered from direct sunlight) is in a certain way coupled to ...
DanielC's user avatar
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0 votes
0 answers
49 views

Any method to detect extremely weak electromagnetic wave signal? (10^12Hz, level ~10^(-28) Watt per meter^2 per Hz)

Could you please let me know whether there is any method on the Earth to detect some EXTREMELY weak electromagnetic wave signal, if it is a planar wave, if its exact waveform is completely known (...
Wein's user avatar
  • 31
1 vote
1 answer
35 views

Measure fluid speed by using a hot plate [closed]

I would like to figure out whether it is possible to measure the speed of a fluid by letting it flow across a hot plate. I was thinking about using the formulas for forced convection. The plate is ...
Lauran's user avatar
  • 11
1 vote
0 answers
127 views

Accelerometer vs linear acceleration during an impact

I am trying to understand the relation between the accelerometer and linear acceleration during impacts. At work we have an accelerometer and gps onboard sensors installed in a few cars. The ...
halien69's user avatar
1 vote
0 answers
980 views

Graph analysis of accelerometer data

I used my mobile accelerometer sensor to collect data from a moving bike where I held it in my hand in a way that the smartphone sensor +Y axis is in the direction of the moving bike always. This can ...
MKC's user avatar
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2 votes
0 answers
84 views

What does it mean by (±20%) in sensitivity of a pressure sensor?

Sensitivity: (±20%) 15.5 pC/psi (225 pC/bar) this the sensitivity rating of a pressure sensor. what does it mean by (±20%).
Hemanth kumar's user avatar
0 votes
0 answers
26 views

How to measure distance between object and mobile phone using camera? [duplicate]

I am trying to determine the distance between object being photographed and the mobile camera which is capturing the photo. The only device that is used is mobile phone, can we get depth or distance ...
TShashank's user avatar
0 votes
1 answer
55 views

Total output power of a laser

What is the interpretation of and the difference between the total power and total output power of a pulsed laser? How are these parameters measured and which type of detectors are the most ...
Tiswell's user avatar
0 votes
1 answer
207 views

Slots in optical incremental encoder

How can I calculate the amount of slots I need in my optical incremental encoder 's code wheel? For example, how many slots there should be, if I want to determine the position of screw which is ...
Shaun's user avatar
  • 3
2 votes
1 answer
76 views

How LHC sensors work? [closed]

newbie here. I am here because after working with Raspberry Pi sensors and Analog to Digital converters, and computer processors, I wondered how exactly do sensors in large scale physics experiments ...
Tuomas Talvitie's user avatar
-1 votes
2 answers
181 views

Would a speed camera register more speed if it moves in the opposite direction than the object it's measuring?

Earlier today, I was talking with my friend about speed cameras measuring different speeds when moving. This is the situation: I am the red car and I'm driving ...
verfluecht's user avatar
0 votes
1 answer
187 views

Basics of camera calibration

I tried to find some useful explanation about camera calibration and stereo camera setup in the web but was completely overwhelmed by the hairiness of the content: but seriously though, does it have ...
unfinished_sentenc's user avatar
0 votes
1 answer
50 views

Why photodiode measures random phase superpositions on continuous-wave (10kHz) white light?

I measured a 10 kHz modulated white light using a photodiode (Thorlabs PDA10A): Unexpectedly, the photodiode output sensitively depends on the orientation and position of the photodiode. For two ...
WDC's user avatar
  • 257
0 votes
1 answer
49 views

Unique optical map of a uniform metal object

Given a metal object (let us say a perfect planner uniform surface) that has been exposed to external environment factors such as sun, wind, rain and others for couple of years. This object has been ...
Humam Helfawi's user avatar
0 votes
2 answers
766 views

Measuring pressure or weight from an uneven weight distributed surface

I am new here so I hope I'm posting it at the correct place. I am having some troubles with some of my force sensors. My case is like this: I have a body which have a weight. However, the surface is ...
Stanley Setiawan's user avatar