Wakali wa Physics manasemaje juu ya hili?

[Mamndenyi]

Mrimi kumbe ndo hilo nalijua ila inavyofanya kazi ndo ntakuwa sijui,
kubwa naona tu wale matraffic huwa wanatabiri tu kama wapiga ramli
wakikuotea tu kimekula kwako.

Hapana,unajua.Usiniambie hujui lile tochi wanalokuwa nalo matrafiki! Labda useme hujui hicho ambacho hata mimi sijui.

 

[KXY]

Kwa ufupi hii torch ina work using the Doppler's effect!

Police Radar
The handheld radar guns used by police to check for speeding vehicles rely on the Doppler effect.

ni LIDAR speed gun au RADAR guns zinazotumika?

Maana teknolojia zake ni tofauti

 

[Gaijin]

ni LIDAR speed gun au RADAR guns zinazotumika?

Maana teknolojia zake ni tofauti

Suala lililoulizwa ninadhani linalenga Lidar na sio Radar guns

Radar guns zinatumia doppler effect wakati Lidar zinatumia reflection tu

 

[Mrimi]

Inapima speed ya gari kwa kupima muda unaochukua mwanga kutoka kwenye "tochi" kufika kwenye gari, kuakisiwa "reflected" na kurudi tena kwenye "tochi"

Kwa kugawa muda huo uliopatikana kwa mbili na kwa vile kasi ya mwanga inajuulikana, basi distance iliyopo gari kutoka "tochi" inaweza kujuulikana.

Kwa vile mwanga unakasi kubwa, ndani ya sekunde unaweza kujua mabadiliko ya distance ya gari kulinganisha na ilipo tochi.

Ukiweza kujua mabadiliko ya distance ya gari with time ndio umeshajua kasi ya gari hiyo

Kwa hiyo in short inachopima ni mabadiliko ya muda utakaohitajika kureflact mwanga kutoka kwenye tochi hadi gari ili kujua mwendo kasi wa gari hiyo

Kwa ufupi hii torch ina work using the Doppler's effect!

Practical Applications of the Doppler Effect

In the 160 years or so since Doppler first described the wave phenomenon that would cement his place in history, several practical applications of the Doppler effect have emerged to serve society. In all of these applications, the same basic thing is happening: A stationary transmitter shoots waves at a moving object. The waves hit the object and bounce back. The transmitter (now a receiver) detects the frequency of the returned waves. Based on the amount of the Doppler shift, the speed of the object can be determined. Let's look at a few specific examples.


Police Radar
The handheld radar guns used by police to check for speeding vehicles rely on the Doppler effect. Here's how they work:

View attachment 77873

1. A police officer takes a position on the side of the road.
2. The officer aims his radar gun at an approaching vehicle. The gun sends out a burst of radio waves at a particular frequency.
3. The radio waves strike the vehicle and bounce back toward the radar gun.
4. The radar gun measures the frequency of the returning waves. Because the car is moving toward the gun, the frequency of the returning waves will be higher than the frequency of the waves initially transmitted by the gun. The faster the car's speed, the higher the frequency of the returning wave.
5. The difference between the emitted frequency and the reflected frequency is used to determine the speed of the vehicle. A computer inside the gun performs the calculation instantly and displays a speed to the officer.

Habari ya Mwaka Mpya wana JF,

Ukweli ni kwamba ile tochi inafanya kazi kwa kupima msukumo wa mawimbi waves compression.

gari linapokua kwenye speed lina sukuma upepo au mawimbi ya upepo kadri gari linapokua na speed kubwa kompression huongezeka so inasoma msukumo ule na kudetermine speed ya gari na wala sio picha au image kama walivyo sema wenzangu na ndio maana hawawezi hata kujua namba ya gari iliyo over speed.

Stay blessed wana JF

Nilikuwa naelekea kuelewa,lakini naona tena kuna dalili za kuyafanya maisha yangu magumu tena katika hii kiku. Now,which is which??!

 

[Kinyungu]

Brother Kinyungu hapo hapo kwenye 105 kwa nini isiwe 100 - 5 = 95km/hr?

Mkuu (+)-(-)=+

 

[Gaijin]

Nilikuwa naelekea kuelewa,lakini naona tena kuna dalili za kuyafanya maisha yangu magumu tena katika hii kiku. Now,which is which??!

Kuna vitu viwili hapa, kuna Radar Guns ambazo ndio zinatumia doppler effect kama ilivyoelezwa na Kalumbesa

Pia kuna Lidar yaani ni ile tochi ya mwanga ambayo inatumia reflection ya mwanga tu kama nilivyoeleza

Kwa hiyo ni vifaa viwili tofauti vinavyotumia nadharia mbili tofauti ila vyote vinatumiwa na polisi kwa kazi moja ya kung'amua mwendokasi wa chombo cha usafiri

 

[Kalumbesa]

Suala lililoulizwa ninadhani linalenga Lidar na sio Radar guns

Radar guns zinatumia doppler effect wakati Lidar zinatumia reflection tu

LIDAR guns are modern, Radar guns have been used way back then! but seems in most countries still radar guns are used

 

[KXY]

Nilikuwa naelekea kuelewa,lakini naona tena kuna dalili za kuyafanya maisha yangu magumu tena katika hii kiku. Now,which is which??!

Kwa kifaa hiki LIDAR speed gun inatumia tofauti ya muda wa laser beam inapotumwa na kurudi baada ya kuakisiwa na kwa sababu speed ya light inajulikana na muda unao unaweza pata speed ya moving object.

Addition: Maelezo ya ziada haya hapa

Inapima speed ya gari kwa kupima muda unaochukua mwanga kutoka kwenye "tochi" kufika kwenye gari, kuakisiwa "reflected" na kurudi tena kwenye "tochi"

Kwa kugawa muda huo uliopatikana kwa mbili na kwa vile kasi ya mwanga inajuulikana, basi distance iliyopo gari kutoka "tochi" inaweza kujuulikana.

Kwa vile mwanga unakasi kubwa, ndani ya sekunde unaweza kujua mabadiliko ya distance ya gari kulinganisha na ilipo tochi.

Ukiweza kujua mabadiliko ya distance ya gari with time ndio umeshajua kasi ya gari hiyo

Kwa hiyo in short inachopima ni mabadiliko ya muda utakaohitajika kureflact mwanga kutoka kwenye tochi hadi gari ili kujua mwendo kasi wa gari hiyo

 

[Mrimi]

Suala lililoulizwa ninadhani linalenga Lidar na sio Radar guns

Radar guns zinatumia doppler effect wakati Lidar zinatumia reflection tu

Mkuu,nadhani hata jamaa anasomeka. Angalia maelezo yake vizuri.Zinaweza teknolojia zikawa tofauti ila zote zikafanya kazi kwa uzuri tu.Sasa swali ni je,hawa jamaa wanatumia ipi sasa,maana inaonekana zote zinafanya kazi hiyo.

 

[Gaijin]

Mkuu,nadhani hata jamaa anasomeka. Angalia maelezo yake vizuri.Zinaweza teknolojia zikawa tofauti ila zote zikafanya kazi kwa uzuri tu.Sasa swali ni je,hawa jamaa wanatumia ipi sasa,maana inaonekana zote zinafanya kazi hiyo.

Hakuna sehemu hata moja niliyosema moja haifanyi kazi vizuri.

Nilichosema ni kuwa nadharia mbili tofauti kwa vifaa viwili tofauti ambavyo vinatumiwa na polisi kung'amua mwendokasi wa chombo cha usafiri hususan gari

kama ni tochi ya mwanga basi ni LIDAR kama ni tochi ya rada basi ni RADAR Gun, wanachokitumia "jamaa" mimi sikijui kwa kweli kwa sababu hapo utakuwa unanitoa kwenye physics unaniingiza kwenye "sayansi ya utabiri"

 

[Kalumbesa]

Hakuna sehemu hata moja niliyosema moja haifanyi kazi vizuri.

Nilichosema ni kuwa nadharia mbili tofauti kwa vifaa viwili tofauti ambavyo vinatumiwa na polisi kung'amua mwendokasi wa chombo cha usafiri hususan gari

kama ni tochi ya mwanga basi ni LIDAR kama ni tochi ya rada basi ni RADAR Gun, wanachokitumia "jamaa" mimi sikijui kwa kweli

Gaijin zote ziko in use ila LIDAR ni newest technology inaonekana nchi nyingi hazija migrate full kutumia hizi,most Low developing countries RADAR guns zinatumika zaidi. Kila moja zina challenge zake na advantage zake na LIDAR are definitely used more in Developing countries and they are more expensive. More..............

In 1989, the introduction of lidar as an alternative to radar for speed enforcement hit many traffic divisions with an avalanche of hype, excitement and confusion. Unfortunately, many of the first-generation lidar units were heavy, bulky and expensive, and before officers and the courts could accept lidar units, questions about their accuracy and reliability needed to be answered. Today, technological advances have removed many of those earlier obstacles. Numerous traffic officers around the country now utilize lidar, and the courts have also seen the light.
How does radar stack up to this new kid on the block? Is radar ready for retirement? Although radar units have been around for years and seem unchanged, they aren't exactly stuck in the dark ages. Technological advances have produced new features, some of which remain unseen by the user, such as the conversion from analog to digital signals. Other improvements-same direction, fastest mode, etc.-have changed the way many officers perform their enforcement duties.
So, before you submit a purchase order for the latest and greatest lidar unit and haul all of your radar guns to the curb for your department's annual garage sale, consider the capabilities of both technologies and figure out exactly what your department needs.
Basic Principles
Radar (radio detection and ranging) units transmit radio waves at a designated frequency that reflect off of a moving target vehicle and return to the unit. The difference between the transmitted frequency and the return frequency is called the Doppler frequency or Doppler shift, which is used to determine the target vehicle's speed. The greater the shift received by the unit, the greater the speed. Counting units convert the frequency shift into a speed reading displayed by the radar unit in miles per hour.
Aiming the radar in the general direction of the target vehicle allows the operator to get a nearly instantaneous reading. The radio waves shoot out in a cone-shaped pattern that covers roughly two-thirds of a football field at a range of 1,000 feet. The radar unit will display the strongest return signal it receives, and a Doppler tone helps the officer confirm the reading is coming from the intended target.
Lidar (light detection and ranging), on the other hand, sends out a laser beam. The initial bursts of light allow the lidar unit to determine the distance to the target vehicle by calculating the time it takes the beam to reflect off of the vehicle and return to the unit. As the vehicle gets closer to (or farther from) the unit, this distance changes. Lidar units use this change in distance and time as key components to determine the target vehicle's speed. Mathematical formulas help ensure the calculations are accurate and that the lidar unit displays only valid speed readings.

The laser beam is very narrow (about 4 feet wide at 1,000 feet), which allows the lidar operator to select the target vehicle. The lidar signal only hits one vehicle, so there's little doubt which vehicle's speed the unit displays. As an operator, you can obtain a speed reading for a specific vehicle as long as you have a direct line of sight with that vehicle.
Working with Radar
The fastest-mode capability of radar allows you to receive a speed reading from a target vehicle even when the vehicle does not produce the strongest signal. Generally, a smaller vehicle, such as a motorcycle, may not produce a speed reading if a larger, closer vehicle (SUV) returns a stronger signal to the device. When in fastest mode, however, a radar unit not only displays the vehicle returning the strongest signal, but also the vehicle traveling the fastest. (In the event the fastest vehicle also returns the strongest signal, the unit displays only that vehicle's speed.)
When using lidar, officers must maintain a direct line of sight and keep the lidar signal on the same area of the vehicle until they obtain a speed reading. While not extremely difficult, it does take slightly longer than receiving a reading using radar. (To obtain readings more easily, use a shoulder stock or tripod to steady the device.) Keeping the lidar signal on the target vehicle should not be a major obstacle, but given situations such as the motorcycle and SUV noted above, many officers prefer to use radar in fastest mode to easily obtain the speed of the motorcycle.
In terms of enforcement, the ability of radar to operate in the moving mode is the most significant difference between the two technologies. Currently, lidar cannot operate while moving. No way around this one. If you want to perform speed enforcement while driving around, radar is currently the only game in town other than the traditional (and generally less effective) pacing option. A moving-mode radar unit with two antennas and same-direction capabilities can get speed readings from target vehicles whether the vehicle is approaching or receding from your vehicle, and whether the target vehicle moves in the same or opposite direction as you. Additionally, some locations prove extremely difficult or impractical to use stationary radar or lidar for enforcement. Therefore, moving-mode enforcement is an extremely effective and useful capability.
Working with Lidar

When trying to get a speed reading of the motorcycle going 80 mph passing the SUV going 65 mph, a lidar operator simply aims at the motorcycle. Lidar units don't have or need fastest mode because lidar targets only the vehicle the officer chooses. Many vehicles can simultaneously travel through the wide radar beam, which can bring into question which vehicle produced the displayed reading. (A defendant may bring up this argument in court, but an experienced, well-trained officer should be able to testify as to their tracking history, i.e., how they knew the defendant's vehicle was producing the displayed speed reading and, subsequently, that the ticket is valid.)
Radar units use a Doppler tone to help the officer confirm the speed displayed by the unit is actually the intended target vehicle's speed. Lidar units do not provide a Doppler tone because they display the speed of only the vehicle the officer selects. Lidar does have a target-acquisition tone that remains constant regardless of the speed of the target vehicle (one particular unit simulates a Doppler tone that does correspond to the speed of the vehicle). The tone confirms that the officer has, in fact, obtained a valid speed reading.
Lidar has some unique capabilities as well. For example, when coupled with a mapping program, the range mode on a lidar device provides quick, easy and professional documentation of traffic collisions and crime scenes. If your department does not have the budget for expensive (and bulky) surveying equipment, a lidar with mapping capabilities may be just the ticket. Lidar can instantly give an officer an accurate measurement of objects several thousand feet away. At the scene of a collision, a traffic officer can quickly (and safely) measure an intersection without leaving the curb. In the case of a crime scene, indoors or out, a lidar's mapping software can produce detailed diagrams without touching or moving evidence.
Making the Buy
There's a lot of information out there about both radar and lidar, and many experienced officers have strong opinions on which device is better. I can sum up all the arguments on which unit to buy quite simply: It depends. First, take a look at the type of enforcement you do and the environment in which you work. Although most locations provide prime conditions for either radar or lidar enforcement, at some locations, or even at different times at the same location, you'll find it beneficial to use radar instead of lidar or vice-versa. Do you need moving-mode capability, or will a stationary lidar suffice?

Second, seek input from surrounding agencies that work speed enforcement on similar roadways. Look at the equipment they use and ask about their experiences both in the field and in court.
Many manufactures will provide radar and lidar units to your department for evaluation. Take advantage and try their products
Train & Maintain
Over the many years of radar-based speed enforcement, several key court decisions have shown that a properly working radar unit in the hands of a well-trained officer can accurately measure vehicle speed.
Many of these court cases have since been cited in lidar cases, resulting in similar decisions on the reliability of a lidar unit's ability to accurately measure speed. I cannot stress enough that these court decisions were based on the operator's training and the maintenance of the equipment. Maintain your skills through continued training and yearly recertification, and keep a log of all formal and informal training you do. And stay up-to-speed on the latest and greatest products in real-world enforcement settings. This will enable you and your department to make intelligent decisions about the type of unit, the manufacturer, makes, models and even the various features you need or prefer.
If you purchase the best unit money can buy, it may turn out to be a costly mistake if the equipment doesn't fit your needs.

 

[Mrimi]

Sina hakika ni wangapi tutakuwa tumenufaika na somo hili,ila niseme tu kwamba kwa upande wangu nimenufaika kuliko hata nilivyotarajia.

Asante sana:

Gaijin
Kalumbesa
KXY

Long live Jamii Forums.

 

[Kifarutz]

Mkuu (+)-(-)=+

Hewallah, sasa funguka unidadafulie hiyo -(-) inatokea wapi kwani kama speed ya torch ya trafic ni +5 na incoming vehicle lipo +100 but since the torch reads the vehicle in opposite direction inatakiwa iwe -100 ambako plus +5 inakupa +95!

 

[JosephElly]

Dopler Effect... Kwa concept ya dopler.. hapo ile tochi inatoa ligth rays katika frequency fulani.. na hupima muda uliotumika mpaka rays zile kurudi tena katika source ambayo ni ile tochi... Kwa hii concept ni lazima hii process ifanyike mara 2 au zaidi ili kupata accurate speed ya moving object (Gari).

 

[Kinyungu]

Hewallah, sasa funguka unidadafulie hiyo -(-) inatokea wapi kwani kama speed ya torch ya trafic ni +5 na incoming vehicle lipo +100 but since the torch reads the vehicle in opposite direction inatakiwa iwe -100 ambako plus +5 inakupa +95!

Unajua basics formula ya kutafuta relative speed/velocity?

 

[Kifarutz]

Unajua basics formula ya kutafuta relative speed/velocity?

Kinyungu hayo mambo nimesoma 1996, 17yrs ago na since then I have looked on them again..! Wewe tiririka tu..!

 

[Gaijin]

Hewallah, sasa funguka unidadafulie hiyo -(-) inatokea wapi kwani kama speed ya torch ya trafic ni +5 na incoming vehicle lipo +100 but since the torch reads the vehicle in opposite direction inatakiwa iwe -100 ambako plus +5 inakupa +95!

Kama speed ya vehicle ni negative (-100) basi speed tochi ni positive (+5) kwa sababu inakwenda kwenye upande unaokinzana na gari.

Ukitaka kutafuta relative velocity, maana yake ni kuwa unatafuta tofauti ya velocity baina ya hivyo vitu viwili vinavyotembea hivyo utalazimika kuchukua speed moja unatoa speed nyengine kwa hiyo itakuwa -100 - (+5)= -105 ambayo unapunzungumzia relative velocity alama ya + au - inaonyesha tu direction

 

[Kinyungu]

Kinyungu hayo mambo nimesoma 1996, 17yrs ago na since then I have looked on them again..! Wewe tiririka tu..!

Gaijin amesaidia kufafanua hapo chini..hebu soma labda utaelewa

 

[TAMKO]

All Lidar are Radar but not all Radar are Lidar as far properties detection devises is concern.

Maembe yote ni Matunda lakini Matunda yote SIO maembe

Matatizo makubwa ya Radar systems hata cctv, dome cam zote ni radar groups ni positioning. Ukiongelea position ya speed detecting systems ambazo zipo za aina tele, kila moja ina uchawi wake unapoinstal hasa positioning, ili ifanye Kazi Kwa ubora inaoridhisha lakini si 100%. Ukiongelea sana makitu haya utaona funny comment alopost one member humu Kwamba traffick wanabashiria tu na ukilegea unachangia matofali mawili matatu au bia kadhaa Basi safari inaendelea ni kweli lakini bora kuwa Na kitu kuliko kutokuwa nacho kabisa.

Tatizo mjadala uwe Lengo la Matrafik hawa, kimsingi lengo Lao si kumkumbisha Dereva Na wajibu Wake wa kuheshimu alama Za pito bali ni kumnasa Na kumkomoa kimtoke 'kitu'. Hapana utu kabisa, Matrafik njiani ni maadui kwa wenye vyombo vya usafiri. Mtu ukiwa Na GARI yako njiani hasa Kama una safari ya mikoani ukiiona serikali (trafick) njiani , Unapaswa ufurahi, usimamishe gari usalimiane nao ujione kwamba uko salama mikononi mwa serikali lakini sivyo kwetu, ukishaona Hata raia tu kavaa kanyelamumo jeupe up-down moyo unalipuka unadhani trafick unajikumbushia madhambi yoote ya GARI lako Kama yapo.

Sidhani kama ni Utamaduni mzuri Kwa jeshi hili , lakini kinginea neno traffick manaake msongamo, hawa watu wameacha Kazi zao Za kupangua msongano Na kuingilia Kazi Za ma Vehicle inspector, motion control dept , driver behavior cops Na nyinginezo. Ukiwauliza wewe unanikamata kama nani atakujibu tunawasaidia wenzetu hawatoshi, Nchi hii Hata wewe ukavaa mguo mweupe ukasimama kona Za msata hivi jioni lazima uhesabu laki Sita Saba ivi

 

[Petro E. Mselewa]

Itakuwa ni Law of motion Mkuu...LOL!