Electronic systems for distance ranging (measuring distance) include Sound Navigation And Ranging (SONAR), Radio Direction And Ranging (RADAR), and LIght Detection And Ranging (LIDAR). These systems all use the same general principles to determine the distance to an object (the target). They all consist of an energy source and a method of detecting the reflected signal and examining it to determine various things about that object. One of the most common of these applications is determining
the distance, or range, to a target.

RADAR is commonly used to detect and monitor relatively large objects, such as aircraft and automobiles. SONAR is commonly used to detect and monitor underwater objects, such as submarine craft and fish. LIDAR, a Magic Mesh relatively new technology, has a number of uses, such as distance measurement for surveying and construction, military range finding, vehicle detection at toll booths and the distance between vehicles.

One of the newest applications of LIDAR is Adaptive Speed Control for automobiles. In this application the cruise control is set by the driver to the max burn speed he or she wishes to travel, just as in other cruise control systems.

However, as the vehicle approaches a slower moving vehicle, the adaptive speed control reduces the vehicle’s speed to match that of the vehicle ahead while maintaining a safe distance. Th is article discusses the principles and design of the front end of an automotive adaptive speed control circuit.

System Alternatives

The possible methods used by such a system include the use of Continuous Wave (CW) signals or pulsed signals.

CW systems HGH operate on the principle that the target reflects a phase shifted version of the transmitted signal. A phase comparator in the receiver compares the phase shifted version of the received signal with the original signal. The phase difference between the transmitted and received signals and the rate of change of this difference can be used to determine distance and rate of change of distance, or rate of closure.

In a pulsed laser system, short light pulses are sent and received. Th e Time Of Flight (TOF) and its rate of change are used to determine the range of (distance to) the target and the rate of closure. These systems all require the use of an electrical signal source, a power amplifi er and a transmitter to send out a signal and a receiving sensor, amplifier, signal conditioner, and a high-speed Analog-to-Digital Converter (ADC) to deliver a digitized version of the received signal to memory, from which a DSP, FPGA, or microcontroller recovers the data at a lower-rate for processing.

A major disadvantage of CW systems in automotive applications is the system cost. A LIDAR system using a pulsed laser provides a much more cost-eff ective solution, so it tends to be the architecture of choice.

System Requirements

The distance that can be measured depends upon several factors, including the peak power of the transmitted signal, argan oil the signal divergence and dispersion, the transmittance of the medium through which the signal travels, target refl ectivity, and the receiver sensitivity.

The range or maximum measurable distance to a target depends upon the laser output power, the optical sensitivity of the receiver, how well the atmosphere transmits optical energy, and how much the laser beam diverges from a perfectly straight path.

There are three basic detector choices for picking up low light levels in the receiver: the silicon PIN detector, the silicon avalanche photo diode (APD), and the photomultiplier tube. APDs are widely used in many applications because they off er a combination of high right to bare legs speed and high sensitivity that is unmatched by other detectors.

The receiver APD converts the received light pulses to electrical currents proportional to the amount of light that falls upon it. A trans impedance amplifier is then used to convert this current to a voltage.

Lady Gaga kicked off her hotly awaited Born This Way Ball at Seoul, South Korea’s Olympic Stadium on Friday (April 27) in front of 45,000 fans, and despite protests from Christian groups saying Mother Monster was “obscene” and could “taint” young people with her performance, the concert appears to have gone on without incident.

Intrepid Twitter fans are already showing off pictures and video of the BTW Ball’s enormous Gothic castle backdrop and myriad costume changes, making it clear that Gaga has outdone even her own Monster Ball in terms of spectacle.

While we wait for reviews to trickle in from halfway around the world, one thing is certain: No minors were corrupted at the show. Earlier this month, the Korea Media Rating Board decided to elevate the age rating for the concert from 12 to 18, prohibiting minors from seeing the concert. When the board notified Gaga’s tour promotion company and a sponsor of the change in age restrictions, it did not offer a reason why the show ? which at the time was still in rehearsals and had not been reviewed publicly ? was considered unsuitable for children under 18.

The likely catalyst for the board’s decision came more into focus as the concert neared and protests from a group of conservative Christians calling itself the Alliance for Sound Culture in Sexuality ramped up. The group covered Seoul with posters accusing Gaga of “spreading unhealthy sexual culture” through “lewd lyrics and performances.”

The superstar and her fans, however, were undeterred. Though she tweeted her hopes that the Korea Media Rating Board would reverse its decision (it didn’t), she continued on as planned. Many fans reportedly arrived at the show wearing versions of Gaga’s most well-known flamboyant costumes, and there have been no reports of disturbances at the concert.

Before the show, Gaga tweeted, “I can you hear you Korea. I’m shaking.”

Gaga’s performance was heavy on material from her Born this Way album, though her biggest hits, including “Bad Romance,” Poker Face” and “Just Dance,” were represented.

Lady Gaga’s Born This Way Ball set list:

» “Highway Unicorn”
» “Government Hooker”
» “Born This Way”
» “Bloody Mary”
» “Bad Romance”
» “Fashion of His Love”
» “The Queen”
» “Just Dance”
» “Love Game”
» “Telephone”
» “Just Dance”
» “Heavy Metal Lover”
» “Bad Kids”
» “Hair”
» “Yoü and I”
» “Electric Chapel”
» “Americano”
» “Poker Face”
» “Scheiße”
» “The Edge of Glory”
» “Marry the Night”

Did you see Lady Gaga’s Born This Way Ball? Let us know what you thought of the show in the comments below!

Christina Ricci Chyler Leigh Ciara Cindy Crawford Cindy Taylor Cinthia Moura Claudette Ortiz

On Friday, November 3, 2006, I left school particularly quickly to meet my uncle at a movie theater nearby. My Uncle Mike was always the cool uncle, who knew good movies, so he had made a point of seeing “Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan” the day it came out. You can probably see why he was the cool uncle.

In the weeks leading up to that day, Sacha Baron Cohen’s first theatrical release was heralded as a wide variety of things, including “sexist,” “offensive” and “the funniest movie of all time.” Mostly unfamiliar with Borat’s previous appearances on “Da Ali G Show,” I wasn’t sure what to expect, but what I got was a new type of comedy that I’m still not sure I was ready for.

When “Borat” first came out, intrepid Kazakhstani journalist Borat Sagdiyev was more than an accent and the collection of catchphrases, like “Var niiccee!” and “How mauch?” that worked their way into frat boy-friendly pop culture references. Borat was shocking and dangerous in a way that most formulaic studio comedies wouldn’t dare to be. Baron Cohen put himself in situation where he realistically could get hurt, but his dedication to the bit instead transitioned each encounter into classic comedy.

Baron Cohen’s new film in theaters this week, “The Dictator,” takes a head-on approach to criticizing both America and the foreign dictatorships it struggles against, but even without a main character seemingly ripped out of the front pages, “Borat” managed to comment on significant issues like the country’s attitudes towards foreigners, racism and homophobia in a hysterically subversive way. Most of the laughs in “Borat” live and die with the audience’s tolerance of awkward situations and the decimation of unspoken social agreements.

Though “Borat” hasn’t necessarily aged well in the collective cultural memory?many now consider it a comedic fad along the lines of “Napoleon Dynamite”?but separated from that current standing, Baron Cohen’s first major release remains his finest with his brand of brutally honest comedy still as biting as ever.

Call them “cult classics.” “Guilty pleasures.” “Comfort movies.” We all have a mental rolodex of flicks that may not be terribly popular but, for one reason or another, they resonate in a very special way. Maybe you saw it at the right moment. Maybe you just see gold where everyone else sees feces. Whatever the case, these are the special favorites that you keep stashed away for sick days. These are some of ours. Tell us about your Sick Day Stash picks in the comments or on Twitter!

Tags borat, Sacha Baron Cohen, Sick Day Stash, the dictator

Bridget Moynahan Britney Spears Brittany Daniel Brittany Lee Brittany Murphy Brittany Snow Brittny Gastineau

Usher sat down for an exclusive “MTV First” interview about his hotly anticipated upcoming release, Looking 4 Myself, his unconventional album-listening experience with the off-Broadway show “Fuerza Bruta” and to give fans a first listen to the Myself track “Twisted” featuring Pharrell. He told MTV News’ Sway Calloway the song is a “nostalgic record” that reflects the album’s ambitious aim to represent the variety of musical experiences that have impacted the R&B superstar.

” ‘Twisted’ is more of a nostalgic record, so when you think about the classic R&B record, we managed a way to modernize it, even though that’s very relevant,” the singer said. “You hear records like Cee Lo, you hear Bruno Mars and also Andre 3000, and that sound is very relevant in this time. So this was kind of our way to tie it all together and give you something different that you probably wouldn’t normally get from me.”

Adapting current sounds and making them his own is a theme Usher is bringing in earnest to Looking 4 Myself and also reflects his philosophy of how to stay in the game. The star released his self-titled debut in 1994, when he was just 16, and has gone on to sell over 65 million records worldwide and score nine #1 songs and six more top 10 hits.

As for how he’s managed to stay on top for so long, Usher revealed that it’s important to never be insular when it comes to music. “Life is a workout, man, it’s like a treadmill, and you gotta be with it, you gotta just stay with it,” he said. “For me, I’ve had the fortunate ability to always be mindful of other things and other people. I’m not so caught up in what I’m doing that I can’t be cognizant of what other people enjoy. … Now, I think music should be used as a channel to really allow people to have different experiences. So, this album is all about bottling up those different experiences.”

The connecting tissue that’s given Usher the ability to explore world music ? from full-on dance tracks like his new single “Scream” and his collaboration with David Guetta, “Without You,” to more classic R&B slow jams like “Climax” and the old-school spare drum beat of “Twisted” ? while delivering cohesive records has been his voice, which he said brings “the essence of soul and emotion” to each record.

“All of my career is kind of an unveiling, an unfolding story, and it ain’t done. There’s so much more that I’m going to do, so much that I’ve now just been interested in and been introduced to,” he continued. “I just want that experience of having this very monogamous relationship with entertainment and acting in a way where I can really, really focus and become better.”

Usher’s commitment to tackling the changing face of music head-on and forging new roads in entertainment as he matures ? he is currently training for a Sugar Ray Leonard biopic ? is the key to his success, he said, concluding, “It’s all about evolution for me.”

Share your review of “Twisted” in the comments below!

Jennifer Morrison Jennifer ODell Jennifer Scholle Jennifer Sky Jenny McCarthy Jessica Alba Jessica Biel

As expected, Justin Bieber’s new single “Boyfriend” has made an impressive debut. After dropping last Monday, the song has sold 520,000 downloads in its first week.

The number is particularly meaningful since it places him at #2 in all-time first-week singles sales. Flo Rida’s track “Right Round,” featuring a then up-and-coming Ke$ha, has the Biebs beat, according to Hits Daily Double. Flo’s track sits at #1 with 636,000 units moved. Other big sellers include the Black Eyed Peas’ “Boom Boom Pow” with 465,000 in downloads (#3), and Mother Monster herself, Lady Gaga’s “Born This Way” selling 447,000 (#4).

Not only are fans gobbling up the single, but his real-life girlfriend, Selena Gomez, has given the song two thumbs up. “Is it my ring tone? No. I didn’t even know you could make it a ring tone,” Gomez told E! News. “It is a great song.”

Bieber is hardly resting on his laurels. The teen star is back in the studio working on Believe. He explained on Twitter that the album, for which “Boyfriend” is the lead single, will go there. “Here making music addressing the past and the rumors, clearing it all up in the music. Im putting it all out there on this album. #BELIEVE,” he tweeted.

He also tweeted out silly videos of himself acting goofy on mock-up sets of the “Boyfriend” video, which he shot last week. In one, he stands in front of a green screen of icy land and in another he stands in front of a green screen of a fireplace.

Of course, Bieber already shared that there really will be fire and ice in the video. “The concept of this video, I mean it’s not like a steady concept,” he explained to MTV News on the Cali-based set in between shots. “It’s not like ‘Justin follows this girl to this spot.’ No, it’s a bunch of amazing scenes: Like a fire scene, we have an ice scene.

“It’s kind of like bouncing back and forth,” he said. “And then there’s scenes of me and just a bunch of girl dancers, and just some great shots, great artistic shots, great shots of me smiling. It’s fun.”

Brittany Snow Brittny Gastineau Brody Dalle Brooke Burke Brooke Burns Busy Philipps Cameron Diaz

Hip-hop’s premier music festival is back. On Tuesday, Guerilla Union held a press conference to reveal its lineup of hip-hop all-stars for Rock the Bells 2012. Freestyler extraordinaire Supernatural delivered the list of performers one-by-one with an impromptu rap, rattling off names like Wiz Khalifa, Kid Cudi, Nas, J. Cole and Mac Miller, as well as veteran acts like Missy Elliott, Timbaland and Bone Thugs-N-Harmony.

Lupe Fiasco’s name also appears on the festival’s flyer, but on Wednesday morning (May 16), the Chi-Town lyricist tweeted that despite what was printed, he would not be in attendance this year. “Not doing Rock The Bellz…thats a typo fam and friends…,” he wrote.

For the first time in nine years, Rock the Bells will expand its daylong festival to two days. The first show will take place August 18 at the NOS Events Center in San Bernardino, California. Last year’s three-stage setup forced fans to choose between their favorite acts, who would often perform simultaneously. “We had quite a few complaints about Mobb Deep fans having to choose between Mobb Deep and Nas,” Guerilla Union boss Chang Weisberg said as an example. “We tried to deliver three stages, but it didn’t work out. So the correction? Two stages, two days, one event.”

RTB will hit the Shoreline Amphitheatre in Mountain View, California, on August 25 and 26 and then the PNC Bank Arts Center in Holmdel, New Jersey, on September 1 and 2. Coincidentally, the East Coast show falls on the very same weekend as Jay-Z’s recently announced Made in America multi-genre music festival in Philadelphia. Hov promises close to 30 eclectic acts in the fields of rock, hip-hop, R&B, Latin and dance music. The Made in America lineup hasn’t been announced yet, but already, the RTB bill is ripe with diverse rap talent. 2 Chainz, Tyga, Kendrick Lamar, Slick Rick, E-40, Too Short and A$AP Rocky will all be in attendance.

The announcement event wrapped up with performances by DJ Quik and Bone Thugs, who took the stage and rocked a few of their many classics, leaving fans ready for the main course this summer. Fans should check RockTheBells.net for venue and ticket information.

Eve Fergie Foxy Brown Freida Pinto FSU Cowgirls Gabrielle Union Garcelle Beauvais

Hip-hop’s premier music festival is back. On Tuesday, Guerilla Union held a press conference to reveal its lineup of hip-hop all-stars for Rock the Bells 2012. Freestyler extraordinaire Supernatural delivered the list of performers one-by-one with an impromptu rap, rattling off names like Wiz Khalifa, Kid Cudi, Nas, J. Cole and Mac Miller, as well as veteran acts like Missy Elliott, Timbaland and Bone Thugs-N-Harmony.

Lupe Fiasco’s name also appears on the festival’s flyer, but on Wednesday morning (May 16), the Chi-Town lyricist tweeted that despite what was printed, he would not be in attendance this year. “Not doing Rock The Bellz…thats a typo fam and friends…,” he wrote.

For the first time in nine years, Rock the Bells will expand its daylong festival to two days. The first show will take place August 18 at the NOS Events Center in San Bernardino, California. Last year’s three-stage setup forced fans to choose between their favorite acts, who would often perform simultaneously. “We had quite a few complaints about Mobb Deep fans having to choose between Mobb Deep and Nas,” Guerilla Union boss Chang Weisberg said as an example. “We tried to deliver three stages, but it didn’t work out. So the correction? Two stages, two days, one event.”

RTB will hit the Shoreline Amphitheatre in Mountain View, California, on August 25 and 26 and then the PNC Bank Arts Center in Holmdel, New Jersey, on September 1 and 2. Coincidentally, the East Coast show falls on the very same weekend as Jay-Z’s recently announced Made in America multi-genre music festival in Philadelphia. Hov promises close to 30 eclectic acts in the fields of rock, hip-hop, R&B, Latin and dance music. The Made in America lineup hasn’t been announced yet, but already, the RTB bill is ripe with diverse rap talent. 2 Chainz, Tyga, Kendrick Lamar, Slick Rick, E-40, Too Short and A$AP Rocky will all be in attendance.

The announcement event wrapped up with performances by DJ Quik and Bone Thugs, who took the stage and rocked a few of their many classics, leaving fans ready for the main course this summer. Fans should check RockTheBells.net for venue and ticket information.

Jennifer Gimenez Jennifer Love Hewitt Jennifer Morrison Jennifer ODell Jennifer Scholle Jennifer Sky Jenny McCarthy

Lady Gaga lives to provoke and push the envelope. But not everyone is up for her antics. The “Americano” singer has been forced to cancel her sold-out June 3 “Born This Way Ball” show at the 52,000-seat Gelora Bung Karno stadium in Jakarta, Indonesia after Islamic hard-liners and conservative lawmakers said her sexy costumes, suggestive dance moves and “vulgar” style could corrupt the nation’s youth.

According to the Associated Press, a spokesperson for the national police said on Tuesday (May 15) that the permit for the show has been denied after religious conservatives worried that the concert could undermine the nation’s moral fiber. Some of the critics actually threatened to use physical force to prevent Gaga from getting off her plane. Though Indonesia is a secular state, it has the world’s largest population of Muslims and a small extremist fringe of religious leaders has been more vocal in recent years.

“She’s a vulgar singer who wears only panties and a bra when she sings and she stated she is the envoy of the devil’s child and that she will spread satanic teaching,” said Salim Alatas, the Jakarta head of hardline Islamic Defender Front (FPI), according to Reuters. “This is dangerous.”

Local police worried that they might not be able to guarantee security at the show and suggested to national police that the permit for what was to be Gaga’s biggest gig on her current Asian tour be pulled. Every seat at the Karno stadium had been sold, with half of them going in the first two hours.

The AP reported that permits for shows are typically issued three weeks before concerts in Jakarta, so it is not uncommon for tickets to be sold well ahead of receiving a final permit. Gaga’s Asian tour started last month and the Indonesian flap is not the first bump she’s faced along the road. Gigs in South Korea? were 18-and-over because conservatives in that country also raised objections over the concert’s content.

Jennifer Aniston Jennifer Gareis Jennifer Garner Jennifer Gimenez Jennifer Love Hewitt Jennifer Morrison Jennifer ODell

Full disclosure about my love for “Twilight”: I don’t so much love the books and movies as much as I completely and totally adore the franchise’s loyal, enthusiastic, entertaining fans. Really it’s their passion and dedication that keeps me interested in the whole thing as we inch closer and closer to the release of the final film, “Breaking Dawn – Part 2.” That’s why I’ve decided to dedicate this week’s “Twilight” Tuesday to one of the many groups of fans with whom I’ve become acquainted over the last few years, Kristen Stewart’s Hot Bodyguard, more specifically, the three lovely ladies who birthed the creative and entertaining concept: Lynsey Jacob, Sarah Morrill and Jennifer Kelley.

“Kristen Stewart’s Hot Bodyguard” is a Facebook group dedicated to, you guessed it, Kristen Stewart’s hot bodyguard. The origin of their popular group (3,000 members and growing!) can be traced to first glimpses of said bodyguard during the “Eclipse” press tour, followed by an in-person encounter at Stewart’s NYC promotion for “Welcome to the Rileys,” and then an excellent bit of brainstorming during a walk to the subway that begot the term “HBG” (Hot Bodyguard) and the Facebook page. Since then, the ladies have kept close tabs on their man via photos, fellow fans and making the occasional trip to a major event. (I was lucky enough to meet Jacob, Morrill and Kelley at such an event, last year’s “Breaking Dawn – Part 1″ premiere.)

“The goal is always to get a wave,” Jacob told MTV News of the most memorable aspects of their HBG sightings. “It’s exciting. Another one that always cracks me up is watching all of the tweets about HBG when there’s an event going on. When he wasn’t at the Kids’ Choice Awards, people were freaking out. And these tweets are from around the world! Half the time it’s in another language.”

“I actually really enjoy making graphics and fun little [themed] pictures for the page,” Morrill added. “I also designed the shirts that we made for the ‘Breaking Dawn’ premiere last year and have already started working on some ideas for this year’s shirts and other swag. Other than that, it’s always cool to see how excited the fans get when we post new pictures or videos of HBG, especially because I’m just as excited to see them as they are! We will be representing Team HBG to its fullest at the ‘Breaking Dawn – Part 2′ premiere in L.A. in November and are excited to meet new fans and see some old ones from the premiere last year.”

One thing to point out about these ladies is that they don’t take themselves too seriously. Yes, they are dedicated fans, but they also just want to continue to have fun with the concept.

“When Stephenie Meyer grabbed a hold of our HBG heads on a stick and took photos with them, that was so cool,” Jacobs recalled of the author embracing their “fan art” at last year’s premiere. “We were always worried that people would think we were crazy instead of just creative fans, but overall, the page and the whole concept has been really well-received.”

“My dream for the group is for it to continue for as long as possible, maybe even until a gray-haired HBG is beating away the paparazzi with his cane in order to protect Kristen,” Morrill joked. “Truthfully, when we started this page a year and half ago, we never could have imagined what it would become. People around the world now refer to Kristen Stewart’s bodyguard as “HBG.” We did that. Stephenie Meyer knows who we are. Kristen mentioned our page in an article for British GQ last year. The awesome folks at MTV think we’re cool. It really doesn’t get much better than that! The only thing I could imagine that would put a cherry on top of this entire experience is to one day be able to change the group’s profile picture to one of the three of us with Kristen and ‘HBG.’

Check out everything we’ve got on “The Twilight Saga: Breaking Dawn – Part 2.”

For young Hollywood news, fashion and “Twilight” updates around the clock, visit HollywoodCrush.MTV.com.

Abbie Cornish Adriana Lima Adrianne Curry Adrianne Palicki Aisha Tyler Aki Ross Alecia Elliott

As the 2012 MTV Movie Awards rapidly approach, there are a few big questions on everybody’s mind: will “The Hunger Games” beat out reigning champion “Twilight” for Best Movie? Will “Harry Potter” finally get the recognition the film deserves? Can anybody win Best Kiss over Robert Pattinson and Kristen Stewart? You may be thinking, “MTV, it’s your movie awards, why are you asking us?” Because YOU have the power!

Your votes decide which movies and their stars take home the Golden Popcorn and this year’s biggest stars are urging you to raise your voice. Along with Kristen Bell, Liam Hemsworth, and Anna Kendrick, Chris Evans wants you to rise up and tune in to the power of the popcorn! And have you seen “Avengers”? Trust us, you don’t want to mess with Captain America himself.

Who will you vote for? Sound off in the comments and on Twitter!

Tags 2012 MTV Movie Awards, anna kendrick, chloe moretz, chris evans, elizabeth banks, kristen bell, Liam Hemsworth, Video

Amanda Swisten Amber Arbucci Amber Brkich Amber Heard Amber Valletta America Ferrera Amerie

Marvel fans are well aware after the end credits of every one of the comic company’s movies will be a small scene alluding to the next film. Following “The Avengers” fans were introduced to Thanos, one of Marvel Universe’s most important villains. Well, guess what? According to “Prometheus” writer Damon Lindelof, “Battleship” followed suit.

YAHTZEE! We’re just kidding with you, but wouldn’t that be fun? We’re kind of hoping it happens now. “Battleship” director Peter Berg needs to pull an “Avengers”-style re-shoot and add it to the end credits. Or actually, change Yahtzee to Candy Land and we’re on board.

With “Battleship” releasing in theaters this Friday the big question is: Who will say the board games’ classic tagline? Zach Braff weighed in on his preference writing, “I hope Rihanna’s the one who gets to say ‘You sunk my battleship.’”

MTV News recently caught up with the singer who said she was “intimidated” by her role in the action film. “I was walking into this as an amateur ? a complete amateur. I didn’t know anything,” she said. ” I was a wreck, just like, scared to sh–.” Maybe she was nervous because she had to carry the film’s most anticipated line?

Personally, Liam Neeson gets our vote for the phrase. As Admiral Shane he’s in a high place of naval power, plus he has the booming voice to project the line amidst a raging alien war.

Will you see “Battleship” this weekend? Who do you think says, “You sunk my battleship”? Let us know in the comments and on Twitter!

Tags damon lindelof, Zach Braff

Ashanti Ashlee Simpson Ashley Greene Ashley Olsen Ashley Scott Ashley Tappin Ashley Tisdale