PerbedaanRadar, Sonar & Lidar v RADAR ( Radio Detection and Ranging) adalah suatu sistem gelombang elektromagnetik yang berguna untuk mendeteksi, mengukur jarak dan membuat map benda-benda seperti pesawat terbang, berbagai kendaraan bermotor dan informasi cuaca (hujan) menggunakan gelombang radio. Pernahkahmendengar istilah lidar? Secara teknis, lidar mirip sekali dengan radar. Kepanjangan dari lidar adalah Light Detection and Ranging, sedangkan radar adalah Radio Detection and Ranging. Radarastronomi berbeda dari astronomi radio di kedua adalah pengamatan pasif dan mantan satu aktif. Sistem radar telah digunakan untuk berbagai studi tata surya. Transmisi radar baik dapat berbentuk pulsa atau kontinu. Vay Tiền Nhanh. LiDAR, Radar, and Sonar are the modern remote sensing techniques used by various professionals to collect and analyze data. The main difference between these technologies is they use different mediums to send signals to and from the objects and then analyze the time taken to measure the distance between the transmitter and the objects. Radar transmits radio waves, LiDAR emits light pulses and Sonar utilizes sound are more of the differences between the three remote sensing Remote Sensing1. Uses laser beamsLiDAR technology uses light pulses or laser beams to determine the distance between the sensor and the object. The laser travels to the object and is reflected back to the source and the time taken for the laser to be reflected back is then used to calculate the Measures precise distance measurementsBecause of the nature of the laser pulses, LiDAR is mostly used to measure the exact distances of an object. The laser pulses travel at the speed of light which increases the accuracy of the Measures atmospheric densities and atmospheric currentsLiDAR technology can be used to measure atmospheric densities of various components such as aerosols and other atmospheric gases. This is because the pulses are more accurate and have a shorter wavelength that can be used to acquire accurate Used in obtaining 3D images with high resolutionLiDAR technology is capable of creating high-resolution images of an object at any surface and this is why it is popularly used in mapping and other topographical uses. Based on the speed of the laser pulses from LiDAR sensors, the data is returned fast and with accurate It is adversely affected by smoke, rain, and fogUnlike RADAR technology, LiDAR pulses are adversely affected by atmospheric weather conditions such as dense fogs, smoke, and even rain. The light pulses will be distorted during flight and this will affect the accuracy of the data It has a higher measurement accuracyUnlike RADAR, LiDAR data has a higher accuracy of measurement because of its speed and short wavelength. Also, LiDAR targets specific objects which contributes to the accuracy of the data LiDAR is cheaper when used in different applicationsLiDAR technology is cheaper when used in large-scale applications. This is because it is fast and saves a lot of time and it is also not very labor-intensive unlike other methods of data Data can be collected quicklyBecause of its speed and accuracy of the laser pulses from LiDAR sensors, the data can be collected fast and with utmost accuracy. This is why LiDAR sensors are used in high capacity and data-intensive It does not have geometric distortionsLiDAR sensors are highly accurate and are therefore not affected by geometric distortions. The data collected will be precise and accurate and will map the exact location of the object in the It can be integrated with other data sourcesLiDAR data can easily be integrated with other data sources such as GPS and used in mapping and calculation of distances. This can also be applied in forest mapping and other remote sensing Remote Sensing1. Uses Electromagnetic wavesRADAR technology uses electromagnetic waves or radio signals to determine the distance and angle of inclination of objects on the It can operate in cloudy weather conditions and during the nightUnlike LiDAR, RADAR technology is not affected by adverse weather conditions such as clouds, rainfall, or It has a longer operating distanceRADAR technology has a longer operating distance although it takes a longer time to return data regarding the distance of the Cannot detect smaller objectsIt does not allow the detection of smaller objects due to longer wavelengths. This means that data regarding very tiny objects on the surface may be distorted or No 3D replica of the objectIt cannot provide an exact 3D image of the object due to the longer wavelength. This means that the image will be a representation of the object but not an exact replica of the object’s Determines distance from objects and their angular positionsApart from the distance from an object, RADAR technology can also provide the angular positions of objects from the surface, a characteristic that cannot be measured by RADAR measures estimated distance measurementsRADAR technology does not give the exact accurate measurements of distance and other characteristics of the object because of the Radar beam can incorporate many targetsA RADAR beam can have several targets at the same time and return data on several objects at the same time. However, this may exclude smaller objects within the target Radar may not distinguish multiple targets that are close togetherRADAR technology cannot distinguish multiple targets within a surface that are closely entangled together. The data may therefore not be RADAR takes more time to lock on an objectRADAR, unlike LiDAR pulses, travels at a slower speed which means more time is needed to lock onto an object and return data regarding the Remote Sensing1. Uses sound wavesSonar stands for Sound Navigation and ranging. It transmits sound waves that are then returned in form of echoes which are used to analyze various qualities or attributes of the target or Used to detect underwater objectsSonar is mainly used to detect underwater objects because the sound waves can penetrate the water depths to the bottom of the It is affected by variations in sound speedSound travels slowly in freshwater than in seawater. This means that the variations in the speed of sound may affect the return echoes which may also have an impact on the data or attribute of the Mostly used to find actual sea depthBecause of its unique capabilities of penetrating seawater, sonar is mainly used to calculate the depth of the sea because it is fast and Is not affected by surface factorsThe sound waves are not affected by the calmness or the roughness of the water surface. They can penetrate even tides and still get the necessary data It has adverse effects on marine lifeSound waves from sonar have adverse effects on marine life such as whales that also depend on sound Sonar generates a lot of noiseThe sound waves from the transmitters usually generate a lot of noise that also have an effect on the marine life that live deep Passive sonar does not require a transmitter and a receiverUnlike active sonar that transmits with the help of a transmitter and also relies on a receiver, passive sonar does not transmit. It listens without transmitting9. ScatteringActive sonar may lead to scattering from small objects as well as the sea bottom and surface which may cause Causes decompression sicknessSONAR may cause decompression sickness that may be fatal. What is Lidar? Pernahkah mendengar istilah lidar? Secara teknis, lidar mirip sekali dengan radar. Kepanjangan dari lidar adalah Light Detection and Ranging, sedangkan radar adalah Radio Detection and mulanya, prinsip dasar radar dibangun oleh seorang ahli fisika Inggris bernama James Clerk Maxwell pada tahun 1865, yang dikenal dengan teori Maxwell. Setahun kemudian, seorang ahli fisika asal Jerman bernama Heinrich Rudolf Hertz berhasil membuktikan teori Maxwell mengenai gelombang elektromagnetik dengan menemukan gelombang elektromagnetik itu sendiri. Istilah radar baru dipopulerkan sejak tahun 1941, meskipun teknologi radar sudah dikembangkan selama beberapa tahun sebelum Perang Dunia II. Apakah tujuan pengembangan radar? Tidak lain adalah untuk menentukan jarak antara dua tempat yang berbeda tanpa mengukur secara langsung. Prinsip pengukuran radar sangat sederhana, yaitu dengan menggunakan gelombang radio yang diarahkan ke suatu target, kemudian target memantulkan gelombang radio tersebut sehingga kembali ke asalnya. Waktu tempuh pantulan gelombang radio tersebut dapat dihitung, sehingga jarak antara sumber gelombang dengan target dapat diperoleh, yaitu setengah waktu lidar Gelombang cahaya light yang digunakan dalam teknologi lidar merupakan gelombang elektromagnet, yang memiliki komponen elektrik dan komponen magnetik. Gelombang ini kurang lebih sama dengan gelombang radio, namun berbeda dalam panjang gelombang. Gelombang radio secara umum memiliki rentang frekuensi kurang dari 3000 Hz, atau memiliki panjang gelombang berkisar 0,1 mm hingga km, sedangkan gelombang cahaya yang digunakan dalam teknologi lidar umumnya memiliki panjang gelombang 532 nm, 355 nm dan 1064 nm, serta beberapa panjang gelombang tunggal lainnya di dalam rentang cahaya tampak. Kecepatan rambat antara gelombang radio dan gelombang cahaya adalah sama. Lidar dapat berupa instrumen yang dioperasikan pada ground based station, misalnya lidar untuk mengukur jumlah aerosol dan ozon di udara secara vertikal. Selain itu, lidar dapat ditempatkan pada satelit yang fungsinya untuk melakukan pemetaan beberapa komponen penyusun atmosfer, juga dapat ditempatkan pada pesawat udara air borne lidar yang umumnya digunakan untuk pemetaan topografi permukaan lidar untuk pemetaan Aplikasi lidar yang paling dikenal oleh masyarakat secara luas adalah untuk pemetaan geologi, yaitu dengan cara menerbangkan peralatan lidar menggunakan pesawat terbang UAV ataupun drone. Lidar jenis ini dapat membuat citra tiga dimensi 3D lebih cepat dan lebih baik, serta memiliki akurasi jarak yang lebih tepat dibandingkan dengan kamera RGB biasa. Dengan menggabungkan teknik fotogrametri UAV dan pemetaan lidar maka dapat dilakukan survei model permukaan, gambar udara geofisika yang dikoreksi secara geospasial, model bangunan 3D, peta kontur, survei volumetrik, dan lain-lain. Banyak manfaat yang bisa diambil dengan keberhasilan pemetaan lidar, misalnya dalam pengelolaan dan pemetaan kehutanan, pemodelan banjir dan polusi, kartografi, arkeologi, dan perencanaan jaringan kemudian diolah secara post processing menggunakan perangkat lunak GPS post processing. Tentunya, metode ini bukanlah metode yang sempurna karena ketelitian yang dihasilkan oleh lidar sangat variatif, bergantung pada kondisi 1. Freya, radar deteksi dini Jerman zaman Perang Dunia II. Radar Freya mulai digunakan tahun 1939 sejumlah lebih dari 1000 buah. Jarak jangkauan radar adalah 200 km dan azimuth 360 derajat. Radar Freya berhasil mendeteksi pesawat musuh dari jauh sehingga membantu pertahanan Jerman dalam PD-II. Namun demikian, Inggris berhasil memanipulasi dengan membuat sejenis jammer sehingga radar Freya seolah-olah mendeteksi pesawat dalam jumlah besar padahal sesungguhnya hanya sedikit pesawat saja sumber Wikipedia.Sistem lidar yang digunakan untuk pemetaan adalah lidar yang dapat melakukan scanning dalam satu sumbu horizontal. Sistem ini ditempatkan pada pesawat terbang atau UAV yang dilengkapi dengan Global Positioning System GPS dan Inertial Navigation System INS. INS adalah sistem navigasi yang mampu mendeteksi perubahan geografis, perubahan kecepatan, serta perubahan orientasi dari suatu benda. Sistem GPS diperlukan untuk penentuan posisi wahana terbang secara 3D terhadap sistem referensi tertentu. Semua informasi yang diperoleh selamaGambar 2. Prinsip kerja lidar. Sinar laser dihasilkan oleh pembangkit laser atau transmitter dan diarahkan menuju obyek, kemudian dipantulbalikkan dan diterima kembali oleh teleskop receiver. Pantulan ini kemudian mengalami pengolahan secara digital menjadi sinyal yang dapat diterjemahkan. Gambar 3. Prinsip dasar lidar untuk di LAPAN Sebagai lembaga penelitian keantariksaan, Lembaga Penerbangan dan Antariksa Nasional LAPAN khususnya Pusat Sains dan Teknologi Atmosfer PSTA juga mengoperasikan lidar di Bandung. Lidar ini dikhususkan untuk mengeksplorasi kandungan uap air secara vertikal hingga ketinggian tropopause. Dalam pengoperasiannya, lidar menghasilkan berkas laser pada panjang gelombang 532 nm cahaya hijau sehingga ketika dioperasikan pada malam hari dan cuaca cerah masyarakat di sekitar dapat melihat berkas cahaya hijau yang mengarah tegak lurus ke atas. Lidar yang dioperasikan saat ini sebenarnya merupakan generasi kedua dari lidar yang dimiliki PSTA. Sebelumnya, PSTA juga pernah memiliki lidar dengan kekuatan power yang lebih besar, serta field of view yang lebih lebar, sehingga cahayanya menjadi lebih terang. Sayangnya, lidar generasi pertama ini sudah tidak dapat beroperasi karena kerusakan yang tidak dapat diperbaiki. Selain itu, sistem lidar ini juga sangatlah rumit. Lidar ini merupakan hibah dari kerjasama LAPAN dengan beberapa lembaga penelitian negara Jepang. Seperti apa bentuk sinyal keluaran lidar? Jangan membandingkan Raman lidar dengan lidar untuk pemetaan topografi, karena lidar ini sifatnya statis dan hanya mengamati di satu lokasi pengamatan. Sinyal keluaran dari lidar hanyalah berupa backscattering ratio dan depolarization ratio. Backscattering ratio dihubungkan dengan jumlah komponen atmosfer yang memantulbalikkan sinyallaser, sedangkan depolarization ratio Sassy berhubungan dengan ketidakbulatan komponen pemantul tersebut. Partikel-partikel yang berbentuk bulat akan menghasilkan pemantulan sempurna sehingga tidak terjadi depolarisasi atau nilai rasio depolarisasinya adalah nol. Contoh partikel pemantul yang berbentuk bulat adalah tetes air, sedangkan yang berbentuk tidak beraturan misalnya kristal es pada suhu di bawah nol derajat celcius. Dalam perkembangan tingkat lanjut, lidar juga diaplikasikan untuk mengukur distribusi vertikal suhu atmosfer menggunakan prinsip pergeseran panjang gelombang, atau Raman Shifting yang berasal dari molekul-molekul nitrogen di lapisan-lapisan atmosfer. Selain itu, lidar juga diaplikasikan untuk mengukur konsentrasi ozon yang dikaitkan dengan fenomena penipisan lapisan ozon stratosfer. Teen MagazineGambar 4. Prinsip kerja Raman Lidar yang dioperasikan oleh PSTA. Pembangkit laser akan menghasilkan sinar laser dengan panjang gelombang 532 nm, yang umumnya disebut sebagai second harmonic generation SHG. Sinar laser ini akan dibelokkan tegak lurus ke atas menggunakan cermin pemantul, dan akan berinteraksi dengan komponen-komponen penyusun atmosfer misalnya uap air dan aerosol melalui proses-proses fisika, yaitu penyerapan, pemantulan, serta pembiasan, dan mengikuti hukum pemantulan Raman. Selanjutnya, sinar laser yang telah mengalami hamburan balik akan diterima kembali oleh sebuah teleskop dan kemudian diarahkan menuju tabung penguat atau photomultiplier tube agar menghasilkan sinyal listrik. Sinyal ini kemudian diperkuat kembali menggunakan preamplifier dan dihitung menggunakan photon 3. Lidar di LAPAN, dikhususkan untuk memantau lapisan uap air hingga ketinggian tropopause. Lidar ini merupakan hibah dari Universitas Nagoya dan sebelumnya telah digunakan pada penelitian umur udara air age di Biak. Selain uap air, lapisan aerosol troposfer bawah dan planetary boundary layer pun dapat diamati menggunakan skala internasional, penggunaan lidar dalam mengeksplorasi atmosfer telah dilakukan lebih dari 20 tahun yang lalu. Salah satu keberhasilan fenomenal lidar adalah memantau debu vulkanis letusan Gunung Pinatubo tahun 1991 yang dilakukan oleh negara Jepang. Di Mauna Loa, debu vulkanis teramati menggunakan lidar hingga 4 tahun sejak letusannya. Hingga saat ini, negaranegara maju seperti Jepang, Inggris, Amerika Serikat serta Eropa telah menggunakan lidar dalam jumlah yang sangat banyak, namun Indonesia baru mengoperasikan hanya satu buah lidar saja, yang merupakan hibah dari negara Jepang. Akankah lidar di PSTA mampu beroperasi hingga bertahuntahun yang akan datang?Penulis Saipul Hamdi Submarines use radar to navigate the deep seas. An autonomous vehicle, on the other hand, would use LiDAR. While they both have very similar names and are based on sensors, radar and LiDAR aren’t quite the same. Often, they are pitted against one another. Yet, both are also necessary in the future of automated vehicles. These depend on advanced sensor fusion technology to perceive their surrounding environments and keep occupants safe. This need led to a richer development of two systems used to underpin autonomous vehicle stacks LiDAR vs. radar. Let’s break down the pros and cons associated with each system, starting with explaining what a LiDAR is. What is LiDAR? LiDAR, or Light Detection and Ranging, is a remote sensing tool that uses light to detect how far away objects are from the sensor. By shooting out a pulse of light waves that bounce off surrounding objects, it can capture data that is refracted back to create a three-dimensional, 360° map of the surrounding area. LiDAR sensors are best known for capturing their environment in extreme detail, even better than the human eye depending on weather conditions and time of day. Here’s an example. Radar, or Radio Detection and Ranging, is a type of sensor that uses electromagnetic radio waves to determine the distance, angle, and speed of objects related to the source. These sensors can capture data from much further distances than LiDAR systems, but the resolution of these data is less precise. In fact, their results aren’t detailed as LiDARs, whose level of detail enables building exact 3D models of objects. LiDAR vs. Radar for Autonomous Driving 5 Key Differences As the similarity of these two acronyms suggest, LiDAR and radar share a nearly identical function in detecting signals and determining ranges based on the information collected. However, the differences between light waves and radio waves provide pros and cons to automated vehicle systems based on Accuracy Performance Wavelength Reach Cost Applications 1. Accuracy How precise is LiDAR vs radar? LiDAR tracks details with remarkable accuracy in three-dimensional space by capturing the position, size, and shape of objects relative to the sensor. When combined with advanced perception software, this LiDAR data can be analyzed from the “point cloud” and classified as objects and obstacles. By scanning the environment thousands of times every second, LiDAR helps AI make complex decisions around the intent of pedestrians, vehicles, and hazards. Radar is better suited for capturing information related to velocity and range. Stuck in a two-dimensional world, it cannot capture the breadth of information that LiDAR systems perceive. This means that in some cases, objects may be falsely identified or fail to be detected. 2. Performance One of the biggest problems previously facing LiDAR systems was their performance in direct sunlight or inclement weather. Because they rely on light waves to capture data, older LiDAR systems could become distorted by raindrops, snow, and fog. Innoviz’s LiDAR systems are resistant to these conditions. Radar does not rely on visual data, and thus performs optimally in all conditions. 3. Wavelength Reach Radio waves have much larger wavelengths than light waves—while they detect signals through the same principles, the wavelength frequency of radar vs. LiDAR gives each system different capabilities. The large wavelength of radio waves allows them to be transmitted at great distances. However, radars in passenger vehicles are limited by the size of the antenna. They can detect signals much further away, but the detail that they capture has low resolution. Light wavelengths are significantly smaller—LiDAR systems can capture details at a much smaller level from distances camera sensors cannot track. However, they do not have the same wavelength reach as radar systems. 4. Cost While LiDAR has clear advantages in terms of safety and performance, companies like Tesla have shied away from the technology completely. This is primarily due to one reason LiDAR’s price point. Radar may be more affordable to everyday consumers, but as LiDAR technology has evolved, the cost gap has narrowed dramatically. Solid-state LiDAR sensors are significantly more affordable and reliable than their predecessors as they have no moving parts. They’re costing hundreds, not thousands of dollars. As innovation continues and manufacturing occurs at scale, LiDAR will continue to grow less expensive. 5. Applications Radar is excellent for adaptive cruise control and monitoring cross traffic, blind spots, and collisions. However, radar cannot capture the breadth of information that LiDAR systems perceive. This means that objects can be falsely identified, or not appear if they are too small. These errors have led to crashes leading to several high-profile lawsuits that have resulted in agencies like the National Highway Traffic Safety Association stressing the need for increased federal regulation over these systems. LiDAR’s ability to precisely capture data makes it the superior choice for features like emergency brake assist, pedestrian detection, and collision avoidance. The granularity of detail vastly outperforms radar- and camera-based technologies. Why LiDAR Fills the Safety Gap for Autonomous Driving With one exception, the majority of autonomous vehicle manufacturers agree that LiDAR systems are the future of the industry. With higher accuracy and resolution than radar, LiDAR achieves the promise of autonomous vehicles a safer world without automotive crashes. Yet even though LiDAR carries significant advantages, radar still has a place in the self-driving cars of tomorrow through sensor fusion. Sensor fusion uses LiDAR, radar, ultrasonic sensors, and cameras in unison to give a complete picture of the environment around an autonomous vehicle. By leveraging multiple types of signals and “fusing” them together, the individual weaknesses of each sensor are negated. Simplified, radar may be used for long-distance hazard detection, LiDAR can detect pedestrians at night, and cameras can read traffic signs, all as part of a unified system. When it comes to autonomous vehicles, radar- and camera-based systems are not sufficient on their own. LiDAR and radar sensors paired together can help overcome what one cannot do on its own. Take Your Vehicle Further LiDAR Technology by Innoviz There are over six million car crashes each year in the United States. The vast majority of these are caused by human error. With LiDAR technology powering autonomous vehicles, needless tragedies like these could soon be a thing of the past. At Innoviz, we are working tirelessly on creating affordable and safe LiDAR systems for vehicles to make a crash-free future a reality for all. Contact our team to learn more about how we are blazing the trail for the safe roads of tomorrow.

perbedaan lidar dan radar