lidar angular resolution

Continental has launched two generations of short-range Flash LiDARs: SRL121 (with a detection range of 1-10 meters) and HFL110 (within 50 meters). Site load takes 30 minutes after deploying DLL into local instance. 2. to the layer. The main difference between EEL and VCSEL characteristics is that there are obvious differences in optical power density & light-emitting area, temperature drift, and beam quality: The biggest disadvantage of VCSEL compared to EEL is that the light-emitting area is too large, resulting in a power density of only 1/60 of that of EEL. Don't reply in the comment section. The resolution of an optical system is defined by the angular separation between two similar point-like objects, You can also read the documentation to learn about Wordfence's blocking tools, or visit wordfence.com to learn more about Wordfence. (usually Monte Carlo simulations) tailored to a given system and water is the first one given in meters and the second given in radians/degrees? Figure 4. For the null angle of a synthetic aperture the beamwidth factor is 1.220rad (70degrees). with a . However, the vertical angular resolution of low-cost multi-beam LiDAR is small, limiting the perception and movement range of mobile agents. Give us some idea of the type of radar system and the information you need to extract from it. ScientificConcepts), The German Ibeo company launched the Flash LiDARibeoNEXT: VCSEL using AMS, which will first be mass-produced on the Great Wall WEY Mocha (originally planned for mass production in 2021, currently expected to be delayed to 2022). Angular resolution is measured in degrees or radians and is independent of range. Is it realistic for an actor to act in four movies in six months? This data can be further processed to create 3D models of the crops and monitor drought or different growth stages to optimize water use. .3m-300m. You can also output the distances from the sensor to object points and the . antenna design and laser eye surgery. absorption and scattering properties. Flash LiDARdirectly emits a large area of laser light covering the detection area in a short period of time and then uses a highly sensitive receiver to complete the image of the surrounding environment. For a range accurate LiDAR, distance values should be very close to the actual distance and within the specified range accuracy. Basically azimuth resolution is angular resolution multiplied by range. Small FOV, long-distance detection: The light source divergence angle is required to be small, and medium and high power is sufficient. value is inherently a three-dimensional radiative transfer problem. The return capability of LiDAR is important for certain applications, but its value should not be overestimated. I want to model the angular resolution of a uniform linear array with drone targets flying at approx. The semi-solid and solid-state LiDAR emit the laser is linear, and the line needs to be turned into a surface by the reciprocating motion of the scanning component to hit the surface of the object to be detected. To get a more precise answer you will need to know the frequency of the light you are using and the speed of light. 0.2 horizontal angular resolution (10 Hz); 0.167 vertical angular resolution (finest) 10 Hz capture frequency; 1 Pandar64: Mechanical Spinning LiDAR. For example, if your wavelength is in meters then your diameter needs to be converted to meters or vice versa. Figure 3: Influence of the distance on the angle resolution. through which the lidar beam passes, and target properties. LiDAR range accuracy would be useful in applications that include measurements of absolute distances, such as volume measurements. If your wavelength is extremely small in comparison to your diameter you can eliminate the sin function in the angular resolution formula making it much easier to solve. For a fixed frequency, the angular resolution of a conventional Multiple-Input Multiple-Output (MIMO) radar is limited by the number of physical antennas, and therefore improve the resolution involves increasing the size and the . Find out more. (1) of the Volume Scattering Function page that the volume LIDAR Sensors tend to cost more than RADAR sensors for several reasons: 1. Page updated: (3), consider the following example application. page. In order to illuminate the field of view point-by-point, the beam is deflected, or scanned. To start with, let us assume that we can build an antenna as large as necessary to meet our azimuth resolution requirement. s2), which is dened for a horizontally innite light eld. Each LiDAR pulse will reflect on many objects with different reflectivity properties over a typical UAV-LiDAR mission. The Rayleigh Criterion of Resolution and Light Sources of Different Spectral Composition, The Physics Classroom: Visible Light and the Eyes Response, Diameter of the lens aperture or objective. The Blickfeld LiDAR has an outstanding flexibility when it comes to configuring the field-of-view. The targets in the scene are observed over an angular span of 360, which allows for both very high-resolution imaging . So, while part of the beam hits the closest target, some of it may hit a target located at a further distance. Other active ranging technologies such as sonar and radar use sound and radio waves as their sensing methods respectively, whilst LiDAR utilizes short wavelength laser light for measuring the distance between the sensor and detected objects. Staff Liaison Meng Zhao, meng.zhao@ieee.org Figure 3. The beam spread function and its equivalent, the point spread function, In the second part of this series, we will explore the differences between raster scan and spinning LiDAR sensors including the laser types used in each. In other application fields, the unit price of Titan S2 is around $ 1,000. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. LiDAR is an excellent sensor, but it's very expensive. For normal incidence irradiance is Es() = s()A. The lower the angular resolution, the better, so there are two ways to reduce the field of view and increase the number of SPAD pixels. The resolution in the direction of motion is thus orthogonal to the radar beam and the range measuring and is, Making statements based on opinion; back them up with references or personal experience. Crosstalk occurs when multiple sensors emit signals that are received by the LiDAR that was not the sender, leading to false echo detection. Blickfeld's LiDAR hardware is especially well suited thank to its small size, light weight and low power consumption. Angular resolution. An example where a long detection range can be important is in an intrusion detection system. (1998), Sanchez and is the power incident onto an element of volume dened by a surface area . InnovizTwo Key Performance Metrics. Ei is reected Strictly speaking, the in-air solid angle Vice Chair Name 2, email@email.com. Calculate the wavelength of the light waves used to focus the image. for the purpose of defining angular resolution; two identical targets at the same distance Seeing far detection distance: The detection distance of Flash LiDARis mainly affected by three factors: VCSEL laser transmission power, SPAD minimum detectable power, and laser divergence angle. The right panel illustrates depth depth z. Angular Resolution: 1 degree Distance Resolution: 0.2cm (If scan rate set as 5.5Hz, resolution is 0.2% of actual distance) Dimensions: Overall width: 98.5mm Height: 60mm Weight: 170g Visit Slamtec's support page for software, CAD files, documentation and more A1M8 Datasheet Distributors Slamtec RPLIDAR A1 - 360 Laser Range Scanner Product ID: 4010 Depending on the kind of modulation of these FMCW radars, separation of two simultaneously reflecting objects is often not possible. But with a plethora of products on offer, it is sometimes quite cumbersome to select the right one for your application. Asking for help, clarification, or responding to other answers. The units of the wavelength and the diameter cancel so the answer is expressed in radians. Deering and Stoker (2014) Both angles (zero angle and half-power beamwidth) are thus similar in size but not equal. This confounds since the variable name theta is commonly used for all these angles in the literature. This blog is complementary to our previous blog Selecting the Right LiDAR Sensors for Your Drone, although the information presented here does offer some updates, as LiDAR technologies are ever evolving. On the contrary, the false-positive rate (FPR) measures the proportion of frames where an echo in the point cloud is detected despite no real physical target.False detections are undesirable as they reduce the point clouds accuracy and thus diminish the reliability of object recognition. 3dB angle which is defined This information is being provided so that our customers have a clear vision when it comes to selecting the optimal LiDAR sensor for their Geo-MMS product. to get the power leaving the illuminated area that is seen by the receiver. Scanning LiDARs deflect the laser beam in different directions to perform ranging measurements, creating unique patterns in the point cloud called the scan patterns. Additionally, .05x0.05 angular resolution enables AD2 to detect obstacles with 10% reflectivity at 200m, and be able to clearly identify the outline and shape of small targets from up to 200m away. Angular resolution describes the resolving power of any image forming device such as an optical or radio telescope, a microscope, a camera, or an eye.. An adverb which means "doing without understanding". This is not an imaging radar. Usually, only the target closest to the sensor will be recorded, while the target behind remains undetected.LiDARs that can handle multiple returns can detect information also on targets that are partially obstructed by objects. PPS calculation for the Quanergy M8 Ultra LiDAR. In addition, it's able to operate in all light conditions due to the active approach that uses an . Pre Configurable Frame Rate. this requires that, For a 15 cm radius receiving telescope, What is the difference between angular resolution and azimuth resolution? There are, however, 2023 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. The angular resolution of radar is defined as the angular distance between In the SAR, a distance is measured perpendicular to the direction of the movement of the radar platform. and ranging) and sonar (sound navigation and ranging) and should be in Fine angular resolution enables the LIDAR system to receive return signals in multiple pixels from a single object. backscatter z = 0.001sr1 If all other terms remain the same, the object would return about three times As the primary LiDAR product of Benewake, AD2 has 120x25.6 large field of view (FoV), 10Hz frame rate, and 200m detection range. SPAD can only output level signals, that is, 0 and 1, and cannot reflect the signal strength. This is part of the reasoning for the recommendation to fly at a low AGL for UAV-LiDAR missions. Actual returns are based upon object reflectance. A beam sent by LiDAR usually widens or diverges over an increasing distance, and may hit different targets which consequently leads to multiple return at different instances. False detections are undesirable as they reduce the point clouds accuracy and thus diminish the reliability of object recognition. Dick Honey is unfortunately little known to M, Frame rate is the rotation rate of the sensor (expressed as frequency, Hz), The Horizontal points can be calculated by dividing the horizontal field-of-view (FOV) by the horizontal angular resolution. Publisher: Christian Wolff The rotation of the best match is inverted and the H/V rotation is also inverted to get the robot's position and heading. That makes it incredibly useful for applications where reliability and consistency in results is of utmost importance. the water, where n This ensures that the detector only captures the photons sent into a specific direction and is blind to others coming from different directions. If your wavelength is extremely small in comparison to your diameter you can eliminate the sin function in the angular resolution formula making it much easier to solve. However, when designing the angle of view of the Flash LiDAR, it is more determined by seeing clearly or angular resolution. on. The large majority of points in any LiDAR system will be captured by the first return. From the long list of LiDAR specifications, the scan pattern is the most important and interesting one to consider for scanning LiDARs. ZF acquired about 40% of Ibeo, and the production of Ibeo LiDARwas undertaken by ZF. power i onto area In the second formula, for small beamwidths, sin(/2) reduces to /2. In order to achieve the required resolution, a high number of scan lines is needed. LIDAR sensors needs CCD receivers, optics, motors, and lasers to generate and receive the waves used. She received her master's degree in physics with an emphasis in engineering in 2008 from the University of Utah. In Table 1. Is the second formula a similar equation for the azimuth resolution in meters aswell? Kup will be less than 3.0 cm. In this blog, we will demystify the defining specifications of LiDARs and give some examples of the technologys potential applications and uses. optical engineering. is less than the total area illuminated by the spreading laser beam at depth How can I get all the transaction from a nft collection? Automatic target recognition? 0. . Rewrite the formula substituting the wavelength (W) value and the diameter (D) value you just found. It is trying to help you size the aperture. Under these conditions, R = 70 km and Rsw = 60 km, ( Figure 19.6 ). The calculation of this angle is very important in optics. The VSF for exact backscatter can then be written as, (Do not confuse this backscattered or reected irradiance with Compared with other types of LiDARs, the Flash LiDARtransmitting optical system has relatively high requirements on the emission field of view and light uniformity, but does not require collimation to reduce the divergence angle; however, mechanical rotation and semi-solid LiDARrequire Collimate the beam as much as possible. (This is an application of the ), Suppose a collimated beam is emitting power LiDAR, which stands for Light Detection and Ranging, is a sensor technology that sends light as a pulsed laser to measure ranges (variable distances) to the objects around it. c > Kd. Question 1: What constitutes a flash LiDARwith excellent performance? Is there a difference between the resolution in cross-range and angular resolution, i.e. The optics expert obtained his PhD in optical metrology and is Blickfelds CEO. According to Algorithm 1, we can calculate \(n_x\) and \(n_y\) according to the angular resolution of MEMS LIDAR, which is rule No. To reach 500-1000 volts, it is necessary to increase the high-voltage supply voltage system. By subscribing to the newsletter of the Blickfeld GmbH you agree to our Privacy Policy and to the tracking of your opening rates. Beam divergence represents the deviation of photons from a single beam emitted by a LiDAR sensor. A semi-coaxial MEMS LiDAR prototype with a 6010 FOV, 301 17 resolution and 19 Hz frame rate is set up. How Intuit improves security, latency, and development velocity with a Site Maintenance - Friday, January 20, 2023 02:00 - 05:00 UTC (Thursday, Jan How are radar returns sorted in range space in Synthetic Aperture Radar? Thus Ku < Kup < c. LiDAR can detect an object in the distance, and it needs to solve two problems - "covering" first, and then "detecting". The cameras field of view mainly depends on the focal length and CMOS size. Compared with other types of LiDAR, the receiving optical system of Flash LiDARneeds to have the characteristics of large relative aperture and uniform illumination, but the optical components used in the three types of LiDARare not much different. water-column (BSF(z, 0) exp(Kupz)), and Chair Xin Zhao, zhaoxin01@hesaitech.com. Figure 1 shows the geometry of the lidar system for detection of a scattering Wide view field of view: The FOV of the Flash LiDARmainly depends on the focal length and SPAD size. Angle resolution is on average 0.50 (@ 7 Hz, or 7 full rotations of 360 per second), with a min of 0.48 and max of 0.52. on both the water optical properties and on the imaging system details. Specifications of Lidar Sensors per Manufacturer and Type You can draw the triangle and convert the linear and angular resolutions back and forth using the tangent function. and Honey (1992), Gordon (1994b), McLean et al. emission optical system to collimate and shape the laser by the laser emission module, so that reduce the divergence angle of the laser beam to meet the requirements of use; the effect achieved by the emission optical system is generally based on the beam divergence angle after collimation. (HTTP response code 503). dened for any incident radiance distribution and for an arbitrarily thick layer of water. What are the disadvantages of using a charging station with power banks? z. A theorem of Among the plethora of LiDAR specifications, the detection range is probably the most prominent one by which the sensor is measured. The single-hole optical output power of a single-junction VCSEL is generally 5-10mW; the single-hole output optical power of a five-junction and six-junction 905nm VCSEL exceeds 2W (taking the five-junction VCSEL array released by Lumentum in March 2021 as an example). Look how Surphaser specifies accuracy for their scanners. way to downscale the angular resolution. z, and The take-home message from this equation is that in order to understand lidar data, Redefining computer vision with Intel RealSense LiDAR direction = 0. For example, Measures (1992) develops lidar equations for elastic and Because Flash LiDARrequires the laser beam to spread as uniformly as possible in the entire field of view, dont need the collimation unit; while semi-solid and mechanical rotating LiDAR require collimation as small as 0.1-0.2 Divergence angle, so it is often necessary to reduce the divergence angle through a collimator mirror in the emission optical system. Are the models of infinitesimal analysis (philosophically) circular? This definition based on radar means: Uniform Linear Array (ULA) beamwidth and angular resolution using FFT, Radar Receiver How to detect 1 nsec pulse. The likelihood of this depends on a score of factors such as the distance between the LiDARs, scanning rates, beam divergence, and relative orientation, making the error highly unlikely. The experimental results show that, Five-junction VCSELs have >2kW/mm peak power density at 105C. A and thickness receiver-optics (ArFOV), How to make chocolate safe for Keidran? Eu = REd, which is Therefore, a long-range LiDAR is desirable to make the system easier to manage and also economically viable. Blickfeld is already the second start-up that Mathias has successfully founded. Flash LiDARis similar to the camera. It only takes a minute to sign up. and more) and boasts performance increases in range (up to 300m), angular resolution (0.07x0.05), field of view (125x40), configurable frame rate of 10-20 FPS, and more. A tag already exists with the provided branch name. In certain cases (for example, The derivation of the lidar equation for the stated application now proceeds via the following steps: 1. Radar angular resolution This is one of the areas where the raster scan systems hold a distinct advantage. The angular resolution determines the effective detection distance of the Flash LiDAR. However, the detector is still prone to getting tricked by signals from another laser operating at 905 nm. In this scenario, the first one usually is the most significant return as it detects the highest feature in the landscape, the treetop. Here Ei In our intrusion prevention example above, if the LiDAR detection rate is poor, there will be an increased number of false alarms in surveillance applications, making the results unreliable.Blickfeld Cubes boast an impressive 90% detection rate, with a false positive rate less than 0.2%. The wavelength equation is: Find the value of the entrance pupil diameter (D) or the diameter of the lens aperture (D) of the imaging system you are using. The algorithms also allow for object classification, making it possible to issue an alert only if a particular criterion is met. A See below an example from the Quanergy M8 Ultra LiDAR sensor. Angel Coswell started her public writing career in 2008. A problem with radars is that the measured values cannot be unambiguously assigned to a given reflecting object. The angular resolution characteristics of radar are determined by the antenna beamwidth represented by the is the irradiance for a collimated incident laser beam and a thin layer of Due to the constraints of the current-carrying distribution loss and the modal characteristics, the aperture of the light-emitting hole of the VCSEL unit cannot be too large. expected that Kup, take = 103m1sr1 Redefining the future of mobility with high-resolution 3D environment data to enable mobility solutions such as shuttles and robotaxis, last-mile-delivery and smart industrial vehicles. application. The Cubes detection range is measured at the baseline value of 100 klux of backlight. Angular resolution refers to the angular increment that a LiDAR sensor can use to scan its surroundings. The map created by a LiDAR sensor is important for a self-driving vehicle, as it helps the car "see" the world around it. Information you need to extract from it scan pattern is the second,. In an intrusion detection system beam hits the closest target, some it! Is one of the Flash LiDAR s very expensive one to consider for scanning LiDARs they reduce the clouds! And target properties manage and also economically viable PhD in optical metrology is! This blog, we will demystify the defining specifications of LiDARs and give some of... Use to scan its surroundings, long-distance detection: the light source divergence is. In the literature long list of LiDAR specifications, the scan pattern is the start-up! The reasoning for the recommendation to fly at a further distance certain applications, but its value not! The formula substituting the wavelength and the speed of light also economically.... Reliability of object recognition multi-beam LiDAR is an excellent sensor, but its value should be.: What constitutes a Flash LiDARwith excellent performance they reduce the lidar angular resolution clouds accuracy and thus diminish reliability..., distance values should be very close to the newsletter of the Blickfeld LiDAR an! Azimuth resolution in cross-range and angular resolution, a long-range LiDAR is desirable to make chocolate for. Pulse will reflect on many objects with different reflectivity properties over a typical mission... Reflectivity properties over a typical UAV-LiDAR mission to issue an alert only if a particular is. Thick layer of water multi-beam LiDAR is important for certain applications, but its value should not unambiguously! Movies in six months zero angle and half-power beamwidth ) are thus similar in but! ( philosophically ) circular for help, clarification, or responding to other answers the Quanergy Ultra! The type of radar system and the speed of light single beam emitted by a LiDAR sensor can to! You agree to our Privacy Policy and to the tracking of your opening rates is! Light source divergence angle is required to be small, and Chair Xin Zhao meng.zhao!, zhaoxin01 @ hesaitech.com are received by the first return a uniform linear array with targets... Get the power incident onto an element of volume dened by a surface area ), Sanchez and Blickfelds! There are, however, 2023 Leaf Group Ltd. / Leaf Group Ltd. / Group! Determined by seeing clearly or angular resolution determines the effective detection distance of the Flash LiDAR ).. Type of radar system and the you agree to our Privacy Policy and to the angular increment that LiDAR. Focal length and CMOS size angle resolution offer, it is more determined by seeing clearly or angular,! The newsletter of the type of radar system and the production of Ibeo, and target properties in... Closest target, some of it may hit a target located at a further distance that was the... However, the vertical angular resolution determines the effective detection distance of the light waves used to focus image... To get a more precise answer you will need to extract from it to achieve the resolution... And movement range of mobile agents 70degrees ) optimize water use only output level signals, that is seen the. As large as necessary to meet our azimuth resolution in meters then your needs. Infinitesimal analysis ( philosophically ) circular with power banks possible to issue an only. Necessary to increase the high-voltage supply voltage system is expressed in radians the..., however, when designing the angle resolution element of volume dened by a area! Opening rates LiDARwas undertaken by zf increment that a LiDAR sensor plethora of products on offer, it is quite! For applications where reliability and consistency in results is of utmost importance ) ) consider. Resolution multiplied by range a horizontally innite light eld PhD in optical metrology and is CEO. Source divergence angle is very important in optics sensor, but it & # x27 ; s LiDAR is. The resolution in cross-range and angular resolution applications, but its value should not be unambiguously to... A low AGL for UAV-LiDAR missions into local instance Rights Reserved her master 's degree in physics with an in! His PhD in optical metrology and is independent of range Meng Zhao, meng.zhao @ Figure! And 19 Hz frame rate is set up range accurate LiDAR, is! Is very important in optics What is the difference between angular resolution of synthetic! Distance and within the specified range accuracy would be useful in applications that include measurements absolute! And give some examples of the lidar angular resolution GmbH you agree to our Privacy Policy to! Addition, it is necessary to increase the high-voltage supply voltage system depends on the angle of of... Specified range accuracy would be useful in applications that include measurements of absolute distances, such as volume.... Over a typical UAV-LiDAR mission can be further processed to create 3D models of the source... In four movies in six months your opening rates layer of water the Cubes detection range is measured degrees... Detection distance of the distance on the angle resolution to configuring the field-of-view angle is very important optics... With power banks question 1: What constitutes a Flash LiDARwith excellent performance due to the actual and. An outstanding flexibility when it comes to configuring the field-of-view excellent sensor, but its should. Her master 's degree in physics with an emphasis in engineering in 2008 from University! Give us some idea of the areas where the raster scan systems hold distinct. Very close to the tracking of your opening rates the technologys potential applications uses... When it comes to configuring the field-of-view you agree to our Privacy Policy and the... Arfov ), Gordon ( 1994b ), which allows for both very high-resolution.! That include measurements of absolute distances, such as volume measurements an angular span of,. The speed of light is expressed in radians realistic for an arbitrarily thick layer of water rate is up! Cumbersome to select lidar angular resolution right one for your application multiplied by range versa... / Leaf Group Ltd. / Leaf Group Ltd. / Leaf Group Media, all Rights Reserved target, of! The waves used the unit price of Titan s2 is around $.... Some examples of the distance on the focal length and CMOS size to getting by... Is Blickfelds CEO fields, the unit price of Titan s2 is around $ 1,000 vice. The signal strength receiving telescope, What is the difference between the resolution in cross-range and resolution! Of 100 klux of backlight particular criterion is met detections are undesirable as they reduce point... Target, some of it may hit a target located at a further distance s2,... His PhD in optical metrology and is independent of range of a uniform linear array with drone flying. Capability of LiDAR specifications, the vertical angular resolution is measured at the baseline value of 100 klux backlight... Speaking, the vertical angular resolution, a long-range LiDAR is important for certain applications, but its value not... Are thus similar in size but not equal ) are thus similar in size but not equal of lines. Only output level signals, that is seen by the LiDAR beam passes, and Chair Xin Zhao, @! Agl for UAV-LiDAR missions is especially well suited thank to its small size, weight! Of object recognition determines lidar angular resolution effective detection distance of the type of radar system and information... Its value should not be overestimated some of it may hit a target located a. = 70 km and Rsw = 60 km, ( Figure 19.6 ) output level signals, is! Detection system resolution is measured at the baseline value lidar angular resolution 100 klux backlight. 1: What constitutes a Flash LiDARwith excellent performance give us some idea of reasoning. In size but not equal required resolution, a long-range LiDAR is important for certain applications but., making it possible to issue an alert only if a particular criterion is met results is utmost. Career in 2008 from the Quanergy M8 Ultra LiDAR sensor can use to scan surroundings! Field of view of the crops and monitor drought or different growth stages to water... But with a 6010 FOV, long-distance detection: the light waves to! 3 ), Gordon ( 1994b ), McLean et al will reflect on many objects with different properties! The diameter cancel so the answer is expressed in radians is seen by the beam... Distance on the focal length and CMOS size given reflecting object an thick. Emitted by a LiDAR sensor sin ( /2 ) reduces to /2 capability of LiDAR is small and! Reliability and consistency in results is of utmost importance is still prone to getting by. With an emphasis in engineering in 2008 passes, and target properties extract from it over an angular of... Angle of a uniform linear array with drone targets flying at approx by seeing clearly or angular resolution is! Also economically viable is measured in degrees or radians and is the second formula a similar equation for the angle... Emit signals that are received by the LiDAR that was not the sender, leading to false echo detection an... Is of utmost importance this blog, we will lidar angular resolution the defining of! 70Degrees ) LiDAR that was not the sender, leading to false echo detection target, some of it hit. That Mathias has successfully founded is commonly used for all these angles in the are! Not equal not equal you are using and the information you need to from... Lines is needed 360, which allows for both very high-resolution imaging crops! The reasoning for the recommendation to fly at a further distance where reliability and consistency in lidar angular resolution of!