Dual frequency gps android

Dual-Frequency GPS vs Single-Frequency GPS: What’s the Difference?

Fitted with a Broadcom BCM chip, the Xiaomi Mi 8 provides up to decimeter-level accuracy for location-based services and vehicle navigation, the company said. Until now, mobile location-based applications have been powered by single-frequency GNSS receivers whose location accuracy is limited to a few meters. However, in recent years GNSS systems have been launching satellites broadcasting signals on new frequencies to open up new possibilities. According to the company, users of the Xiaomi Mi 8 and future models with dual-frequency GNSS will benefit from better positioning and navigation experience in urban environments. The numerous Galileo satellites broadcasting E5 make this improvement available for users all around the world. In addition, the simultaneous use of two frequencies reduces other sources of error, such as those due to the ionosphere, and the frequency diversity is more robust to interference and jamming. In addition to making existing applications more accurate, the enhanced position precision offered by dual-frequency GNSS will also create opportunities for new applications in areas such as augmented reality, vehicle navigation and mapping. We will continue to pursue innovation for everyone to enjoy. The launch of the first dual-frequency GNSS smartphone, together with the opportunities offered by the availability of GNSS raw measurements in Android, creates exciting opportunities for the geolocation community, the company said. Access to raw measurements opens the door to algorithms once restricted to more advanced GNSS receivers. This, in turn, allows users to fully benefit from the differentiators offered by Galileo. Recognizing these opportunities, in the GSA engaged with academia and industry in the areas of navigation and positioning to innovate around this new feature as part of a GNSS Raw Measurements Task Force. If you enjoyed this article, subscribe to GPS World to receive more articles just like it. Name required. Email required; will not be published. Follow Us. Your behavior appears to be a little unusual. Please verify that you are not a bot. Dual-frequency GNSS smartphone hits the market. Leveraging Galileo for increased accuracy According to the company, users of the Xiaomi Mi 8 and future models with dual-frequency GNSS will benefit from better positioning and navigation experience in urban environments. Post a Comment Click here to cancel reply. Terms of Use Privacy Policy. This site uses cookies to offer you a better experience, analyze site traffic, and serve targeted advertisements. By continuing to use this website, you consent to the use of cookies in accordance with our privacy policy.

Dual-Frequency GNSS – An important location feature your phone is probably missing


We expect that for professional applications that need precision positions, a dedicated system that employs a custom GNSS chipset and purpose-built applications will continue to be the right solution. A range of new use models and applications will be enabled by consumer mobile phones with technology that improves positioning performance. Then we show the position performance achievable using precision engine with measurements from a dual-frequency GNSS chipset targeted for the cellular handset market. This class of device is expected to be integrated into consumer cellular devices on the market within the next 1 to 2 years. We tested various devices including the Nexus 9 which provides phase data and various other Android devices that implement the new API. Most devices tested do not support phase data; of the few devices tested that do provide phase data, all except the Nexus 9 implement GNSS power duty cycling. This is a mode where the GNSS chipset is only active for a fraction of each second to reduce power consumption. This results in cycle slips each epoch, which makes carrier-phase processing for real-time kinematic RTK unusable. During the testing a wide range of performance across devices was observed. The units were located in a clear environment less than a meter apart. Deep fades are present, most likely caused by deconstructive multipath. Figure 1. Before attempting to position with observables from Android devices the measurement quality was analyzed. One of the devices tested was a Samsung S7 device. However, the phone implements power duty cycling so after a short period of operation the duty cycling mode was enabled which resulted in a cycle slip on the phase every epoch. To derive an improved position from this class of device pseudorange and Doppler can be fed into a code-phase positioning engine. Fortunately, the Doppler provided by the device is of reasonable quality as can be seen from Figure 2. Figure 2. In this simple analysis measurements from a single high elevation satellite were analyzed. The Doppler is plotted along with the differenced pseudorange converted into L1 cycles. It can be seen that as expected the Doppler has much lower noise and so can be used in a pseudorange smoother. A simple way to view the pseudorange noise is to subtract the carrier phase from the pseudorange.

What is the Xiaomi Mi 8’s dual frequency GPS?


Location services are among of the most useful applications on your phone, not only helping navigate your way but also allowing several apps to tailor features and services based on your location. A lot of these applications and other features like the AR-based Live View in Google Maps require high accuracy in your position. While the traditional Global Satellite Navigation Systems GNSS use radio waves of a single frequency to communicate with artificial positioning satellites and may not be very accurate, dual-frequency GNSS are gaining attention for their higher accuracy. The older, single-frequency GNSS can be inaccurate by 5m. Among the various reasons for this inaccuracy are multipath errors which are caused as a result of GPS signals bouncing off of rigid objects and undergoing a distortion. Dual-frequency GPS rectifies multipath errors by using two signals instead of just one satellite to determine the locations. Therefore, dual-frequency GNSS can estimate your location accurately down to the one-tenth of a meter. The dual-frequency signals are named after the positioning systems they rely on. For instance, GPS signals in the U. We tested some of the recently launched phones for dual-frequency GNSS support and discovered that the following support the feature:. While dual-frequency GNSS was has been limited to flagship devices, we may soon see it on mid-range and even entry-level devices, since Qualcomm announced support for the L5 signal along with the standard L1 signal on new chipsets including the Snapdragon G, Snapdragonand Snapdragon These may, however, not be compatible with Galileo. If you wish to learn more, we have a detailed explainer on dual-frequency GNSS written by Jack and you should give a read. Want more posts like this delivered to your inbox? Enter your email to be subscribed to our newsletter. Tushar's love for tinkering with different forms of consumer tech brings him to this front. Besides technology, he likes to keep a tab on the political climate and trade bouts that make things expensive, and in turn, peeve him. Order the Samsung Galaxy S20 at Amazon. XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer? Terms of Service. Hosted by Leaseweb. March 11, am Comment Tushar Mehta. Download QR-Code. Developer: barbeauDev. Price: Free.

Dual-Frequency GNSS – An important location feature your phone is probably missing


The Mi 8 is the first phone to boast dual frequency GPS navigation technology. This small detail is often overlooked on the specification sheet in favor of processors and cameras, but it brings a number of exciting potential possibilities. It has been in phones and other products for years. All of these services are similar, in so far as they provide location information, but they operate over a number of different frequency bands from 1,MHz to 1,MHz. Technically each of the navigation systems listed above is compatible with multi-frequency GNSS, but not all of the satellites in orbit support multiple frequencies, particularly legacy GPS satellites. Being the newer system, Galileo is perhaps best positioned to offer dual frequency GPS with its satellites. In a nutshell, this is a similar technology to GPS or other navigation technologies but allows devices to scale up through a wider number of frequency bands for better accuracy. While your typical smartphone will rely on a single frequency receiver, multi-frequency smartphones like the Mi 8 use two or more for better location accuracy. Dual frequency GPS is particularly potent in urban environments, where signal interference and obstruction is more common. Right out of the gate, users should notice a much faster time to first fix. This means there will be less waiting around for Google Maps or other apps to first find your location. Current single frequency smartphone solutions offer an accuracy of about 5 meters. Dual-frequency chipsets boast decimeter level accuracy — just a tenth of a meter. Dual-frequency GNSS offers accuracy down to just tenths of a meter, compared to 5 meters currently. When we think navigation app, we typically think Google Maps. It's the one most people recommend. It also happens to get frequent updates. Google has been really on top of navigation especially over the last …. For smartphones, high accuracy tracking allows for better placement in augmented and virtual reality spaces. This could range from accurate store overlays using an AR camera app to turn-by-turn navigation through a mall. Outside of smartphones, high accuracy navigation could be especially useful for smart city planning and mass IoT with long battery life. Inclusion in semi-autonomous, self-driving cars and other vehicle safety features seem like a perfect fit, as does a cost-effective implementation in consumer-level drones. Dual frequency GPS location tracking and navigation might not be a headline-grabbing technology, but its adoption will enhance common smartphone use cases like navigation, and open the door to new ideas that rely on high accuracy. With more compatible satellites up in orbit and more power-efficient receivers now on the market, this technology will likely head to more smartphones and other products in the near future. Robert Triggs. Comments Read comments. You Might Like. Fitbit Charge 4 is here with built-in GPS and an aggressive price point. Huawei has found an alternative to Google Maps on new smartphones. Get the Android Authority app on Google Play. Sunday Giveaway. Samsung Galaxy S20 Plus international giveaway! April 5, Join our Newsletter Get the very best of Android Authority in your inbox. News, reviews, deals, apps and more. Your source for all things Android!

What is the Xiaomi Mi 8’s dual frequency GPS?

The introduction of a new generation of mass-market chips based on multi GNSS dual frequency measurements, already being commercialized and integrated in smartphones by major manufacturers, is contributing to a new level of positioning accuracy in the mass-market location-based services. Today, we are assisting to a proliferation of high accuracy applications on smartphones, thanks to the availability of dual frequency measurements along with the capability to process GNSS raw measurements on Android devices. Here the authors address a new level of sub-meter positioning accuracy, before unimaginable without professional grade equipment, and now accessible to everyone on smartphones, to people on all budgets. While a new generation of mass-market chips using multi GNSS dual frequency measurements provides great potential, there are still some hardware limitations to overcome, most notably related to the poor quality of the GNSS antenna integrated in smartphones. The selection of this dual frequency combination is particularly appealing for two main reasons:. This is very important for multipath rejection as it will be shown further in this article. It is important to stress that the final positioning accuracy in mass-market devices is not only driven by GNSS measurements, either single or dual frequency. All these ingredients contribute to the fused location and its ultimate accuracy. The tests results shown in this article have been conducted in a variety of configurations and scenarios, including static, pedestrian and vehicular setups. The quality of the raw measurements has been evaluated through code multipath analysis and cycle slips occurrence probability. Similarly to other authors Riley et aliathe development kit enabled the comparison of the standalone performance of the chip against its integrated smartphone version. The main differences in the test setup between this evaluation kit and the smartphone are the following:. It can be fed with raw measurements coming either from the chipset evaluation kit connected to the professional grade antenna or from smartphones, accepting as input either broadcast or final orbital and clock products MGEX GBM. The evaluation kit was used as a simple source of dual-frequency measurements for static and kinematic users. Live static data were collected in open sky conditions. One test was performed near the ESTEC football pitch, with the evaluation kit connected to a geodetic-grade antenna installed on the roof of the van, while the smartphone was placed on the van dashboard. The satellite signal power levels are set to values corresponding to open sky conditions in AWGN channel model and then decreased by steps of 2 dB per sec. The football pitch is mainly an open sky area, with only a slight building shadowing on its west side. The average walking speed was 3. Lever arms to the reference anten. The campus presents some obstructions in a few points of the route due to trees and surrounding buildings and the environment can generally be considered mild. The main contributor to the accuracy of the pseudorange measurements is definitely the multipath error. In the case of Galileo E5a and GPS L5 as well the error instead results much smaller and confined between few meters amplitude max 3 meters in the case shown as example. Such combination is a code minus carrier observation where the ionospheric error contribution is removed by the combination of carrier phase measurements from L1 and L5, as described in the following equation:. N represents the unknown ambiguity. During a continuous period of tracking satellite i, N is a constant as long as no cycle slips have occurred. Therefore, the multipath plus noise estimate. To compute instead the multipath error on L5, the first frequency is L5 and the second frequency is L1. The same methodology has been applied to all the satellites visible during the static tests T. In these cases, the variance of the measurements is higher and there is a degradation of performance with respect to the same chipset working with a professional grade antenna, demonstrating the impact of the planar inverted F antenna PIFA assumed to be mounted on the smartphone and of a noisier environment probably due to internal interference in the phone. In the case of carrier phase measurements, the multipath combination cannot be used to determine the accuracy. A double difference combination approach has been used, where the difference of carrier phase measurements from two satellites and two different receivers are combined. Carrier phase measurements from the GNSS RF simulator and the evaluation kit were double differenced for cycle slips detection. In the case of a zero-baseline test, double differencing allows to cancel errors from the ionosphere, troposphere and satellite clock biases. Since a static test was simulated, the position component of the double differences is constant and can be ignored.

How to get one-meter location-accuracy from Android devices (Google I/O '18)



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