Two methods of spoofer detection, the identification and sourcing of false GNSS signals, have been released by Javad GNSS, using features available for all of its OEM GNSS boards.
Spoofer detection and alarm. This feature then identifies and isolates the spoofer signal, ignores it, and provides a position solution using only valid satellite signals.
Determination of the direction from which the spoofing signals emanate. This can aid in tracking down the actual spoofing source.
Spoofer Detection
With 864 channels and roughly 130,000 quick-acquisition correlators, the Javad GNSS Triumph chip can assign more than one channel to each GNSS satellite, in order to find all the signals that are transmitted with that satellite’s PRN code. If the chip detects more than one reasonable and consistent correlation peak for any PRN code, it concludes that spoofing is present and can the proceed to identify the spoofed signals.
In this case, it uses the position solution provided by all other clean signals (L1, L2, L5, and so on, from all GNSS constellations — GPS, GLONASS, Galileo, Beidou, and mroe) to identify the spoofer signal and use the real satellite measurement. If all GNSS signals are spoofed or jammed, then the system issues an alarm, directing the user to ignore GNSS and use other sensors in an integrated system.
Satellite and Spoofer Peaks
The figure below shows an example of a spoofer signal and a real satellite signal received at a GNSS receiver. These screenshots are from a real spoofer in a large city. The bold numbers are for the detected peaks. The gray numbers represent highest noise, not a consistent peak. A “*” symbol next to the CNT numbers indicate that signal is used in position calculation. Each CNT count represent about 5 seconds of continuous peak tracking.
The first screenshot shows no spoofing is present. The second shows that all GPS satellites are being spoofed.
No spoofer. Only one reasonable peak for each satellite. (Table: Javad GNSS)Table: Javad GNSS
In the above screenshot all GPS satellites have two peaks and all are spoofed. We were able to distinguish the spoofer signal and use the real satellite signals in correct position calculation as indicated by the ”*” next to the CNT numbers.
GNSS Overall View
The following screenshot shows the status of all GNSS signals. The format and the signal definitions are explained below.
Table: Javad GNSS
Tracked: Tracked by the tracking channels and has one valid peak only.
Used: Used in position calculation.
Spoofed: Has two peaks. Good peak is isolated, if existed.
Blocked: Blocked by buildings or by jamming. If jammed, shows higher noise level.
Faked: Satellite should not be visible, or such PRN does not exist.
Replaced: Real signal is jammed and a spoofed signal put on top of it. Because of jammer, it shows higher noise level.
By Oliver Leisten Technical Director, Helix Technologies Ltd.
To attain the 10-centimeter accuracy required for autonomous vehicle positioning within urban multipath propagation conditions, there is a need for a significant upgrade in GNSS antenna performance. The autonomous vehicle application demands excellent antenna performance together with exploitation of the full set of GNSS multi-frequency and multi-constellation system advances to deliver this performance paradigm in the most severe of real-world use scenarios.
Given that an antenna necessarily operates in open fields, it follows that field resonance must be managed to provide predicable performance in diverse use-scenarios. A new antenna developed by Helix Technologies (Figure 1) deploys balanced fields across a cylindrical ceramic dielectric core to constrain the outreach of resonance fields and thereby minimize the interaction with nearby objects. The antenna feed is designed to provide enforcement of balanced operation, which ensures that the antenna resonates predictably and independently of the platform (i.e., the vehicle in the case of autonomous driving). Thus, the operation is not significantly influenced by the mechanical or material properties of the platform or housing. This architecture provides isolation from common-mode signals and protects the GNSS signals from conducted interference.
Figure 1. Features of the hexafilar-turnstile solution for multi-frequency GNSS.
It is challenging to configure a GNSS antenna operating at many frequencies in which the performance at any one frequency is not impaired by mode interactions. Such impairments can have serious consequences for the position accuracy in an urban environment because they adversely affect the cross-polar discrimination: a parameter which is most important for eliminating multipath positioning errors. The architecture of the hexafilar-turnstile antenna has overcome this problem and delivers the circular polarization pattern characteristics illustrated (simulated data) in Figure 2.
Figure 2. Simulated RH circular polarized patterns at GPS L1 (left) and GPS L2 (right).
The figure demonstrates that the antenna is forming cardioid patterns at two frequencies. The 3D graphic is intended to show the omni-directionality and the 2D elevation cuts exhibit the signature cardioid shape which characterize a “spinning-dipole” circular polarization antenna.
It is often suggested that patterns of wide beam-width such as these would not be particularly suitable for positioning in urban canyons where the sky can only be seen in a relatively small solid angle. In fact, the ratio of front-to-back gain is strongly associated with the cross-polar discrimination that is important for position accuracy in urban environments. Patterns of this quality can deliver as much as 30-dB of signal-to-interference advantage in favor of the direct-path satellite signals against signals whose polarization has reversed due to multipath reflection.
Helix Technologies is developing antennas which have two-pole frequency responses that provide two frequencies of optimum cross-polar discrimination that are aligned to the two frequencies of maximum spectral density of an M-BOC or Alt-BOC coded signal, as transmitted by the modern GPS and Galileo satellites respectively. These antennas should be available for test and evaluation in Q2 of 2018.
SuperSurv’s NTRIP solution is being enhanced to adopt more RTCM versions and provide a better GNSS positioning service. NTRIP (Networked Transport of RTCM via internet protocol) is a protocol to send GNSS-related data through the internet, which enables users of differential GPS or network real-time kinematic (RTK) to get correction parameters after connecting to the internet. The correction parameters can be used to calculate a more accurate GNSS location. Supergeo’s product team is developing the support for RTCM 3.1, including Types 1021 and 1023.
The scalable A222 GNSS smart antenna is designed for both agriculture and basic indicate systems markets, as well as other markets requiring flexible positioning. The smart antenna has the flexibility to scale and grow as business expands and can be configured from L1-only to multi-GNSS, multi-frequency and real-time kinematic (RTK). It adds a system component so that tractor and farm equipment manufacturers can deliver their own guidance and control solutions to their customers. Designed to excel in challenging environments, the A222 uses Hemisphere’s Athena RTK engine and is Atlas L-band capable. It is easy to mount and customizable. Its dual-serial, CAN and pulse output options are compatible with almost any industry-standard interface. Because the A222 is Atlas-capable, it has the ability to use the new Atlas AutoSeed technology. Atlas AutoSeed allows users to suspend Atlas use for any period, and upon returning to their last location, AutoSeed rapidly re-converges to a high-accuracy converged position. A222 comes pre-configured with Atlas Basic activated.
Locates mobile devices moving indoors and outdoors
Leveraging ubiquitous LTE signals, the Lite-Touch Architecture calculates positioning in the cloud to efficiently locate devices between indoor and outdoor environments. By offloading computation-heavy location calculations from the device to the cloud, the PoLTE positioning solution makes location positioning available to a wider variety of devices, including those constrained by battery life, memory, processing power, size and cost. This includes IoT-based applications that historically relied on GPS, with its high rate of power consumption, as well as Wi-Fi and Bluetooth with their added size, cost and network complexity.
Enhancements to the SyncServer S600 series of time servers and instruments improve time synchronization over enterprise Ethernet networks and supply timing signals for improved military radar operations and satellite uplink communications. The SyncServer S600 series also meets the timing and synchronization needs of the rapidly evolving networks of enterprise and financial customers, particularly for compliance purposes such as the European MiFID II directive, which specifies highly stringent time accuracy requirements for stock trading systems. The latest release includes support for the IEEE 1588 multiport, multi-profile Precision Time Protocol (PTP), which allows the S600 to operate as an independent grandmaster clock on each Ethernet port — delivering cost savings and network deployment flexibility to customers. This is coupled with a new 10-GbE interface to easily interoperate with a wider variety of network and stock trading topologies.
The HG4930 inertial measurement unit (IMU) is tailored for “straight-out-of-the-factory” integration and use in various non-defense and non-aerospace industrial applications including surveying and mapping, autonomous vehicles and gimbal stabilization. The HG4930 IMU is not classified under an International Traffic in Arms Regulation category; it is free from the burden of an export license for all but a few military-related use cases. The micro-electro-mechanical system (MEMS)-based IMU has been tailored to provide significantly improved gyroscope and accelerometer performance for the environments and use cases experienced by non-aerospace and non-defense users.
The HX-DU2017D is a frequency-hopping OEM modem designed to provide strong anti-jamming and signal receiving capability for complex data-intensive applications. HX-DU2017D is a miniature, dual-frequency, software-selectable 840-MHz and 900-MHz data link modem. It provides power switching of 0.5 W, 1 W and 2 W; 20 ms/30 ms/40 ms/50 ms/ frequency-hopping intervals; and supports point-to-point, point-to-multipoint network. Its full duplex mode ensures secure data transferring and stable long-range communication. The HX-DU2017D also provides short latency of data transmission and communication recovery in millisecond level. It allows fast and secure simultaneous data communication for mission-critical applications, especially in the fields of precision agriculture and UAVs, including unmanned plant surveys, UAV plant protection and automatic mowers. It could be placed on a UAV with its extremely small footprint for tight OEM integration and design flexibility. Meanwhile, its frequency-hopping transmission ensures UAV data security and flight stability.
For small construction, thermal inspections and public safety
The Parrot Bebop-Pro Thermal is a compact quadcopter with two embedded cameras: a stabilized 14-megapixel high-definition front-facing video camera and a FLIR ONE Pro thermal camera. The thermal-imaging camera is positioned in a dedicated module at the back of the drone. Three thermal-imaging setting modes are available: Standard, Dynamic and Hotspot. The Parrot FreeFlight Thermal app innovatively transmits and analyzes images captured by the quadcopter’s cameras. Included is a long-range Parrot Skycontroller 2 remote control.
Pergam gas sensor integrated with carbon-fiber UAV
Pergam gas sensor aboard the Microdrones md4-1000 UAV.
The aerial methane detector mdTector1000 CH4 detects methane gas via a fully integrated aerial package. It has a Pergam gas sensor, mounted and integrated with the Microdrones md4-1000 UAV. In real time users can see aerial shots of detection with the laser sensor. The carbon-fiber-built UAV goes into dangerous areas unsuitable for workers. The mdTector1000 CH4 can be used for natural gas line surveys, tank inspections, gas well testing, plant safety and landfill emission monitoring. The mdCockpit Android app allows users to maintain visualization in flight. A special mdTector app allows users to visualize and present all post-flight data on one map.
Microdrones, www.microdrones.com
UAV tracking antenna
Portable antenna for unmanned or manned aircraft
The Octopus UAV portable tracking antenna enables long-range data transmission and is suitable for unmanned and manned aircraft applications. It has a range of more than 100 kilometers and an integrated pointing algorithm. The GPS location of the aircraft is sent over the Airlink IP datalink and received directly by the tracking antenna, making it operational with any existing unmanned aircraft autopilot system. For a manned aircraft, an existing GPS receiver or dedicated GPS receiver can be used.
Brings high-precision positioning and attitude to small UAVs
AsteRx-m2 UAS receiver.
The AsteRx-m2a UAS GNSS OEM engines provides precise and reliable multi-frequency, all-in-view real-time kinematic (RTK) positioning and heading — along with interference technology — with low power consumption. It features Septentrio’s AIM+ interference mitigation and monitoring system, which can suppress a wide variety of interferers. It is designed to bring high-precision positioning and attitude to any space-constrained application, offering a high update rate and low latency output. The AsteRx-m2a UAS provides plug-and-play compatibility for autopilot systems such as ArduPilot and Pixhawk. Event markers accurately synchronize camera shutter events with GNSS time. The board can be powered directly from the vehicle power bus via its wide-range input. It works seamlessly with GeoTagZ software, providing offline re-processed RTK accuracy without the need for either ground control points or a real-time datalink.
The GPS-TMG-HR timing antennas are designed for Positive Train Control and railroad management, among other markets. They are equipped with high-rejection narrowband filtering to mitigate interference and provide 65-dB rejection of frequencies adjacent to L1 GPS. The GPS-TMG-HR maintains all features of PCTEL’s GPS timing reference platform. The antennas feature a 26-dB amplifier (GPS-TMG-HR-26N) and 40-dB amplifier (GPS-TMG-HR-40N ) and narrowband high rejection filtering to support long-lasting, trouble-free deployments in congested cell-site applications with severe interference around the GPS L1 frequency. The proprietary quadrifilar helix design, coupled with multi-stage filtering, provides superior out-of-band rejection and lower elevation pattern performance than traditional patch antennas.
The GPDF.47.8.A.02 is a ceramic GPS L1/L2 / Galileo low-profile, low-axial ratio, embedded stacked passive patch antenna. It is 47.5 x 47.5 millimeters wide and 8 millimeters thick. It is designed for the highest accuracy centimeter-level tracking in telematics applications for positioning technologies. Typical applicable industries are transportation, defense, marine, agriculture and navigation.
The Autonomy Development Platform provides automakers, truck makers and Tier 1 vehicle suppliers the hardware, software, engineering and integration services they need to accelerate development programs for on-road and off-road autonomous vehicles. By combining customized integration and engineering services with GNSS-inertial positioning technologies, the Autonomy Development Platform advances driverless vehicle development projects at every stage of development and commercialization. The platform delivers a navigation solution that is fully customizable and includes integration and engineering services, field-tested hardware and proprietary software for highly accurate positioning. The solution is capable of working with all sensors, including multiple cameras, lidar, radar and ultrasonic sensors, and with all vehicle types at all stages in the development and commercialization cycle. Also, the technology enables highly accurate assessments of the full 360-degree environment around a vehicle to produce a robust representation, including static and dynamic objects, which is critical for successful vehicle autonomy.
TomTom AutoStream is a map delivery service for autonomous driving and advanced driver assistance systems. The service enables vehicles to build a horizon for the road ahead by streaming the latest map data from the TomTom cloud. TomTom AutoStream ensures that the TomTom map data used to power advanced driving functions is the latest, most accurate available, enabling a safer and more comfortable experience. The map-data stream can be customized based on criteria such as sensor configuration and horizon length. It can stream a wide variety of map data including advanced driver assistance systems (ADAS), attributes such as gradient and curvature, and the TomTom HD Map with RoadDNA. This flexibility allows customers to use AutoStream to power a wide range of driving automation functions.
More satellites, more constellations, more multi-frequency receivers — they all drive greater achievable accuracy. But they also raise the requirements on GNSS antennas because of the stronger impact that possible imperfections might have in the overall error budget for multi-frequency combinations. This analysis of antenna-induced errors in pseudorange code measurements for different antenna feed types helps identify the advantages and disadvantages of such technologies for precise positioning.
By Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
The combination of signals from two frequencies and multiple constellations leads to dual-frequency multi-constellation (DFMC) capabilities, which currently appear to provide improved performance, due to the increased number of satellites available. This leads to better available satellite geometries, but also to the possibility to strongly mitigate ionosphere-related errors, thanks to dual-frequency combination of the ranging signals.
In such scenarios, the hardware-related errors (from satellite and even more from receiver side) will gain a much stronger weight in the overall error budget and should be tackled accordingly.
This article focuses mostly on the receiver antenna contribution, leaving the effects due to the satellite and to the receiver for later work. We will show that the choice of the antenna technology (mostly in terms of the number of feeding points) has a strong impact on the pattern uniformity and therefore on the differential group-delay characteristics over the aspect angle. Optimal performance is demonstrated when using more sophisticated solutions, providing a ground for cost/performance analysis to system engineers of specific applications.
GROUP DELAY PERFORMANCE
Antenna performance in GNSS application is mostly evaluated in terms of antenna gain pattern, noise figure and group delay for code measurement or phase center variation for carrier phase measurement. Gain and noise figure impact on the signal level available at the receiver, while the group delay is a measure of the delay introduced by the antenna hardware to the different spectral components of the signal. The differential group delay (DGD) is
(1)
with φ, f, Az, El being respectively the antenna phase, frequency, azimuth and elevation.
The DGD variation with respect to frequency and aspect angle (that is, elevation and azimuth) actually poses a problem in precision applications: as a matter of fact, if the group delay were constant for all frequencies and all angles of arrival of the signal, no additional error would be introduced in the position calculation, because the group delay term common to all satellites would be encapsulated at the receiver into a user clock offset.
However, group delay can change significantly with respect to aspect angle and frequency, contributing in a different manner for each satellite (due to different angles) and for different signals (due to the different spectral components of each signal), therefore finally producing errors in the pseudorange estimation.
The influence of the DGD on pseudorange measurement error has already been studied in the past and is also taken into consideration in the antenna Minimum Operational Performance Standards (MOPS) for avionic antennas. Empirical studies on the combined effect of antenna group delay and multipath effect on board commercial airplanes have been published recently. However, to our knowledge, the correlation between the antenna intrinsic characteristics (such as gain and phase patterns and smoothness) and group delay behavior has not yet been properly analyzed, leaving a gap in the full understanding of the antenna design impact on the final GNSS receiver performance.
GNSS antennas can be divided into families, according to their geometry (and the related radiation mechanisms): for instance, spiral, helix and microstrip (patch) antennas are quite common in GNSS applications.They differ in achievable bandwidth, size and ease of manufacturing.
Even antennas of the same family can provide different performance, mainly because of the number of feeding points, which are the points where the signal is fed into the antenna.
In order to analyze the relationship between the group delay performance and the antenna properties, we will take into consideration three GNSS antennas of the same family (microstrip patch), having all about half-effective-wavelength size (with the effective wavelength considering the dielectric properties of the substrate material on which the patch antenna is positioned), but with a different number of feeding points. The antennas will be denominated respectively single-feed, double-feed and four-feed antennas.
The single-feed antenna is a square patch, with truncated corners to achieve circular polarization. On the other hand, the double- and four-feed antennas are square patches, having feeds positioned along their x- and y-axis. The feeds are fed progressively: that is, with same amplitude and 0°–90° phases for the double feed and 0–90–180–270° phases for the four feed.
Single-feed antennas are representative of lower cost antennas used in mass-market applications, due to their extreme simplicity allowing for low-cost production. However, their performance exhibits strong cross polarization levels and non-uniform patterns over the azimuth. Dual- and four-feed antennas are more complicated to manufacture and need further hybrid circuits to properly distribute the signal between the different feeding points. However, an increase in the feeding points leads to more uniformity in the radiation pattern and lower-cross polarization and can therefore be expected to improve performance.
Dual-feed antennas are common in applications where a balance between precision and cost is needed, while four feeds are used in high-end applications, such as geodesy and reference stations.
The antennas under consideration here have been tuned to obtain optimal behavior at GPS L1/Galileo E1 band and have been simulated in an electromagnetic solver (Ansys HFSS), with an infinite ground plane assumption, to resemble the large metallic body frame of aircraft structures.
The gain patterns of the different antennas at GPS L1 / Galileo E1 central frequency ( f=1575 MHz) are shown in Figure 1. As discussed earlier, the pattern is not uniform over angle for the single-feed solution. On the other hand, the four-feed antenna shows improved pattern uniformity: the pattern has fewer azimuth and elevation variations, with the two-feed solution providing intermediate results.
Figure 1a. 3D RHCP patterns at f=1575 MHz for single-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 1b. 3D RHCP patterns at f=1575 MHz for a dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 1c. 3D RHCP patterns at f=1575 MHz for a four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Phase patterns for the three antennas are shown in Figure 2. Here again, the one-feed solution exhibits more angular variation than the multi-feed solutions. It is interesting to notice how strong phase variations occur in the same regions where the gain pattern also varies strongly.
Figure 2a. 3D RHCP phase patterns at f=1575 MHz for a single-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 2b. 3D RHCP phase patterns at f=1575 MHz for a dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 2c. 3D RHCP phase patterns at f=1575 MHz for a our-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
When considering the DGD, the frequency dependence of the phase pattern will have to be taken into account, according to Equation (1). To show the DGD variability with respect to the aspect angle, the standard deviation of the DGD over a 20-MHz bandwidth has been calculated (for each azimuth and elevation angle) and is shown in Figure 3, confirming the better behavior of the four-feed antenna.
Figure 3a. 3D standard deviation (calculated over frequency) of the DGD for a) single-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 3b. 3D standard deviation (calculated over frequency) of the DGD for a dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 3c. 3D standard deviation (calculated over frequency) of the DGD for a four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 4 shows the group delay versus frequency and elevation (with different azimuth values being represented by curves with different colors) for the three typologies of antennas: such typology of figure contains all information about DGD variation versus frequency and angle and is first introduced in this article. For comparison, in the RTCA’s 2006 MOPS document for airborne antennas, for the sake of simplicity, either DGD variation versus angle at central frequency or DGD variation over frequency at zenith were considered, hence not fully covering the complete space {Frequency, Azimuth, Elevation}.
Figure 4a. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) for single-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 4b. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) for a dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 4c. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) for a four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
While the single-feed antenna in Figure 4 shows a big variation of the DGD when moving from zenith (that is, Elevation = 90°) to lower elevations, a substantial decrease in the DGD spread is recorded for the four-feed solution, with the dual-feed one having again intermediate results.
It is worthwhile noticing that the results obtained for the dual-feed solution are in agreement with the current MOPS for L1 antennas (RTCA DO-301), specifying a maximum value of 2.5 nansoseconds (ns) for the group delay spread at low elevations (normalized to boresight, El = 90°).
The results show how angular variation of the DGD can be related to non-uniformity along the aspect angle (Az or El) and frequency, hence suggesting to use multiple-feed solution for obtaining optimal performance.
A useful metric to quantify the uniformity of the group delay can be introduced as the Uniformity Indicator for Group Delay (UIGD):
( 2 )
with being the sum over frequency (Nf is the number of frequency steps considered) and DGDzenith,n being the value of the DGD at zenith for frequency n.
The UIGD expresses the maximum variation of the DGD over elevation and azimuth from a reference condition (the DGD at zenith) in the bandwidth of interest, extending de facto the MOPS requirements by considering the whole bandwidth behavior in the whole upper hemisphere.
The UIGD for the one-, two- and four-feed antennas is respectively 4.18, 1.03 and 0.05 ns, hence effectively mirroring the better pattern uniformity of the four-feed solution.
The UIGD is a comprehensive metric to describe the DGD uniformity, but needs accurate phase measurement over the entire bandwidth, which may not be always easily obtainable. As a matter of fact, phase can be challenging to measure: some indication of the areas most likely to deliver increased DGD can be found while considering gain patterns, qualitatively providing an easier metric to compare different antennas. In this case, the Uniformity Indicator for Gain (UIG)can be used:
(3)
The UIG expresses the maximum value over all elevation and azimuth angles of the standard deviation of the RHCP gain derivative over frequency (in the band of interest), therefore indicating the roughness of the antenna gain pattern in frequency and angle.
Such a metric does not relate totally with DGD behavior, but serves as an easier metric of pattern uniformity. The UIG for the one-, two- and four-feed antennas is respectively 68.5, 5.7 and 0.3%.
REAL-LIFE PERFORMANCE AND IMPACT ON ACCURACY
To evaluate the performance of actual antennas, three prototypes were measured in a Satimo Starlab anechoic chamber at the German Aerospace Center (DLR).
The antennas under test were:
A badly polarized COTS active antenna, having a behavior similar to that of a single-feed antenna;
An in-house developed passive antenna with two feeds;
An in-house developed passive four-feed antenna.
All antennas were properly tuned to obtain optimal gain and minimum reflection losses (input reflection coefficient <–10 dB) at L1 /E1 central frequency.
The measured RHCP pattern for the various antennas is shown in FiGURE 5. The UIGD for these antennas is 0.9, 0.7 and 0.2 ns respectively, while the UIG is 46.6, 38.5 and 9.0%.
Figure 5a. Measured 3D RHCP gain patterns at f=1575 MHz for a badly polarized COTS antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 5b. Measured 3D RHCP gain patterns at f=1575 MHz for a DLR dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 5c. Measured 3D RHCP gain patterns at f=1575 MHz for a DLR four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Differential group delay was calculated from the measured phase values and is shown in Figure 6.
Figure 6a. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) as from measurement for a badly polarized COTS antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 6b. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) as from measurement for a DLR dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 6c. Differential group delay versus elevation angle and frequency (each color represents an azimuth value) as from measurement for a DLR four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
The results are similar to those obtained from simulation and clearly show the improved flatness of the DGD for the four-feed case.
Moreover, if the measured phase data are fed into an ideal GNSS receiver, able to provide the tracking biases occurring in the pseudorange code measurement for all elevations and azimuths, antenna-effects-only (as weighted by the signal characteristics) will be visible (as in this case, neither multipath nor receiver or satellite imperfections are included in the ideal receiver). The results are shown in Figure 7.
Figure 7a. Pseudorange bias versus elevation angle (each color represents an azimuth value) at L1 band for badly polarized COTS antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 7b. Pseudorange bias versus elevation angle (each color represents an azimuth value) at L1 band for a DLR dual-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
Figure 7c. Pseudorange bias versus elevation angle (each color represents an azimuth value) at L1 band for a DLR four-feed antenna. Source: Stefano Caizzone, Mihaela-Simona Circiu, Wahid Elmarissi, Christoph Enneking, Michael Felux and Kazeem A. Yinusa, German Aerospace Center (DLR)
A substantial decrease in the antenna-induced error is evident as expected when the four-feed antenna is used.
The differences in performance among different antenna technologies shown here provide valuable insight in the choice of the antenna technology for a specific application, thanks to the better understanding of the impact of the antenna characteristics on the error at pseudorange level. Moreover, they can support the evaluation and definition of antenna requirements and connect them to the expected GNSS pseudorange error, such as during the process of MOPS definition as currently occurring for DFMC systems.
CONCLUSIONS
After investigating the effects of pattern uniformity on antenna-induced errors, group delay behavior over aspect angle and frequency has been shown comprehensively for different antenna feeding technologies for the first time. Minimal error in pseudorange measurements is obtained when the antenna has a smooth pattern, with no abrupt variations or nulls/sidelobes both in aspect angle and frequency. Different antenna feeding technologies currently in use for circularly polarized radiation have been evaluated, and the best performing one has been identified in the multiple-feed solution.
Both a comprehensive and an easier-to-measure metric for group delay uniformity have been identified, providing useful insight for fast comparison of the performance of multiple antennas in terms of GNSS accuracy.
STEFANO CAIZZONE received a Ph.D. in geoinformation from the University of Rome, Tor Vergata. He is is responsible for the development of innovative miniaturized antennas in the antenna group of the Institute of Communications and Navigation of the German Aerospace Center (DLR).
MIHAELA-SIMONA CIRCIU received a master’s degree in computer engineering from Technical University Gheorghe Asachi, Romania, and a master’s in navigation and related applications from Politecnico di Torino, Italy. She works on the development of the multi-frequency multi-constellation Ground Based Augmentation System for DLR.
WAHID ELMARISSI received a Dipl. Ing. in electrical engineering from the University of Applied Sciences, Kiel, Germany. He is responsible for measurement and manufacturing of antennas and antenna electronics at DLR.
CHRISTOPH ENNEKING received a MSc. degree in electrical engineering from the Munich University of Technology. He conducts research in GNSS signal design, estimation theory and GNSS intra- and inter-system interference at DLR.
MICHAEL FELUX is a research associate specializing in GBAS integrity issues for CAT -II/III operations and program manager for the research on GBAS navigation at DLR. He graduated in technical mathematics at Technische Universität München.
KAZEEM A. YINUSA received MSc. and Dr.-Ing. degrees in electrical engineering from the Technische Universität München. He is a researcher at DLR.
NavVis, a mobile indoor mapping, visualization and navigation company, released new mapping software that significantly improves the accuracy of simultaneous localization and mapping (SLAM) technology in indoor environments, such as long corridors, the company said.
The software update will be available for users of the NavVis M3 Trolley and will significantly improve the accuracy of the resulting maps and point clouds. NavVis’ mobile mapping system, the M3 Trolley, builds upon SLAM to increase speed and efficiency when scanning buildings.
The images below demonstrate the impact of NavVis Precision SLAM technology. The left image depicts a long corridor mapped with a conventional SLAM system where the above-mentioned drift error has occurred. The green outline shows how the map deviates from the true structure. The image on the right shows the significantly improved map accuracy obtained when mapping the same area using the M3 Trolley with the new Precision SLAM technology.
Image: NavVis
Here is a closer look:
Image: NavVis
SLAM is a technique originally developed by the robotics industry that is now increasingly being used in surveying and autonomous driving technologies. It solves a core problem that long plagued robotics engineers by enabling a device to determine its location while simultaneously mapping an unknown environment. This is done by chaining millions of measurements into a trajectory estimate.
However, even when a device captures highly accurate individual measurements, chaining them will result in an accumulation of noise and tiny measurement uncertainties. Over time, the estimated motion will start to deviate from the true motion (drift error). This can often be observed as a slight bending of long corridors that are actually straight. All available SLAM systems — regardless of whether these use LIDARs or other sensors — are inherently affected by this phenomenon.
The NavVis Precision SLAM technology significantly reduces drift error and improves the SLAM accuracy. This is particularly evident in cases where complementary techniques such as loop closures cannot be deployed, if, for example, the building’s layout does not allow for it.
Precision SLAM even improves accuracy when SLAM anchors are used to incorporate ground control points into the mapping process.
“I am very excited about our new Precision SLAM technology,” said Stefan Romberg, head of mapping and perception at NavVis. “We are always striving for the highest possible map and point-cloud accuracy and improving SLAM is a critical component to being successful. It is widely known among SLAM developers and users that complementary approaches such as loop closures or ground control points are needed to achieve a high accuracy.
“However, with the Precision SLAM technology we have developed an approach that not only nicely complements the former techniques but is especially evident when these have little effect or cannot be used.”
Fractus Antennas has launched a mobile antenna that enables coverage at 3G, 4G and 5G — the TRIO mXTEND chip antenna component.
The TRIO mXTEND has been specifically designed to provide flexibility to operate any required frequency band inside any wireless device.
It is capable of operating the main mobile communication standards, enabling worldwide coverage, as well as GNSS such as GPS, GLONASS and BeiDou (1561 MHz, 1575 MHz and 1598-1606 MHz) and the main short range wireless bands such as Bluetooth and Wi-Fi (2400-2500MHz and 4900-5875MHz) through the same antenna component.
The TRIO mXTEND is a modular, multiband and multi-port antenna component that enables top-quality worldwide coverage at any mobile communication standard. Its reconfigurable and off-the-shelf nature allows multiple architectures so the antenna component can be assembled into any mobile or IoT device.
It has been designed for providing mobile operation in three different frequency regions: 698-960 MHz, 1710-2690 MHz and 3400-3800 MHz. In addition, TRIO mXTEND is presented in an ultra slim component of 1 millimeter that enables easy placement into any device.
The Fractus Antennas team will be at Mobile World Congress in Barcelona, either at the venue or in Fractus Antennas Headquarters, which is based in the city. Those interested are invited to arrange a meeting.
SBG Systems has released the Ellipse 2 Micro series, a new product range designed to reduce the size and cost of high-performance inertial sensors for volume projects. The Ellipse 2 Micro series is available as an inertial measurement unit (IMU), or as an attitude and heading reference system (AHRS) or inertial navigation system (INS) running an extended Kalman filter.
The new Ellipse 2 Micro is available as an IMU for calibrated sensor data, or as an AHRS/INS delivering accurate orientation and navigation using an external GNSS receiver.
The Ellipse 2 Micro series provides excellent navigation data when connected to an external GNSS receiver. The INS fuses in real-time inertial and GNSS information to maintain the vehicle position in air, marine or land applications. For automotive projects, the inertial sensor comes with CAN protocol and connects to the odometer for higher performance in harsh environments, such as tunnels and urban canyons.
“With the Ellipse 2 Micro, integrators benefit from SBG Systems high expertise in motion sensing and positioning in the smallest package,” said Alexis Guinamard, CTO of SBG Systems.
The high-quality micro IMU is calibrated from -40 degrees to 85 degrees Celsius. Combining state-of-the-art MEMS-based gyroscopes, accelerometers and magnetometers, the new Ellipse 2 Micro series is fully calibrated in temperature to eliminate measurement errors such as sensor bias, gain, linearity, alignment and g-sensitivity to provide a constant behavior in all conditions.
Weighing 10 grams, the Ellipse 2 Micros provide a 0.1 degree accurate attitude and connects to external GNSS for navigation, offering a remarkable weight/performance ratio to integrators.
All Ellipse 2 Micro models are now available for order. Product and pricing information is available from SBG Systems representatives and authorized dealers.
Tallysman, a manufacturer of high-performance GNSS antennas and related products, is offering a new light-weight compact GPS L1/L2 + GLONASS G1/G2 antenna, available either as an OEM (TW1829) antenna or in a housed version (TW8829).
The antenna is designed for unmanned aerial vehicle use because of its low aerodynamic profile and very light weight. The TW1829 weighs 37 grams and is 48mm (d) x 12.2mm (h). The TW8829 weighs 52 grams and is 47.3mm (d) x 18.3mm (h).
The antennas employ Tallysman’s Accutenna technology, which has proven its ability to provide high-level rejection of multipath signals, a phase linear response and tight phase centre variations (PCV).
Additionally, the antenna has pre-filters to prevent the saturation of the front end LNA by strong near frequency and harmonic signals.
The antenna is available with a choice of connectors and custom cable lengths. Additionally, Tallysman can custom tune the TW1829 for the customers’ enclosure to ensure optimal performance.
Tersus GNSS Inc. has launched the BX306Z GNSS RTK board, which has powerful flexibility and compatibility to meet the needs of original equipment manufacturers (OEMs) and system integrators, according to the company.
As a new member of the BX-series GNSS OEM boards, BX306Z is a cost-efficient GNSS real-time kinematic (RTK) board for positioning and raw measurement output.
The board is a compact, multi-GNSS (GPS L1/L2, GLONASS G1/G2, BeiDou B1/B2) RTK module with centimeter-level accurate positioning capability.
Features
The BX306Z is able to integrate with autopilots and inertial navigation units.
Log and command is compatible with major GNSS boards.
With flexible interfaces, the pin-to-pin design is compatible with Trimble BD970.
All of these features help manufacturers reduce their application cost and lead time to market.
7-channel multi-GNSS multi-band for software-defined receiver
The NT1065/66_USB3 multi-channel GNSS RF front-end board is based on NTLab’s RF ICs: NT1065 (four channels for GPS / GLONASS / Galileo / BeiDou / IRNSS / QZSS, L1/L2/L3/L5 bands) and new NT1066 (two channels for all previously mentioned GNSS signals, plus one extra-channel for IRNSS S-band). The board supports USB3 connection, allowing users to process captured satellite signals on a PC or DSP platform. The board is accompanied by comprehensive software and manuals. Features include six channels for L1/L2/L3/L5-band signals + one channel for S-band signals simultaneous reception; up to four coherent channels; IF bandwidth up to 32 MHz; acquisition of wideband signals up to 64 MHz (such as Galileo E5) by two coherent channels; USB3 interface (up to 800 Mbit/s); ability to connect four x CRPA. NTLab offers an academic discount program for universities, colleges and institutes, allowing them to purchase this powerful research tool with significant savings.
Three new Tersus GNSS HRS kits feature high-precision BX305, BX306 and BX316 GNSS RTK boards. The kits consist of RTK receivers, GNSS antennas, RS05R radio station modems, radio station antennas, and related cables and converters. Embedded in the receivers are the Tersus RTK boards. They are compact-design, energy-efficient, centimeter-level accurate GNSS real-time kinematic (RTK) boards that bring high-precision positioning accuracy to the market. Different from the standard BX305/306/316 GNSS kits, the new HRS versions are equipped with the RS05R lightweight and robust UHF rover radio for wireless applications. It provides reliable data communication for demanding conditions that require a combination of stability, high performance and long-range operation. The kits can be used in a variety of applications, such as unmanned aerial vehicles (UAVs), surveying, mapping, precision agriculture, construction engineering and deformation monitoring.
Spoofer detection is now available on all JAVAD GNSS original equipment manufacturer (OEM) boards. When a receiver equipped with a JAVAD board detects more than one correlation peak for any PRN code, it warns the user of the presence of spoofing (false signals) and identifies the spoofed satellites. The receivers then switch to other signals and sensors that are not being spoofed to maintain accurate positioning. The user can also employ the receiver to try to identify the direction from which the spoofing signals are originating.
The ScanStation P50 combines all the features of the P40 plus a longer range scanning capability of more than 1 kilometer. The rugged, versatile laser scanner enables professionals to 3D capture at great distances with angular accuracy paired with low-range noise and survey-grade dual-axis compensation. The ScanStation P50 opens new business opportunities for reality-capture professionals, helping them to scan what was previously unreachable such as big mine pits, long bridges, dams and skyscrapers. With its range, the P50 enables users to scan any tall or wide infrastructure or dangerous sites from a remote and safe position. This newest member of the P-Series provides the highest quality 3D data and high-dynamic range (HDR) imaging at an extremely fast scan rate of up to 1 million points per second and ranges of more than 1 kilometer.
Azuga FleetMobile: Standalone Smartphone Edition (SSE) is a smartphone-based solution for driver behavior monitoring, mobile timecard management and GPS tracking. Azuga FleetMobile SSE leverages data analysis components of the original Azuga FleetMobile application, including driver behavior monitoring, location-based timestamps for timecards, gamification and driver rewards, without requiring separate hardware installation via a vehicle’s OBD port. Azuga’s GPS fleet-tracking offerings feature a driver rewards program to help fleets reduce accidents by up to 70 percent. The standalone application, which works on both Android and iOS smartphones, integrates gamification and real-time data to encourage self-coaching and healthy competition. Azuga’s data science team can then leverage information about driving behaviors and combine them with route patterns, fleets’ vehicle health information and environmental factors to identify opportunities for performance improvements in fleet operations.
The RIFA series of full-featured GPS trackers have built-in gyro and G-sensors, and supports OBDII and J1939 protocols. In addition to 4G/3G communication, it provides options to use low-power wide-area networks (LPWAN) such as NB-IOT or LoRa, which can reduce communication costs significantly. The unique CAN-to-ADR (automotive dead reckoning) function provides accurate positioning in situations of weak GPS signals, such as driving in tunnels, indoor parking facilities, urban canyons or when GPS signal obstruction hinders positioning, without additional cabling for wheel speed input.
The ThermalCapture IRnet provides an Ethernet interface for live data streaming to new and existing FLIR Tau 2 drone cores and FLIR Vue Pro/R cores. The market has increased its demand for connectivity by Ethernet, with professional drone manufacturers choosing Ethernet for communication on board UAVs. The ThermalCapture IRnet allows for real-time access via Ethernet while recording radiometric data to microSD, bringing real-time access in drone flight operations to thermal imaging data. It stores the full 14-bit radiometric thermal data on a microSD card. Real-time access remains available while radiometric data are being recorded; operators can also control the camera and settings via Ethernet. Using Ethernet also offers data privacy.
The Think 3D Stormbee multicopter integrated with Trimble’s AP15 provides efficiency, accuracy and performance for lidar surveys from unmanned vehicles. The Stormbee is a directly georeferenced UAV lidar solution for 3D industrial mapping applications, designed to collect survey-grade spatial data more cost effectively and efficiently than static lidar. Stormbee’s 3D mapping technologies include Faro’s Focus 130 laser scanner, Trimble’s AP15 high-performance GNSS/inertial receiver, Applanix’s POSPac UAV GNSS/inertial post-processing software and Stormbee Beeflex software for lidar point-cloud generation. By using the high-performance Trimble AP15 with two antennas and the Applanix post-processing software (POSPac MMS) for georeferencing the lidar data, Stormbee provides an accurate real-time and post-mission solution for all motion variables.
u‑blox is offering the automotive-grade MAX‑M8Q‑01A GNSS module, which measures 9.7 x 10.1 x 2.5 millimeters and has an operating temperature range from –40 degrees Celsius to 105 degrees Celsius.
The MAX‑M8Q is the company’s third automotive-grade GNSS module to date, alongside the NEO‑M8Q‑01A and NEO‑M8L‑03A modules.
MAX‑M8Q‑01A is designed to meet the stringent requirements of the automotive market, providing superior positioning accuracy even in challenging environments such as urban canyons. Its extended temperature range ensures reliable performance even in harsh environments, e.g. when mounted in a car‑roof antenna.
Produced in adherence to the u‑blox 0 ppm program, which aims to bring down product failures rates to zero and consistently achieve high production quality, the module is delivered with the automotive industry’s standard PPAP documentation to ensure compliance with customer requirements.
The module offers product developers a reduction of design and qualification time and effort, shortening time‑to‑market and considerably reducing risks for new product development.
“We developed this automotive grade GNSS module in the small MAX form factor in response to customer requests for a GNSS receiver that operates reliably in an extended temperature range,” said Franck Berny, senior principal, automotive market development, u-blox. “We are confident that the module’s high quality, robust and secure performance, and small form factor will appeal to the automotive industry at large.”
If a passenger-carrying drone could cost about the same as a regular passenger car, like those used by taxi and Uber drivers, then the economics might work. So it’s interesting that an outfit in the United Kingdom — Autonomous Flight — is talking about building passenger-carrying drones for around $25,000.
Autonomous Flight says has a prototype up and running, testing the concept in Southern England; testing with passengers is expected to get underway this year. The YS6 is battery-powered with multiple redundant systems for safety and is designed to fly at 70 mph, with a range of 80 miles at 1,500 ft.
This happens to meet a design goal of covering a distance from Heathrow Airport to Charing Cross train station in 12 minutes, a journey that would normally take around an hour by car in London traffic. There are similar “hops” that could save a massive amount of time in almost every city in the world.
But don’t hold your breath. It could take more than five years to get regulatory approval for the vehicle and for the initial routes over cities — never mind the time needed to get this particular concept into large-scale production to achieve the target price. But it’s nevertheless a good sign with good prospects for the future.
Drone Recovery System
While the U.S. Federal Aviation Administration (FAA) considers the regulations for drone flights over people, in the meantime several applications have been developed for people-overflight with drones equipped with parachutes.
Presumably, a drone would be safer if lowered by parachute in the event of equipment failure, but apparently such applications that rely on parachutes for risk mitigation have all been turned down by FAA. University of Alabama and Virginia Tech research has indicated a 70 percent chance of significant injury or death when a drone the size of an 8.85-pound DJI Inspire 2 fails and falls onto people.
Indemnis in Anchorage, Alaska, has been working with the FAA and other interested stakeholders to draft the regulatory standard for flight over people and has now gone on to develop its Nexus ballistic drone recovery system, which it plans to have on the market by next summer.
With a retail price of between $1,700 and $2,500, the system is expected to satisfy these coming FAA regulations for UAS flight over people and in urban areas for Part 107 commercial operations, but would seem to be quite expensive for smaller recreational drones.
The system is scalable for drones from eight pounds to “several thousand” pounds. The Nexus system is designed to automatically deploy within 30 milliseconds of detecting a failure on the drone or of entering unrecoverable flight, and the system is capable of determining normal flight or a failure to within six feet of vertical movement.
According to Indemnis, more than 10,000 requests for flight over people have been received by the FAA in the last 14 months, but all those that rely on parachutes for risk mitigation have been refused. This is apparently because conventional parachute systems have a tendency to become tangled with the aircraft or manual deployment is required. It is also said that current quadcopter drone safety systems — which cut power to an engine to prevent tumbling and which slow descent by adding power to the remaining engines — are inadequate for flying over people.
The Nexus system automatically detects failure, cuts engine power, and deploys an aircraft parachute within 30 milliseconds, slowing vertical speed to around 7 mph. This should be slow enough to allow the operator to catch up with the vehicle before it hits the ground. However, reducing vertical speed is only half the solution, as a vehicle under parachute will still travel horizontally due to wind velocity. So Indemnis is testing their parachute system with an airbag on a 33.29-pound DJI M600 drone. The airbag turns the drone “into a giant pillow” once the chute deploys.
The expected FAA standard is anticipated to require 45 tests in two failure modes — critical motor failure and full motor failure — at full flight speed, hover, and in automatic and manual deployment scenarios. Tests with a DJI Inspire 2 cutting one motor, two motors or four motors have pitched the drone violently just before it enters a slow roll — at 60 mph, it will roll quickly and violently.
This drone safety and recovery system is expected to be on the market within the next few years, following release of the projected FAA standards.
GoPro Karma hits the dust
In what would seem to be an unusual turn of events in a rapidly expanding market, GoPro has decided to exit the UAS vehicle business. GoPro cameras are still a favorite on a wide range of UAVs, but the company has chosen to get out of the business of making end-item unmanned vehicles, despite reaching second place in market share in 2017 for its price range.
At the Consumer Electronics Show (CES) Jan. 9-12 in Las Vegas, GoPro explained that its decision was based on inadequate returns versus the investment required to support their single-product UAS business.
However, Karma’s demise was apparently brought on not only by an expensive initial product recall, but also by the apparent additional financial pressure of poor Hero5 camera sales.
Nevertheless, GoPro still feels that the “action-camera” market has the legs to sustain growth, so it’s likely UAV manufacturers will not have to go looking for another reliable video camera source any time soon.
Joint venture for solar HALE UAS
The solar-powered Helios in flight.
In late 1990s/early 2000s, NASA contracted with AeroVironment to develop a high-altitude solar-powered UAS for NASA’s Environmental Research Aircraft and Sensor Technology, or ERAST, program.
In August 2001, the Helios prototype reached a world-record altitude of 96,863 ft., and in 2002 the Pathfinder Plus prototype provided from 65,000 feet high-definition television (HDTV) signals; third-generation (3G) mobile voice, video and data; and high-speed internet.
AeroVironment has now formed a joint venture with Japanese SoftBank Corporation to develop a solar-powered high-altitude long-endurance (HALE) UAS for commercial operations that may include applications such as high-altitude pseudo-satellites.
The joint venture — known as HAPSMobile — is a Japanese corporation in which AeroVironment holds minority ownership but is still able to directly exploit commercial and military opportunities outside Japan.
Summary
It’s encouraging to see another airborne taxi initiative joining the folks who were demonstrating prototypes in Dubai back last September. If the market is there, more entrants should help make this option a reality.
It’s also good news that a company already has a drone recovery system in the works that could reduce the potential for injury in the event one falls out of the sky. This might start to reverse adverse public opinion about drones and help the FAA move forward with regulations allowing wider usage.
Meanwhile, it’s sad but true that new industries inevitably see some entrants pull back and even leave in the early stages. It’s fortunate that popular drone camera supplier GoPro still has the ability to retrench and fall back on its existing business.
Finally, the promise of high-altitude solar-powered drones would seem to be still alive. If it could be possible to hang TV and other comms systems on these high-altitude loitering vehicles, there might be a much less expensive way of getting transmitters into very high altitude orbits without the cost of a space launch. Then many areas around the world could benefit from low-cost signal distribution that might not otherwise work commercially.
