Patent Application
20180175495
These teachings relate generally to methods and systems for wet radome attenuation mitigation in phased-array antennae applications and the networked use of such applications.
The vast majority of weather radar systems are covered by a radome. This is essential to protect expensive radar components from the impact of severe weather such as hail. It also reduces the wear of pedestal subsystem by isolating it from the strong winds. The effect of an attenuation induced by a film water, rivulets and droplets present on a radome scales up with frequency and is especially disadvantageous in communication systems operating in 20 GHz band. Chang (1985) has shown that the two-way attenuation can be as high as 6 dB (or 75%), assuming that the radome surface is hydrophobic. However, the hydrophobicity property of radome usually degrades over time and an increase in two-way attenuation up to 10 dB (or 90%) can be expected (Kurri and Huuskonen, 2008). There are currently two options to reduce the bias introduced by a wet radome. First, a straightforward method to compensate on a wet radome induced attenuation is by an increase in the transmitted power. However, the cost of a peak transmitted power increases with frequency, and hence this solution is expensive. Alternatively, one can periodically polish the surface of a radome and reapply hydrophobic coating. Salazar et al (2014) reports that this procedure should be repeated every 9 months, which is very time consuming. Additionally, this option is not always feasible due to the remote locations of radio communication systems (towers, mountains).
In the weather radar operation this effect is negligible at lower frequencies (US NEXRAD system), but becomes more significant at C-band and X-band. Trabal et al (2008) compared a reflectivity obtained by CASA X-band radars with US weather surveillance radar operating at S-band and reported radome attenuation as high as 7.5 dB. In practical situation when rain accumulates on the radome an unknown attenuation is added to an entire rain profile and in consequence a rain rate (and thus potential for Hooding) is considerably underestimated. Operation without radome is not recommended and an increase in the transmitted power is not possible due to the fact that weather radars operate usually in the amplifier's saturation region. The current attempts toward real-time attenuation correction (Gorgucci et al 2013) can be only applied to the weather data with signal-to-noise ratio larger than OdB. Hence, in weather radar systems, radome attenuation always results in an unrecoverable loss in radar range coverage. Finally, although the effect of an accumulating snow or freezing rain (or rivulets) on a radome surface is not well studied, it shouldn't be overlooked. When the temperature of water goes down the attenuation effect will increase even further.
There is a need for a radar enclosure that mitigates the attenuation due to rain and snow in present radar enclosures. There is also a need to be able to increase the range of radar coverage and data collection potential to ultimately increase the accuracy of the readings.
The radar enclosure and the methods of these teachings mitigate the attenuation due to rain and snow. Further, the networking of the radar with such enclosures increases the radar coverage by adding to the possible collection of locations and thus potentially increasing the data to be analyzed—ultimately increasing the accuracy of the readings.
In one or more instances, the radar enclosure of these teachings includes two side wall components, a top aerodynamically streamlined shape component, the two side wall components extending from the base surface to the a top aerodynamically streamlined shape component forming an enclosure cavity, and an antenna supporting component disposed in the enclosure cavity and configured to support a phased array antenna, the phased array antenna being disposed at an angle with respect to a normal to the base surface. In one instance, the angle with respect to the base surface is between 45° and about 90°. In another instance the radar enclosure of these teachings also includes a flow redirecting component disposed in the enclosure cavity and configured to redirect flow out of the enclosure cavity and away from the antenna supporting component.
Individual radar operational elements capable of detection, due to power limitations or by design, for relatively short distances, such as, for example, a few hundred meters with the level of power used for, for instance, long-range automotive type radars, could be networked together to provide continuous, overlapping coverage of a line of view or area of interest. If the radar operational elements are mobile and equipped with communications and location detection (e.g. GPS), they can be programmed to self-assemble into an array.
In one or more instances, the method of these teachings includes installing a phased array antenna in a radar enclosure, where the radar enclosure includes two side wall components, a top aerodynamically streamlined shape component, the two side wall components extending from the base surface to the a top aerodynamically streamlined shape component forming an enclosure cavity, and an antenna supporting component disposed in the enclosure cavity and configured to support a phased array antenna, the phased array antenna being disposed at an angle with respect to a normal to the base surface.
By connecting the radar operational elements—with the inventive elements (as summarized above), the resulting radar operational element system can provide coordinated detection in real or near real time. In one embodiment, the inventive system can exploit the features of existing high-resolution wide band radar technology (e.g. automotive radar operational elements) to create, for example, an array of detectors that are less tasked in their individual operational element operations and thus, as a system, more efficient and effective in collecting data. This array can be manually or automatically assembled. Because each radar operational element can be small and self-contained, each can be mounted on a roof of a vehicle, or secured of securing in a fixed geographical location, such as, for example, on a building roof, on a pole, or anywhere from where the radar operational element can have an unobstructed view (e.g., when collecting overhead data, a “view of the sky”). One of ordinary skill in the art would also recognize that the vehicle to which the radar operational element is mounted could transport the element over water or through the air. With this flexibility in location, users can situate a radar operational element for the most desired data collection. In a preferred embodiment of the present invention, the radar operational element has communications, processing and navigation/location determination capabilities (or it can be pre-programmed with a location when it is installed). It can be powered by, for instance, (A) vehicles upon which it is mounted, (B) batteries, (C) solar panels, (D) fuel cells, (E) forms of wind-generated power, or (F) wiring it into the local power grid.
The invention as a method would comprise the step of transmitting signals between radar operational element(s) and a main control location. This communication could be used, in part, to facilitate the transmitting of signals between transmission enabled objects and the radar operational element(s). With the communication between the radar operational element(s) and the transmission enabled objects established, the transmission enabled objects can be monitored with more precision, using this embodiment of the inventive method. The signal between the radar operational element(s) and the main control distal location may be transmitted via over-the-air technology or via wires, fiber-optic cable or similar and the monitoring of the transmission enabled objects may be made while the radar operational element(s) are mounted on movable objects.
A number of other embodiments are disclosed hereinbelow.
For a better understanding of the present teachings, together with other and further needs thereof, reference is made to the accompanying drawings and detailed description.
The following detailed description presents the currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context dearly dictates otherwise.
Except where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.”
“Aerodynamically streamlined component” as used herein, refers to a component design or configuration in which the difference in fluid pressure against a leading edge of the component and the fluid pressure against the trailing edge of the component is reduced, resulting in reduced pressure drag.
In one or more instances, the radar enclosure of these teachings includes two-side wall components, a top aerodynamically streamlined shape component, the two side wall components extending from the base surface to the a top aerodynamically streamlined shape component forming an enclosure cavity, and an antenna supporting component disposed in the enclosure cavity and configured to support a phased array antenna, the phased array antenna being disposed at an angle with respect to a normal to the base surface. In one instance, the angle with respect to the base surface is between 45° and about 90°. In another instance the radar enclosure of these teachings also includes a flow-redirecting component disposed in the enclosure cavity and configured to redirect flow out of the enclosure cavity and away from the antenna-supporting component.
In one or more instances, the method of these teachings includes installing a phased array antenna in a radar enclosure, where the radar enclosure includes two side wall components, a top aerodynamically streamlined shape component, the two side wall components extending from the base surface to the a top aerodynamically streamlined shape component forming an enclosure cavity, and an antenna supporting component disposed in the enclosure cavity and configured to support a phased array antenna, the phased array antenna being disposed at an angle with respect to a normal to the base surface.
The present teachings are explained herein below by an application to the weather radar.
These three models were simulated in a wind tunnel using Autodesk Design Flow to evaluate their aerodynamic properties under strong wind conditions (31 m/s). The simulations revealed that winds up to 51 m/s in the vicinity of the flat panel can be expected, while in case of standard shapes they are limited to 38 m/s. Moreover, the maximum wind pressure on the surface of antenna is almost doubled (1281 Pa) when compared to sphere (655 Pa). The wind streams in excess of 40 m/s are going upward over the radar enclosure. In a consequence the moisture present on a radome surface is ‘pushed inside and upward’, rather than down and away from it.
In an effort to address the limitations of current radome solutions, a radar configuration of these teachings is shown in
In one instance, a flow redirecting component, such as, but not limited to a blower or fan, is disposed in the radar enclosure cavity and is configured to redirect the flow out of the cavity and away from the phased array antenna. Such a configuration is shown in
This structure was simulated in a wind tunnel under the same strong wind conditions (31 m/s) as the previous three models. The shape of the invented radar enclosure exhibits lower drag coefficient than radome based on a sphere. The maximum wind pressure on an antenna surface (576 Pa) is reduced by a factor of 2:1 compared with a basic flat panel. The wind speed in the vicinity of an antenna panel is less than 6 m/s and the wind direction is downward (see
The phased-array antenna enclosure of these teachings presented in
A prediction tool can be used to map out the best locations for one or more the radar operational elements. This prediction model uses any local geographic information to determine the optimal number and location of the radar operational elements to guarantee best coverage of the area, perimeter or line of interest to the operator (the geographic data can be further augmented by performing a 3D survey of the area). Once the location(s) are determined, the operational element(s) are deployed to the assigned area(s). Each radar operational element can be self-surveyed into position or be mounted and externally surveyed. When installation is complete, the system can be already active.
To sum up with respect to the individual radar operational elements, it is believed that the phased-array antenna enclosure of these teachings has a potential to significantly reduce the amount of water present on a radome surface during heavy rain or snow events. This will lead to more reliable operation and cost effective design of a high frequency radio systems based on phased-array technology.
The following are incorporated by reference here in in their entirety and for all purposes: Chang, K.-C., 1985; System performance in rain in a radome-enclosed environment 1985 IEEE Military Communications Conference: MILCOM '85, Vol. 1, IEEE, 293-299, Kurri, M, and A, Huuskonen, 2008: Measurements of the transmission loss of a radome at different rain intensities. J. Atmos. Oceanic Technol, 25, 1590-1599, Gorgucii, E, R. Bechini, L. Baldini, R. Cremonini, and V. Chandrasekar, 2013: The influence of antenna radome on weather radar calibration and its real-time assessment J. Atmos. Oceanic Technol, 30, 676-689, Salazar-Cerro J., V, Chandrasekar, Jorge M. Trabal, Paul Siquera, Rafael Medina, Eric Knapp, and David J. McLaughlin, 2014: A Drop Size Distribution (DSD)-Based Model for Evaluating the Performance of \Vet Radomes for Dual-Polarized Radars. J, Atmos. Oceanic Technol, 31, 240972430, Trabal, J, M., I. Zawadski, and D. McLaughlin, 2008: A method to correct for wet radome attenuation in CASA radars by the use of a contiguous WSR-88D radar. Proc. Fifth European Conf on Radar in Meteorology and Hydrology, Helsinki, Finland, ERAD, 0287.
As shown in
The inventive system may also include one or more operator control units (OCUs), which could be used to display the radar coverage over a map of the local area. The OCUs could also be part of a main control computer through which the system user could transmit and receive information and data in exchanges with the radar operational element(s). These possible transmissions may be conducted through various means that are known to those of ordinary skill in the art (e.g., through the use of radio signal technology, other wireless equipment, wired components and more/alternatives). Where multiple radar operational elements are electronically connected, via the main control computer, to each other the perceptive strength of a resulting array of radar operational elements is more powerful than each individual radar operational element alone.
The OCUs also may display the health of each individual radar operational element, and, in configurations in which the focus of the radar operational elements is skyward, highlight any airborne objects, and provide trajectory information (e.g. path over time). The OCUs can be connected to both the detection system as well as the Internet, thereby allowing the information to be shared as necessary. The OCU can check actual vs. desired coverage and provide corrections as necessary (or update the map to reflect actual radar locations). As an additional option, if the inventive system is connected to a source of information about the surrounding area, in particular information about authorized objects or other aircraft or the location of objects are, for example, intended to be moved as desired by the system user or not at all, the OCU will display that information by denoting authorized objects on the display as they are monitored and/or tracked.
In reference to
In one preferred embodiment of the present invention, radar operational elements 800, when deployed at a distance from the points of origin of object 801, are capable of communicating with the human operator/user at the points of origin or at different locations, or, if the operation is more automated, with the programmed equipment at such points of origin or different location. Main control center at remote location 802 may comprise software that includes operational objectives and a user interface and could be run on any computer that has networking and/or satellite communications access. The inventive radar operational elements 800 have the advantages of (A) reach—the multiplicity of deployments of radar operational elements 800 can cover larger areas as desired, (B) timing—the activation of radar operational elements 800 at differing times, and (C) mobility—the smaller sizes of radar operational elements 800 facilitating their deployment almost anywhere.
In particular,
In a further embodiment, remote location 802 could be enable to detect and/or track object 801. In
The human operator/user could program radar operational element 800 via the user interface. He/she could program missions, monitor transmission enabled objects in communication with radar operational elements 800, set global parameters, choose specific targets, and check the health of radar operational elements 800 or any element thereof. Such human operators/users could also, for example, select specific radar operational elements 800 locations or transmission enabled objects and monitor them closely. In addition to high-level mission parameters, the human operators/users could select specific transmission enabled objects 801 or radar operational elements 800 for direct access to data where radar operational elements 800 require human intervention (e.g. the human is required to select or approve a target).
The inventive system includes a means for transmitting information between two or more radar operational elements 800. In a further enhanced version of the inventive system transmission is exchanged between one or more radar operational elements 800 and transmission enabled objects 801. In addition to the transmission of information between radar operational elements 800 and transmission enabled objects 801, there is also, in another embodiment of the inventive system, a means for transmitting information between the radar operational elements 800 and a main control center at remote location 802, which may be a notable distance from the radar operational elements 800.
One of ordinary skill in the art would realize that the present invention could also be used to detect and track objects that are not air bound. For examples, the present invention could be used in roadside tracking activities. As part of such a deployment, one or more radar operational elements could be set up along roads or highways such that the coverage of the radar operational elements includes, for example, the area along the sides of the road or highway, the surface of such road or highway, or a combination of areas and surfaces. When an object approaches the area covered by the radar operational element, such as a deer, coyote, moose, or other moving or movable object, the system of the present invention could, for example, detect and track the approach, log the time and location of the engagement, and then transmit information about the situation to a detecting device or system (e.g., a receiver of an oncoming vehicle or a stationary monitoring system). The receiver in an oncoming vehicle could be part of or connected with, for example, (A) a mobile phone application that would, in essence, be managed by someone in the approaching vehicle or (B) the vehicle itself, if properly equipped with the necessary technology. Additional and more specific users of the present invention deployed roadside could be emergency responders or autonomous operated vehicles. With the detection and tracking of the circumstances of the area covered by the present invention system, the system can thus, for example, warn oncoming vehicles (with or without drivers) about the possibility of an animal entering the road or being on the road before such vehicles (or their drivers) might otherwise detect the animal, thereby improving safety. Further, the same system, or a derivative of it, could be used to inform emergency responders of vehicles that are stationary on the side of the road or highway—an indication that assistance may be needed.
Another area in which the present invention could be useful in connection with objects that are not air bound is on or near railroad tracks. With such an embodiment of the present invention, the radar operational elements could be, for example, set up along railroads and/or in the vicinity of railroad crossings to detect obstacles on or crossing the tracks. The system could then warn oncoming trains and/or train traffic controllers of objects on the tracks that might be hazards. In the reverse scenario, the same radar operational elements could monitor the arrival time and speed of passing trains and report such information to the train system controllers, thereby alerting the controllers with accurate information about train speeds and locations. Such detection could be made with respect to trains traveling too fast/slow or in unexpected locations.
When the present invention is deployed in a system located near or in an airport or other secure facility, the system could be configured to track airborne objects, objects on the ground, or combinations of the foregoing. The same system, or a derivative of it, could be positioned to monitor fences and property lines. In that way, the system could detect and report any attempt to access the property, such as airfields, equipment storage yards, military installations, etc.
Using the present invention in a smaller or more discrete environment, the system could be used to track objects such as footballs (as suggested above), golf balls, tennis balls, race cars, etc. Such an embodiment could supply tracking data to other systems or devices, such as, for example, tracking cameras (that could follow the ball/car). It could work in conjunction with or incorporate technology to highlight the target object for display on screens and monitors.
Still another embodiment of the invention could be used in water environments. In this case, the present inventive system could be installed along waterfronts, harbors, rivers or other bodies of water to monitor, for example, shipping traffic. The radar operational elements could be, in specific instances, placed on buoys/fixed installations at sea to monitor the local area for unauthorized ship traffic (e.g. illegal goods/people smuggling).
With regards to the inventive process, the present invention is a method of communicating with one or more transmission enabled objects. This process includes the step of transmitting a signal between a remote location and a distal location, such as, for example, a main control center. The process also includes transmitting a signal between such radar operational element's location and transmission enabled objects. The foregoing may enable the positioning of such transmission enabled objects—if and to the extent their position can be controlled remotely—in close proximity with the radar operational element's location.
The foregoing descriptions of the present invention have been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner of ordinary skilled in the art. Particularly, it would be evident that while the examples described herein illustrate how the inventive apparatus may look and how the inventive process may be performed. Further, other elements/steps may be used for and provide benefits to the present invention. The depictions of the present invention as shown in the exhibits are provided for purposes of illustration.
Although these teachings have been described with respect to various embodiments, it should be realized these teachings is also capable of a wide variety of further and other embodiments within the spirit and scope of these teachings.
The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others of ordinary skill in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15172082 | US | |
| Child | 15382644 | US |
