Where is the nrao headquarter located

These absorbers, however, add extra noise to the system and decrease effectiveness. The new design elegantly solves this problem, making it suitable for systems in which low-noise and wide bandwidth requirements are a priority, such as spread spectrum radio communications. This allows one antenna to replace many in practical use, thereby reducing costs. The wide-bandwidth applications of this technology also include radio astronomy, biomedical imaging, spectrum surveillance, and satellite communications, among others.

The CDL supports the evolution of NRAO's existing facilities and provides the technology and expertise needed to build the next generation of radio astronomy instruments.

Most-advanced radar sensors use antenna arrays and wideband waveforms that are mostly processed in the digital domain. A key specification of the proposed IC is that it can be replicated as many times as needed to satisfy the requirements of any application.

The proposed IC concept intends to exploit scale economies to decrease the costs of designing, developing and procuring advanced radar imaging processors. Most autonomous products require sensors to become situationally aware. Our concept consists of a mixed-signal IC that develops a completely new breed of analog-to-digital converters. This ADC converts the inherent bandpass nature of all radio signals navigation, surveillance and communications into an asset, by digitizing their amplitude and phase directly from the antenna, removing the need for any down-conversion, and operating at a sampling frequency equal to the signal bandwidth.

The envisioned ADC can be used in any receiver with a bandpass sensor. Nonetheless, we are targeting only radio receivers at this moment. Our initial objective for this program is to develop a wideband ADC partially covering the SHF band which spans from 3 to 30 GHz , on a best effort basis.

Similarly, the targeted sampling frequencies are about a few gigahertz. In modern optoelectronic systems, there is often a strict requirement on the variability of the system phase or delay.

This occurs on high-speed fiber optic links analog or digital , in radio interferometry, and in phased arrays. When the system incorporates a moving element, such as a steerable antenna, then the motion of the interface itself can make the system phase requirement difficult to meet. Motion can cause physical path length changes, temperature changes, and polarization changes in fiber.

The Polarization Preserving Fiber Optic Rotary Joint PPFORJ uses a patented technique to suppress all of these effects by using a single fixed length of fiber across the interface; controlling of polarization fluctuations in the fiber across the interface; smooth control of the fiber motion; and compact and efficient mechanical design.

When radio antennas or telescopes feed RFoF signals into an optical fiber, the PPFORJ keeps the state of polarization change to a minimum as the structure moves through azimuth and elevation. The innovation prevents the corruption of data where polarization changes can deteriorate the quality of the data. Based on a patented algorithm for reliable de-serialization of unformatted data streams, this sampler and decoder chipset enables high-throughput data transport with the minimum possible digital overhead and power dissipation at the source.

This complete end-to-end data collection and transport solution comprises two parts: An ultra-low-power, high-speed Serial-output Analog-to-Digital Converter SADC at the front-end, and a data re-alignment and decoding processor at the back-end.

Together, these parts create a fully-functional data link capable of streaming raw samples at up to 5 Giga-samples per second from a front-end analog sensor. To work, the input signal needs only to meet certain minimum statistical requirements that are typical of almost any naturally-occurring or noise-laden analog waveform.

The front-end SADC has been optimized to achieve high data-rates with the minimum possible pin-count, power dissipation, and digital emissions which could otherwise interfere with sensitive front-end analog electronics. Each input channel is digitized and delivered to CML-compatible outputs capable of driving industry-standard small-form-factor pluggable fiber-optic transceivers e. Alternatively, both channels may be interleaved onto a single CML output for transmission of both data streams on a single lane at half the rate.

The aligner-decoder at the back-end of the link automatically detects the most-significant bits MSBs in the data stream, and identifies the samples coming from the two input channels if they were interleaved at the front-end , presenting simultaneous samples at the output in parallel form as if the ADC was connected locally, making the serial-link and the associated physical separation effectively transparent to the back-end processor.

The NRAO has developed a method of treating reflective surfaces to reduce undesired reflections causing standing waves leading to signal drop-outs and antenna side lobes. The surface is constructed of small cells such that the relative phase of reflections from individual cells is randomized so that the reflections do not sum constructively or destructively.

Reduction of undesired reflections is typically done by re-orienting or covering the reflecting surfaces with electro-magnetic absorber, but often the surfaces are integral to support structure where it can be expensive to adapt from a simpler design, or exposed to weather where it can be problematic to weather-proof a material not typically exposed to the elements while preserving its absorption capability. In situations where desired signals are weak, emissions from ambient temperature absorber can increase the noise figure of a receiving system rendering it less sensitive than optimum.

The new synthesizer design originally designed for radio telescopes is used for local oscillators LO with increased tuning resolution and smaller synthesizer steps sizes that will provide greater flexibility and increased capability of existing hardware.

Previous synthesizer designs relied on comb generators that provided a picket fence of frequencies with fixed spacing between pickets. The flexibility of this synthesizer is obtained through the application of variable frequency comb lines where the difference between pickets is allowed to vary in order to provide tuning coverage over the full frequency range. The evolution of synthesizers for radio astronomy has been to smaller and smaller synthesizer step sizes.

By comparison, this new type of synthesizer can easily provide step sizes of 10 kHz. Additionally, these new synthesizers can provide step sizes of one hertz or less with only a small increase in complexity. Security Lab No. Charlottesville , VA Map it. Want more information? Contact a representative below. Laboratory Representative Jeff Pixton. Main Observatory. Tech Transfer Website:. Displaying 1 - 9 of 9. Description: Broadband, single-polarization horn antennas are of significant interest in a number of test and measurement applications, and many successful designs based on double-ridged geometry have been demonstrated in the cm-wave frequency band.

M A Morgan. Description: What conventional RF Filters Provide Conventional reflective filters do not dissipate spurious signals or added noise. Background High-frequency radio system engineers have numerous options for filtering requirements including topologies, synthesis equations and proven methods of implementation.

This presumption leads engineers to use filters with the following three properties: that minimize the passband insertion loss, show the sharpest possible transition between passband and stopband, and, reflect back to the source any out-of-band power rejections. US 9,, Mar 20, Sub Title: Radio Antenna Feed.

Jun 09, Description: Most-advanced radar sensors use antenna arrays and wideband waveforms that are mostly processed in the digital domain. Patent Abstract The proposed IC concept intends to exploit scale economies to decrease the costs of designing, developing and procuring advanced radar imaging processors. Patent Pending. Omar Ojeda, Stephen Wunduke. Jan 18, Description: Most autonomous products require sensors to become situationally aware.

Omar Ojeda. Dec 18, Description: In modern optoelectronic systems, there is often a strict requirement on the variability of the system phase or delay. US Patent. Description: Based on a patented algorithm for reliable de-serialization of unformatted data streams, this sampler and decoder chipset enables high-throughput data transport with the minimum possible digital overhead and power dissipation at the source.

Sub Title: Chipset to move analog data without formatting from imaging cameras, sensor arrays, radars and instrument clusters. IC, ADC. Apr 01, Description: The NRAO has developed a method of treating reflective surfaces to reduce undesired reflections causing standing waves leading to signal drop-outs and antenna side lobes. G K Watts. Description: The new synthesizer design originally designed for radio telescopes is used for local oscillators LO with increased tuning resolution and smaller synthesizer steps sizes that will provide greater flexibility and increased capability of existing hardware.

Displaying 1 - 8 of 8. Originally, its headquarters were at Green Bank. Locations: Charlottesville, Virginia: Located on the site of the University of Virginia, it is the workplace of almost scientists, including J.

Richard Fisher and Jeffrey Mangum. Green Bank, West Virginia: At this facility, the chief instrument was afeet partially steerable radio telescope, which was completed in but which completely collapsed in It is situated on the campus of the New Mexico Tech. Tucson, Arizona: Its offices are situated on the campus of the University of Arizona. The meter telescope is now managed by the Arizona Radio Observatory.

National Radio Astronomy Observatory.