Performance trade-offs and upgrade of NASA D3R weather radar

Kumar, Mohit; Joshil, Shashank S.; Chandrasekar, V.; Beauchamp, Robert M.; Vega, Manuel A.; Zebley, John W.

doi:10.1109/igarss.2017.8128188

Cited by 15 publications

(12 citation statements)

References 6 publications

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“…The D3R was configured to measure 150m range gates out to a maximum range of 39.75 km, combining a short pulse for ranges < 3.3km with a medium pulse for the remaining range gates. This gives a Ku-band sensitivity ranging approximately from -30 to -5 dBZ over the short pulse, and from -15 to 5 dBZ over the long pulse (Kumar et al, 2017). The primary scan schedule during snow events conducted a PPI scan at 5 • elevation follow by RHI scans at 51 • , 231 • , and 330 • azimuths, with each set of scans taking 5 minutes.…”

Section: D3rmentioning

confidence: 99%

Snow Microphysical Retrieval from the NASA D3R Radar During ICE-POP 2018

Munchak

Schrom

Helms

et al. 2021

Preprint

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Abstract. A method is developed to use both polarimetric and dual-frequency radar measurements to retrieve microphysical properties of falling snow. It is applied to the Ku- and Ka-band measurements of the NASA Dual-polarization, Dual-frequency Doppler Radar (D3R) obtained during the International Collaborative Experiment for PyeongChang Olympic and Paralympics (ICE-POP 2018) field campaign, and incorporates the Atmospheric Radiative Transfer Simulator (ARTS) microwave single scattering property database for oriented particles. The retrieval uses optimal estimation to solve for several parameters that describe the particle size distribution (PSD), relative contribution of pristine, aggregate, and rimed ice species, and the orientation distribution along an entire radial simultaneously. Examination of Jacobian matrices and averaging kernels show that the dual wavelength ratio (DWR) measurements provide information regarding the characteristic particle size, and to a lesser extent, the rime fraction and shape parameter of the size distribution, whereas the polarimetric measurements provide information regarding the mass fraction of pristine particles and their characteristic size and orientation distribution. Thus, by combining the dual-frequency and polarimetric measurements, some ambiguities can be resolved that should allow a better determination of the PSD and bulk microphysical properties (e.g., snowfall rate) than can be retrieved from single-frequency polarimetric measurements or dual-frequency, single-polarization measurements. The D3R ICE-POP retrievals were validated using Precipitation Imaging Package (PIP) and Pluvio weighing gauge measurements taken nearby at the May Hills ground site. The PIP measures the snow PSD directly, and its measurements can be used to derived the snowfall rate (volumetric and water equivalent), mean volume-weighted particle size, and effective density, as well as particle aspect ratio and orientation. Four retrieval experiments were performed to evaluate the utility of different measurement combinations: Ku-only, DWR-only, Ku-pol, and All-obs. In terms of correlation, the volumetric snowfall rate (r = 0.95) and snow water equivalent rate (r = 0.92) were best retrieved by the Ku-pol method, while the DWR-only method had the lowest magnitude bias for these parameters (−31 % and −8 %, respectively). The methods that incorporated DWR also had the best correlation to particle size (r = 0.74 and r = 0.71 for DWR-only and All-obs, respectively), although none of the methods retrieved density particularly well (r = 0.43 for All-obs). The ability of the measurements to retrieve mean aspect ratio was also inconclusive, although the polarimetric methods (Ku-pol and All-obs) had reduced biases and MAE relative to the Ku-only and DWR-only methods. The significant biases in particle size and snowfall rate appeared to be related to biases in the measured DWR, emphasizing the need for accurate DWR measurements and frequent calibration in future D3R deployments.

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Section: D3rmentioning

confidence: 99%

Snow Microphysical Retrieval from the NASA D3R Radar During ICE-POP 2018

Munchak

Schrom

Helms

et al. 2021

Preprint

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“…This can lead to savings on size, weight and power. Another example could be the NASA D3R which operates in Ku-band and has parabolic reflector antenna [19], [20], [23], [21], [22], [24]. It has a beamwidth of 0.9 deg in both dimensions and the dish size is approximately 1.83m in diameter.…”

Section: ) Dimensionsmentioning

confidence: 99%

A MIMO approach for Weather Radars

Kumar,

Chandrasekar,

Kelly

2021

Preprint

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This article develops the multiple-input multipleoutput (MIMO) technology for weather radar sensing. There are ample advantages of MIMO that have been highlighted that can improve the spatial resolution of the observations and also the accuracy of the radar variables. These concepts have been introduced here pertaining to weather radar observations with supporting simulations demonstrating improvements to existing phased array technology. Already MIMO is being used in a big way for hard target detection and tracking and also in automotive radar industry and it offers similar improvements for weather radar observations. Some of the benefits are discussed here with a phased array platform in mind which offers quadrant outputs.

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“…With the simulator, we have the capacity to evaluate the newly developed polyphase code for weather radar in a controlled environment without actually physically testing on the radar platform. The parameters for simulation are the values from the NASA D3R weather radar system (Ku band) which has recently been upgraded with new IF sub-systems [27], [28]. A brief specifications of this radar are given in Table I.…”

Section: Modeling Of Phase Noise Errorsmentioning

confidence: 99%

Intrapulse Polyphase Coding System for Second Trip Suppression in a Weather Radar

Kumar

Chandrasekar

2020

IEEE Trans. Geosci. Remote Sensing

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This paper describes the design and implementation of intra-pulse polyphase codes for a weather radar system. Algorithms to generate codes with good correlation properties are discussed. Thereafter, a new design framework is described, which optimizes the polyphase code and corresponding mismatched filter, using a cost/error function, especially for weather radars. It establishes the performance of these intra-pulse techniques with specific application towards second trip removal. The developed code is implemented on NASA D3R, which is a dual-frequency, dual-polarization, Doppler weather radar system.

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Performance trade-offs and upgrade of NASA D3R weather radar

Cited by 15 publications

References 6 publications

Snow Microphysical Retrieval from the NASA D3R Radar During ICE-POP 2018

Snow Microphysical Retrieval from the NASA D3R Radar During ICE-POP 2018

A MIMO approach for Weather Radars

Intrapulse Polyphase Coding System for Second Trip Suppression in a Weather Radar

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