A summary of C3VP data access.
Download File:C3VP Access InformationKeywords:Publication Date:
Download File:Disdrometer Derived Z-S Relations in South Central Ontario, CanadaAuthor(s):Keywords:Publication Date:
During the winter of 2006-2007, a number of in-situ and remote sensing precipitation measuring devices were operated at the Center of Atmospheric Research Experiment (CARE) site located near Egbert, Ontario about 30 km to the NW of the King City C-band operational dual-polarized radar. While the experiment was originally designed to measure winter precipitation for the Canadian Cloudsat/CALIPSO validation program (C3VP), the NASA’s Global Precipitation Measurement (GPM) ground validation program joined the efforts (cf. Petersen et al., 2007; this conference) bringing optical disdrometers (2D-video and two Parsivel disdrometers) and a multi-frequency radar. The CARE is a well- instrumented facility including Vaisala FD12P visibility sensor, Precipitation Occurrence Sensor System (POSS), the McGill University’s vertically-pointing X- band Doppler, and Hydrometeor Velocity and Shape Detector (HVSD).
In this paper we focus on two case studies, (a) the 6 December 2006 and (b) the 22 January 2007 snow events. Our objectives are six-fold, (a) to determine the characteriscs of snow size spectra, (b) to determine the bulk density of snow by comparing measurements of Parsivel and FD12P, (c) to estimate a density (ρ) versus ‘size’ relation for snow by comparing the 2D-video derived Zh measurements with the well-calibrated King City Zh data, (d) to compare the Zh between 2D-video, POSS and King City radars, (e) to estimate snowfall rate (SR) and equivalent melt water (MWR) rate, including comparison of melt water accumulations from 2D-video, POSS, and other ground-based instruments at the CARE site, and (f) to derive the Zh-SR and Zh-MWR power law relations from 2D-video and Parsivel data.
Download File:Profiler Data Sets for the NASA PMM CommunityAuthor(s):Keywords:Publication Date:
In support of NASA PMM, observations collected near Darwin, Australia, have been processed and data sets are being provided to the NASA PMM community to help validate and improved satellite retrieval algorithms and cloud resolving models.
The data sets are derived from surface rain gauges, a disdrometer, and vertical pointing profilers deployed at the Australian Bureau of Meteorology Research Centre (BMRC) wind profiler site near Darwin, Australia during the Tropical Western Pacific – International Cloud Experiment (TWP-ICE).
Download File:GPM Ground Validation System Level 3 Requirements for a Mobile Ka-/Ku-band RadarPublication Date:
Background and Purpose:
This specification defines the Level 3, system-level functional and performance requirements for NASA’s Global Precipitation Measurement (GPM) mission Ground Validation System Mobile Radar (GVSMR).
This document sets forth requirements for NASA’s GPM GVSMR including necessary ground validation measurement, data ingest, processing, archiving, and distribution.
The structure and functional breakdown of this document are used to organize the requirements only, and should not be interpreted as a physical architecture or allocation. Physical attributes and implementation approaches of the GVSMR are intentionally omitted from this document.
The GVS requirements presented in this document are traceable to the NASA GPM Level 2 Requirements.
Download File:D3R Technical SpecificationsPublication Date:
Detailed specifications document for the Dual-Frequency, Dual-Polar, Doppler Radar (D3R)
Download File:Scientific and Engineering Overview of the NASA Dual-Frequency Dual Polarized Doppler Radar (D3R) System for GPM Ground ValidationAuthor(s):Publication Date:
As an integral part of Global Precipitation Measurement (GPM) mission, Ground Validation (GV) program proposes to establish an independent global cross-validation process to characterize errors and quantify uncertainties in the precipitation measurements of the GPM program. A ground- based Dual-Frequency Dual-Polarized Doppler Radar (D3R) that will provide measurements at the two broadly separated frequencies (Ku- and Ka-band) is currently being developed to enable GPM ground validation, enhance understanding of the microphysical interpretation of precipitation and facilitate improvement of retrieval algorithms. The first generation D3R design will comprise of two separate co- aligned single-frequency antenna units mounted on a common pedestal with dual-frequency dual-polarized solid- state transmitter. This paper describes the salient features of this radar, the system concept and its engineering design challenges.
Download File:Realization of the NASA Dual-Frequency Dual-Polarized Doppler Radar (D3R)Publication Date:
This paper describes some of the novel technologies adopted in the realization of the NASA Dual-frequency Dual- polarized Doppler Radar (D3R) system for to be used by the GPM ground validation program. A description of the transceivers and major trades that lead to a solid-state architecture is presented. Other aspects enabling the design such as the waveform design and generation and the digital receiver is also described. Data measured from a similar power amplifier was used to estimate the expected range side lobe performance. An estimate of the expected sensitivity based on the transceiver parameters also presented.
Download File:GPM Ground Validation Science Implementation PlanKeywords:Publication Date:
The Global Precipitation Measurement mission (GPM) Ground Validation (GV) Science Implementation Plan (GVSIP) applies three overarching approaches to validation of GPM satellite constellation measurements, products, and algorithms. These approaches include:
- National Networks: Contributions of calibrated ground observations from operational and research instruments, regional and continental scale precipitation and hydrological products with associated error models, the development of downscaling models, and other related activities on large regional or continental scales;
- Physical Process studies and field campaigns: Contributions of targeted ground and aircraft measurements of cloud microphysical properties, precipitation, radar reflectivity, and radiances; modeling activities related to atmospheric simulation and retrieval algorithm testing; other relevant observations on local to regional scales
- Integrated hydrometeorology applications: Contributions related to assessment of satellite precipitation products at integrated hydrological sites using stream gauges and other hydrological measurements, formulation and application of downscaling methodologies, and analysis of the utility of satellite precipitation products for basin-scale water budget studies.
Download File:Validation Network Data Product User’s Guide - Volume 1 (TRMM)Publication Date:07/15/2014
This document provides a basic set of documentation for the data products available from the GPM Ground Validation System (GVS) Validation Network (VN). In the GPM era the VN performs a direct match-up of GPM’s space-based Dual-frequency Precipitation Radar (DPR) data with ground radar data from the U.S. network of NOAA Weather Surveillance Radar-1988 Doppler (WSR-88D, or “NEXRAD”). Ground radar networks from international partners are also part of the VN. The VN match-up will help evaluate the radar reflectivity attenuation correction algorithms of the DPR and will identify biases between ground observations and satellite retrievals as they occur in different meteorological regimes. A prototype of the required capability was developed using a match-up of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data with ground-based radar (GR) measurements from a set of WSR-88D sites along the southeastern coast of the U.S. TRMM data and their matching GR observations continue to be part of the VN operations in the GPM era. Volume 1 of the Validation Network Data User’s Guide describes the legacy TRMM-specific VN data set. Refer to Volume 2 of the Validation Network Data User’s Guide for a description of the GPM core and constellation VN data set.
Download File:MC3E Science PlanAuthor(s):Publication Date:
Science plan for the Mid-Continent Convective Clouds Experiment (MC3E), scheduled for the spring of 2011. This campaign will be conducted in cooperation with the Department of Energy's (DoE) Atmospheric Radiation Program (ARM). The field campaign will be conducted in south-central Oklahoma. The goal of the campaign is to contribute to the improvement of radar and microwave precipitation retrieval algorithms over land.