Ground Validation

Document Description

Overview of the Parsivel instrument:

  • Measures size and fall velocity of hydrometeors
  • Present weather sensor
  • Sampling area: ~50 cm2, varies with drop diameter
  • Number of size and velocity bins: 32 x 32 matrix
  • Drop size range: 0.06-24.5 mm
  • Velocity range: 0.05-20.8 m/sec
  • Operation period at Wallops Island: Spring 2002 - present
  • Manufacturer: OTT in Germany www.ott-hydrometry.de
Document Description

The NASA Snowflake Video Imager obtained nearly continuous data from 1 Dec 06 thru 7 Mar 07.

This presentation contains a summary for the entire data set, which is sorted into (a) priority days selected by GSFC investigators, and (b) non-priority days.

The results are displayed in images of DSD(t), which reveal (a) the large variability of snowflakes sizes during events and (b) the intermittency of snowfall – even during intense storms.

Document Description

The IDL procedure geo_match_z_pdf_profile_ppi_bb_prox_sca_ps.pro provides the capability to compute statistics and generate displays of PR and GV reflectivity from geometry-matched data produced by the GPM Validation Network prototype. These data are contained in a set of netCDF data files, one per “rainy” site overpass: a TRMM PR overpass of a ground radar (GV) site, with precipitation echoes present, referred to below as an “event”.

Document Description

The IDL procedure pr_and_geo_match_x_sections.pro provides the capability to interactively select locations for, and display, vertical cross sections of PR and GV reflectivity from geometry-matched data produced by the GPM Validation Network prototype. These data are contained in a set of netCDF data files, one per “rainy” site overpass (a TRMM PR overpass of a GV radar site, with precipitation echoes present). By default, the procedure also displays a vertical cross section of the difference (PR-GV) between the PR and GV reflectivity from the geo-matched data.

Document Description

This specification defines the Level 3 functional and performance requirements for NASA’s Global Precipitation Measurement (GPM) mission Ground Validation System (GVS). Overall, the GPM mission has defined a series of scientific objectives which include improvement in predicting terrestrial weather, climate, and hydrometeorology through a better observational understanding of the global water cycle. The purpose of the GPM GVS is rooted in the need for independent and objective evaluation of the precipitation products generated by the GPM mission.

Document Description

This specification defines the Level 3 functional and performance requirements for NASA’s Global Precipitation Measurement (GPM) mission Ground Validation System (GVS). Overall, the GPM mission has defined a series of scientific objectives which include improvement in predicting terrestrial weather, climate, and hydrometeorology through a better observational understanding of the global water cycle. The purpose of the GPM GVS is rooted in the need for independent and objective evaluation of the precipitation products generated by the GPM mission.

Document Description

The Light Precipitation Evaluation Experiment (LPVEx) planned for the Gulf of Finland in September and October, 2010 will seek to address this shortcoming by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of high latitude precipitation systems to drive the evaluation and development of precipitation algorithms for current and future satellite platforms.

Document Description

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.