GSFC Disdrometer Data

In support of NASA's Global Precipitation Measurement (GPM) Ground Validation program, two disdrometers have been placed on top of the roof of Building 33 at NASA GSFC, as well as three tipping-bucket rain gauges (see figure below).

All the instruments are connected to a data collection computer in a nearby control room which is also configured as an FTP server. The disdrometer data download is automated and daily plots of raindrop size distribution and integral rain parameters are produced daily.

Latest Disdrometer Images (updated hourly)

Rain	Joss #1	Joss #2	Parsivel #1	Parsivel #2
DSD	Joss #1	Joss #2	Parsivel #1	Parsivel #2

The figure below shows the latest (updated hourly) raindrop size distribution, updated hourly. In this plot, the y-ordinate is the drop size [mm], and the x-ordinate is time (one day per plot), while the colors represent the number of drops within each drop size interval.

The next figure, shows the integral rain parameters derived from the drop counts from a disdrometer (updated hourly). These parameters include rain rate [mm h^-1] and accumulation [mm] (red line), reflectivity [dBZ], liquid water content [g m^-3], concentration [# of drops per m³], total number of drops and the mass weighted mean diameter [mm].

Best data are from June 9, 2010 forward. Parsivel_02 data are only available to 28 May 2013, and the gauge data are to 03 Aug 2015.

Monthly Plots

Monthly Accumulations

Other Daily Plots

Daily Rain Plots
Daily DSD Plots

Daily Parsivel 1/2 Comparisons

We are currently beta testing a new Parsivel Model #2 instrument (Parsivel_02). Use these menus to view comparisons between the two instruments (Scatterplots, Time Series and PDFs).

Parsivel Scatterplot Comparisons

Daily Parsivel 1/2 Comparisons

We are currently beta testing a new Parsivel Model #2 instrument (Parsivel_02). Use these menus to view comparisons between the two instruments (Scatterplots, Time Series and PDFs).

Parsivel Scatterplot Comparisons
Parsivel Time Series Comparisons
Parsivel PDF Comparisons
Daily Text File

Latest Comparisons Raw Data Scatter Plots Time Series PDF

Comparisons with Collocated Gauge

Two Joss disdrometers and two Parsivel disdrometers are compared to Tipping-Bucket Rain Gauge Z.
Gauge Z is a virtual "best" gauge which is made of combination of the best info from 3 real gauges A, B and C.

Visit http://trmm-fc.gsfc.nasa.gov/trmm_gv/gauge/co_gauge_gsfc.htm for GSFC collocated gauge comparisons.

NOTE:

For safety's sake, the Joss disdrometer (JW_01) and three gauges (A, B & C) were removed from the roof on Aug 25, 2011 prior to Hurricane Irene. The Joss and gauges were moved back to the roof on Aug 29, 2011.
No data for JW_01,JW_02,Parsivel_01 & Parsivel_02 from Jun 29 to Jul 1, 2012 due to power outage caused by the derecho.
No data for Parsivel_02 from 20Z to 23Z on 29 Oct 2012 due to an instrument problem.
Parsivel_02 is not operational since Jun 2013.
Data updated to 03 Aug 2015. All gauges were removed from the roof later.

Daily Rain Plots
Daily Rain Data

Send questions or suggestions to David B. Wolff

Web Curator: Jianxin Wang
Technical Lead: Charanjit S. Pabla
NASA Official: David B. Wolff