NASA Data Access and Interactive Viewers

a. Interactive Sites for finding data:

  • Worldview - This application allows you to interactively browse global satellite imagery within hours of it being acquired. Use the features described below to find interesting imagery, save and share what you find, and download the underlying data.
  • Earthdata - The Earth Observing System Data and Information System (EOSDIS) is a key core capability in NASA’s Earth Science Data Systems Program. It provides end-to-end capabilities for managing NASA’s Earth science data from various sources – satellites, aircraft, field measurements, and various other programs. For the EOS satellite missions, EOSDIS provides capabilities for command and control, scheduling, data capture and initial (Level 0) processing. These capabilities, constituting the EOSDIS Mission Operations, are managed by the Earth Science Mission Operations (ESMO) Project. NASA network capabilities transport the data to the science operations facilities.

Example: Access GPM IMERG Data Using Giovanni

Giovanni is a web-based application that allows for easy and quick exploration of many NASA data products (
On the Giovanni page you will see the following options:
Select Plot: Allows selection of analysis options
Select Date Range: Allows selection of time period
Select Region (Bounding Box or Shapefile): Allows section of a geographic region (By latitude-longitude, by map, or by shapefiles)
Keyword: Search data parameter by keyword
Plot data (bottom right): Make desired plot
Learn to select, analyze, visualize, and download IMERG data for a country or a river basin using Giovanni
Learn to generate -- map and time series of rain rates for a selected country or river basin

Time-averaged Rain Map

Go to (
Enter the following options
Keyword: Enter IMERG
Select Merged satellite-gauge precipitation estimate - Final Run (recommended for general use) (GPM_3IMERGM v03) Monthly
Select Plot: Maps: Time Averaged Map
Select Date Range: Month or Season and YYYY Range
Click the calendar icon and select ‘Seasons’, then select
Select 2015 June as the start date
Select 2015 August as the end year

Select Region (Bounding Box or Shapefile): Click on ‘Show Map’ to see the region

Example : Rain Rate Map for Mekong Basin (Select the following options)
Then Click on ‘Plot Data’ (at the bottom right)
You will get a map of rain rate averaged over June to August 2015
You can click the upper left ‘+’ symbol to zoom in.
Click on ‘Download’ and save the image as png, kmz (to view in Google Earth)

b. Sites for Downloading data

  • Mirador - This is an Earth science data search tool developed at the GES DISC for our data users. It has a drastically simplified, clean interface and employs the Google mini appliance for metadata keyword searches. Other features include quick response, spatial and parameter subsetting, data file hit estimator, Gazetteer (geographic search by feature name capability), and an interactive shopping cart.

c. Sites for evaluating data:

  • Giovanni - Giovanni is an on-line environment for the direct statistical intercomparison of geophysical parameters in which the provenance (data lineage) can easily be accessed. This user manual provides assistance on how to use Giovanni and information on Giovanni's data products and services.

d. NASA and Partner Data and Model Applications Products:


Freshwater Component Data Source/Product Resolution Data Access
Precipitation GPM IMERG 0.1x0.1, half-hourly, Daily,3-,5-,7-Day
Soil moisture SMAP 40 km, 3-day
Evapotranspiration Metric-EEFLUX 30m, 16-day
Groundwater GRACE 1x1, Monthly
Snow Cover MODIS Snow Cover 500m, Daily & 8-day


  • The NASA GSFC Flood Mapping Project produces automated global daily surface and flood water products at approximately 250 m resolution from the NASA MODIS sensors. Automated global mapping started in Nov 2011. We also produce surface water maps from Landsat imagery, when available for specific flood events.
  • The Global Flood Monitoring System is a NASA-funded experimental system using real-time TRMM Multi-satellite Precipitation Analysis (TMPA) precipitation information as input to a quasi-global (50°N - 50°S) hydrological runoff and routing model running on a 1/8th degree latitude/longitude grid.
  • Dartmouth Flood Observatory has a space-based measurement, mapping, and modeling of surface water for research, humanitarian, and water management applications.
  • Global Disasters Alert and Coordination System (GDACS) is a cooperation framework between the United Nations, the European Commission, and disaster managers worldwide to improve alerts, information exchange, and coordination after sudden-onset disasters.


  • Precipitation and Applications Viewer - This site provides a link to global precipitation data, a global landslide model, and global flooding data via Applications Programmer Interface, which can be used to automatically retrieve precipitation and related applications datasets and associated metadata for further processing by your tool of choice. Here we will outline the basic structure of requesting data from the API and interpreting the API response.

Water Management

  • GRACE Data Portal - This website provides an online interface to a series of data analysis routines written in the Interactive Data Language (IDL) by Sean Swenson. Computations are performed in real-time, using parameters specified by the user. End products are either maps or time series. Images are passed to the browser as PNG files of modest size, and can also be saved. Data obtained from this site should be referenced with wording such as "... data obtained from the University of Colorado”

  • South Asia Surface Water Modelling System - VIC (Liang et al., 1994) is a macroscale hydrologic model that solves full water and energy balances, originally developed by Xu Liang at the University of Washington. VIC is a research model and in its various forms it has been applied to most of the major river basins around the world, as well as globally. The VIC model is distributed under the GNU GPL v2.0 license. If you make use of this model, please acknowledge the appropriate references listed on the references page.