NASA DAAC Data Services Now Accessible as an API Endpoint

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Are you looking to customize MODIS, GLAS, AMSR-E, or SMAP data? While customization options such as subsetting and reformatting are currently available through the NASA Earthdata Search web application, these services can now be accessed programmatically as a synchronous REST interface.

How does the API work?

Programmatic access to these data services is provided via an HTTPS URL. The programmatic access endpoint contains key-value pairs that utilize the Common Metadata Repository (CMR) to find the requested data, as well as the subsetting, reformatting, and reprojecting services to customize those data. When utilizing this API in a command line environment, the customized output is returned as either a single file or multi-file zip downloaded directly to your machine’s current working directory.

Programmatic access architecture

Architecture of the EOSDIS Service Interface. CMR and data processing services are called via programmatic API access. Source: https://developer.earthdata.nasa.gov/sdps/programmatic-access-docs

Why access data services programmatically?

While the NASA Earthdata Search application provides a comprehensive web-based search and order interface, you may be looking for a more direct access point for customized data. Using the new API feature, these data can now be easily accessed using a variety of approaches including URL transfer protocols (e.g. curl: https://curl.haxx.se/) and MATLAB readers (e.g. https://www.mathworks.com/help/matlab/ref/geotiffread.html). In addition, work is currently ongoing to provide OGC Web Coverage Service (WCS) compatibility, enabling data access through WCS-supported software such as ArcGIS, QGIS, and GeoServer.

Where can I learn more?

An overview guide to this API can be found at http://nsidc.org/support/how/how-do-i-programmatically-request-data-services. This guide walks you through the basic steps needed to construct the API, as well as resources to help you determine the customization options available for your data set(s) of interest. Comprehensive documentation provided by the API developers is also available on the Earthdata Developer Portal.

Comments? Concerns? Feedback?

Let us know! Email us at nsidc@nsidc.org to let us know how we can improve this API.

The Search Continues: NASA Tools to Help Display and Download Your Data

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The search for data can be daunting, but there are tools available to help you along the way. The purpose of this article is to describe two web-based tools, NASA’s Worldview and Earthdata Search, which can be used to work with datasets collected from NASA satellite missions. The tools can complement one another when searching for and visualizing some data, but are intended to serve different needs. Both tools can be used with a number of datasets available at NSIDC[1]. To illustrate the use of these tools, a fictional case study is presented, displaying how these web interfaces may be used in practice.

The first tool in this discussion is NASA Worldview. The Worldview tool is intended to serve as a platform to browse global satellite data in a near-real time setting. For many of the datasets available through Worldview, the latency (time difference between acquisition and availability) is on the order of just a few hours. Therefore, Worldview was designed to meet the needs of those with time-critical roles, but can also be useful for visualizing and inspecting data prior to downloading. For more guidance on using Worldview, please have a look at the NSIDC video tutorial, showing users how to view and download Soil Moisture Active Passive (SMAP) data available from NSIDC, or visit the NASA Worldview FAQ Page.

The second tool available to data users is NASA Earthdata Search. The Earthdata Search tool is intended to provide more thorough and detailed data ordering options. Many of the datasets accessible with this tool have the EOSDIS Service Interface (ESI) enabled, allowing a user to configure the data to match their spatial and temporal needs, the formats and projections to align with their software preferences, and access options appropriate for the volume of data ordered. Therefore, Earthdata Search is designed with a focus on data acquisition for research rather than browsing and monitoring, though some visualization is possible. For more guidance on using Earthdata Search, please have a look at the NSIDC video tutorial, showing users how to search for and order SMAP data available from NSIDC.


Fictional Tool Selection Case Study: Fire Service Incident Command Systems

Data and Tool Need #1:

“As a fire service emergency first responder to the November 2016 wildfires in Northern Georgia, I need to know:  a) where smoke plumes are traveling, b) where the density of those plumes reaches a hazardous threshold, c) current soil moisture, and d) any accessible large bodies of water to help fight the fire source.”

In this scenario using the NASA Worldview tool would be the optimum choice. The responder would have the ability to view visible imagery showing the plume trajectory and SMAP soil moisture, overlay an aerosol optical depth product for analyzing plume density, and could add Base Layers to show large bodies of water (Figure 1).

Figure 1. Looking at near-real time data for situational awareness

Figure 1. Looking at near-real time data for situational awareness. (Click for high-res)

Data and Tool Need #2:

“As a fire service emergency manager, I would like to commission a study looking at conditions which preceded the fires, so as to prepare for similar scenarios in the future. I need to analyze the soil moisture conditions for the three weeks leading up to the fires.”

In this case, using the NASA Earthdata Search tool is the best choice. The emergency manager will be able to search for a soil moisture product using temporal and spatial bounds (Figure 2), reformat the data if needed, subset using the bounds entered in the search tool (Figure 3), and choose a preferred download method (e.g. FTP pull, download links, download scripts).

Figure 2. Searching for soil moisture data

Figure 2. Searching for soil moisture data. (Click for high-res)

Figure 3. Downloading a subset of reformatted data.

Figure 3. Downloading a subset of reformatted data. (Click for high-res)

NSIDC recommendations: For visualizing near-real time data, look no further than NASA Worldview. The data are still available for download, and maps can be shared as a URL or acquired in a variety of image formats. You may still have quick visualization options for your data in Earthdata Search, but the value of the Earthdata search tool is configuring the data to save you time in your research-oriented analyses.

[1] The datasets available with these online tools will have a link on the NSIDC dataset landing page.

Applications of SMAP and Evapotranspiration Data: Webinar Series

If you are interested in Soil Moisture Active Passive (SMAP) data, we would like to bring your attention to an upcoming webinar series offered by the NASA Applied Remote Sensing Training (ARSET) Program that is focused on applications of SMAP and evapotranspiration data. This webinar series will help attendees learn about NASA soil moisture and evapotranspiration products and how to access and apply them for water resource management. Over the course of five weeks, attendees will learn how to monitor and manage water resources with techniques learned in training. The series will begin with an introduction to satellite missions and useful data sets. Next, trainers will demonstrate online portals for accessing data. The series will conclude with specific examples of how you can apply the data and modeled data products.

Webinar series details
Applications of Remote Sensing to Soil Moisture and Evapotranspiration
Dates: Thursdays, from September 1 to September 29.
Times: 11:30-12:30 or 18:00-19:00, Eastern Daylight Time (EDT).

Agenda:
Week 1: Introduction to Soil Moisture, Evapotranspiration, and an Overview of the SMAP Satellite Mission
Week 2: Applications of SMAP Data
Week 3: Accessing SMAP Data
Week 4: Landsat-based Evapotranspiration Estimates (METRIC) and Google Earth Engine Evapotranspiration Flux (EEFlux) Portal
Week 5: MODIS-based Evapotranspiration (ALEXI) and Soil Moisture and Evapotranspiration data from GLDAS/NLDAS

For more information and to register, please see:
https://arset.gsfc.nasa.gov/water/webinars/apps-et-smap

SMAP-Southeastern-US-flood

Surface soil moisture in the Southeastern United States as retrieved from NASA’s SMAP satellite observatory at around 6 a.m. on Oct. 5, 2015. Large parts of South Carolina appear blue, representing areas with saturated soil conditions and possible standing water resulting from heavy localized rains and flooding. Large-scale flooding was experienced all over South Carolina on Oct. 5-6, 2015. Credit: NASA/JPL-Caltech/GSFC

Cancelled: SMAP Short Course at EGU

Please note that this session has been withdrawn from the EGU program.

If you are interested in NASA’s Soil Moisture Active Passive (SMAP) data and attending the European Geosciences Union (EGU) meeting in April, we would like to bring your attention to a short course that is focused on the utilization of SMAP data. The goal of this short course is to provide an overview of the SMAP satellite mission and its soil moisture and freeze/thaw data products including information on the instruments, retrieval algorithms, datasets, calibration and validation, and end user applications. A hands-on portion will familiarize participants with SMAP data products – data access, file contents, processing and usage.

Short Course Details

Utilization of Science Data from the Soil Moisture Active Passive (SMAP) Mission
European Geosciences Union (EGU) General Assembly 2016, Vienna, Austria

Wednesday 20 April 2016, 17:30-20:00 / Room -2.61
Convenor: Eni G. Njoku, Jet Propulsion Laboratory, Pasadena, CA, USA
Co-Convenor: Siri Jodha Khalsa, National Snow and Ice Data Center, Boulder, CO, USA

SMAP radiometer global soil moisture

These maps of global soil moisture were created using data from the radiometer instrument on NASA’s SMAP observatory. Each image is a composite of three days of SMAP radiometer data, centered on April 15, 18 and 22, 2015. The images show the volumetric water content in the top 2 inches (5 centimeters) of soil. Wetter areas are blue and drier areas are yellow. White areas indicate snow, ice or frozen ground. Credit: NASA/JPL-Caltech/GSFC

All About SMAP Data: Upcoming Webinar

With the launch of the Soil Moisture Active Passive (SMAP) spacecraft and deployment of its instruments earlier this year, the long awaited NASA SMAP Mission is upon us and the NASA NSIDC DAAC will be distributing SMAP soil moisture, freeze/thaw, and carbon data in the coming months. Please join us in the upcoming NASA Earthdata Webinar “NASA’s Soil Moisture Active Passive Mission Data Products” on 14 May 2015, where the content and format of SMAP data will be presented.

The global, high-resolution data provided by SMAP will enable and enhance research and applications to:

  • link terrestrial water, energy, and carbon cycle processes
  • quantify net carbon flux in boreal landscapes
  • extend weather and climate forecast capabilities
  • develop improved flood prediction, drought monitoring, and agricultural productivity capabilities

Join the webinar for an introduction to SMAP data and to ask any questions from a SMAP data expert.

Webinar Details

NASA’s Soil Moisture Active Passive Mission Data Products

Thursday 14 May 2015, 02:00 PM – 03:00 PM, Eastern Daylight Savings Time (UTC/GMT-4)

To register, contact the host, Jennifer Brennan, at Jennifer.L.Brennan@nasa.gov.

SMAP Radiometer Brightness Temperatures

SMAP radiometer image from 31 March to 3 April maps surface microwave emissions as brightness temperatures in Kelvin, with strong emissions in reds and weaker emissions in blues. Vegetated rainforests and dry deserts show strong emissions; Greenland and Antarctica have weak emissions. Credit: NASA/JPL-Caltech/GSFC