1. Earth Observation Data
  2. LANCE: NASA Near Real-Time Data and Imagery
  3. Responses to questions from the 2014 LANCE American Customer Satisfaction Index (ACSI) Survey

Responses to questions from the 2014 LANCE American Customer Satisfaction Index (ACSI) Survey

You asked, we answered! The Land, Atmosphere Near real-time Capability for EOS (LANCE) American Customer Satisfaction Index (ACSI) survey was conducted in October - November 2014. LANCE has responsed to questions and comments posed within the survey.

Thank you for taking part in the LANCE ACSI survey! Here are answers to some of your questions.

If we did not answer your question, please email us support@earthdata.nasa.gov.

What we learned:

  • Most users are very satisfied with LANCE.

It is encouraging for us to see so much positive feedback! Our goal at LANCE is to provide data and imagery in near real-time for applications that require timely information; your feedback and comments are very useful in helping us provide the best service we can.

  • Some data users would like data in alternative formats such as NetCDF and GeoTIFF.

We recognize that the NetCDF (network Common Data Form) data format is a commonly used format in many Earth science modeling and application communities. LANCE does not currently produce data in NetCDF format. For those using AIRS and MLS NRT data, OPeNDAP can be used to convert HDF-EOS to NetCDF format. Visit the AIRS OPeNDAP services and MLS OPeNDAP services.

ncl_convert2nc is an NCAR Command Language (NCL) command-line tool to convert HDF-EOS to NetCDF format. NCL is available for free as pre-compiled binaries for various UNIX systems or as source code. Learn more about the detail usage of ncl_convert2nc.

Tools for converting to GeoTIFF include: MODIS Reprojection Tool and HEG (HDF-EOS To GeoTIFF Conversion Tool). A list of tools available to work with HDF-EOS data can be found at:

Alternatively, if image representations of the data are sufficient for your application, Worldview can be used to export GeoTIFF images of LANCE data via the “Camera” button in the upper right corner of the application.

  • Access to the Infrared imagery over the poles during the winter months would be useful.

The infrared imagery (Brightness Temperature (Band 31) day and night) is available over the poles through Worldview and theGlobal Imagery Browse Services (GIBS).

Plans to make FIRMS more mobile / tablet friendly are underway. As part of these updates we will look at options for adding in more detailed overlays for maps.

  • Users want near real-time information on fire affected areas.

The standard MODIS burned area products [MCD45] are not available in near real-time. However, the MODIS Corrected Reflectance Bands 7-2-1 can be used in combination with the active fire /hotspots for identifying fire-affected areas in certain biomes, in near real-time. Read "Determining fire affected areas in near real-time using MODIS Corrected Reflectance 7-2-1 Imagery in Worldview" for more information.

  • In the survey we asked users who had selected to answer questions about Rapid Response, whether they have tried Worldview. 43% had tried Worldview, 21% would consider switching, 59% were not sure and wanted more information, and 20% would not consider switching.

In response to users who want more information on Worldview vs. Rapid Response, here are a few points:

  • Rapid Response will perform better in low bandwidth areas.
  • For those users that are not constrained by bandwidth, Worldview offers some features that are not available in Rapid Response. Using Worldview, users can:
    • Pan and zoom to any area on the globe.
    • View many more NRT imagery layers from MODIS, AIRS, MLS and OMI.
    • Search and order underlying data swath granules directly from Worldview.
    • Download imagery as GeoTIFF etc for any area-of-interest (250MB or less in size).
    • Overlay socioeconomic data supplied by SEDAC, orbit tracks provided by space-track.org, coastlines, boundary layers and graticules courtesy of ADD SCAR, OpenStreetMap, and PolarView.
    • Bookmark your area-of-interest using the permalink function.
  • Users would like near real-time RADAR/SAR imagery for pre/post flood mapping.

We are aware that a range of users would like radar / SAR and this will be considered.

Most frequently asked questions or comments, and our replies:

  • Is it possible to make data and imagery available more quickly?

We regularly look at ways to see if there are ways to make data and imagery available more quickly and over the last 5 years, a number of improvements have been made. Latency is defined as the time between satellite observation and data being available to the end user. In 2011, the EOS Data and Operations System (EDOS) implemented three major latency enhancements focused on decreasing the time taken to transfer data to the Level Zero Processing Facility (LZPF). These improvements resulted in a 51% overall latency improvement for Terra MODIS and a 24% overall latency improvement. LANCE aims to make Level 0, level 1 and level 2 data available within 3 hours; generally these latencies are exceeded. Imagery are generally available within approximately 4 hours – but varies according to location. Find out what the average data latency times for each instrument are.

  • I would like to see higher resolution data including Landsat data.
  • Currently there are no plans to add high-resolution data to LANCE.
  • Landsat is not generally available in near real-time although there is a Landsat Image Viewer that broadcasts Landsat data received from the Landsat 7 satellite when it passes within range of the ground station at USGS Center for Earth Resources Observation and Science (EROS).
  • Landsat data is distributed by the USGS via Earth Explorer.
  • I would like to see images of floods, forest and urban fires, volcanoes and snow cover.

Visit the Hazards and Disasters page to see what data and imagery might be useful for monitoring hazards and disasters. For specific events, go to the NASA Earth Observatory and/or browse by topic or the MODIS Rapid Response Gallery.

Questions / comments relating to Data

  • I am looking for machine-to-machine services.
  • Can I automatically set up a subscription service for geographic file-level subsets of data?
    • The answer above applies.
  • I would like to be notified when data on Vanuatu volcanoes or ash plumes are made available
    • You could create a permalink for Vanuatu in Worldview and check for imagery. Use the permalink button from the toolbar on the top left corner of Worldview.
    • You could also set up an email alert with NASA FIRMS to notify you when a hotspot is detected at Vanuatu.
  • Can the FTP archive be extended?

LANCE provides NRT data for timely applications. If latency is not a primary concern, users are encouraged to use the standard science products, which are created using the best available ancillary, calibration and ephemeris information. Science quality products are an internally consistent, well-calibrated record of the Earth’s geophysical properties to support science.

However we understand that after having found the dataset you desire, it would be preferable to be able to retrieve the older data without having to search for the dataset again. There are various ways you can do this, for example, you could search for data in Reverb, this will enable you to search for granules for multiple dates.

Once Worldview has been populated with the full archive of imagery, users will also be able to search for historic data for the same area-of-interest.

  • Can NRT data be formatted as gridded data not swath?

Formatting the data as gridded data instead of swath data would require data to be converted from swath to tile format which is not possible within the NRT timeframe. Tools such as the MODIS Reprojection Tool Swath (MRTSwath) can be used for this.

  • I always want data for the same area. Can you save my requested area for re-use?
    • For MODIS data: we encourage you to use the MODAPS Web Services (MWS) service for NRT, which permits machine-to-machine search for available products via date range and geographic area of interest, and provides FTP download URLs so users can download MODIS NRT products of interest. Find out more about the MODAPS Web Services API for LANCE-MODIS.
    • For imagery in Worldview, you can select your area of interest and then use a permalink to enable you to go back to that exact area. To modify the link so it goes to today’s date, remove the date function e.g. "&t=2015-02-24"

Fire Information for Resource Management System (FIRMS)

  • Can you flag whether the hotspots are detected at nadir (which is generally more accurate) or at the edge of swath?

The area of a MODIS pixel is nominally 1 km2 but grows away from nadir. To find the approximate pixel area, use the along-scan and along-track pixel dimensions found in the attribute information.

  • Can you make the active fire data (from FIRMS) available as a simple restful web service?

We are aware that a RESTful web service would be useful for some of our users and are looking in to options to implement it.

  • Can you mask static hotspots?
    • This should be feasible with MODIS Collection 6 data, which should be available in the next 6-18 months.
  • Some users question the accuracy of the MODIS hotspot fire detections.

There are a number of caveats that should be considered when using MODIS active fire /hotspot data. Fires will only be detected if they are burning when the satellite passes overhead; fires also need to be large enough and/or hot enough to be detected (see FIRMS FAQ “What size fires can be detected?” and MODIS Collection 5 Active Fire Product User's Guide version 2.5). MOD/MYD14 data from FIRMS in text file or shape formats does not contain information about cloud cover or missing data so depending on what sort of analysis is being performed it is sometimes possible to derive misleading (or even incorrect) results by not accounting for these other types of pixels.

Rapid Response

  • Updates to Rapid Response would be appreciated.
  • Users want optional lat/long lines and administrative boundaries overlaid on the RR subsets, and added as an option for download.

They will be considered as part of future updates. These features are available through Worldview.

  • Bandwidth is an issue for some users downloading data and accessing imagery.

We are aware that bandwidth is an issue for some of our users and we aim to keep file sizes small using compression. Rapid Response will be maintained for the foreseeable future to cater to low bandwidth users.

  • Can you restore the full archive of imagery that was lost during a disk failure?

The full archive of MODIS data are currently being processed as part of Collection 6, using updated algorithms. As part of this process, the full archive of MODIS imagery (from 2000 for Terra and 2002 for Aqua) will be made available first in GIBS and Worldview and then in Rapid Response. The approximate time frame for this is 6-18 months. Visit the News section of the MODIS Land website for updates.

  • Sometimes the images are divided into 2 or 3 images, of which one of the images has a complete different color and that looks very silly. Is it not possible to make from every region one complete image?

The MODIS instrument is on board the Terra and Aqua satellites, which are polar orbiting. The Terra satellite travels north to south, passing over the equator at 10:30am local time (and 10:30pm local time). Aqua moves in the opposite direction, south to north, passing over the equator at 1:30pm local time (and 1:30am local time). At high latitudes, adjacent imaging swaths overlap significantly but at the equator gaps occur between adjacent swaths. The regularly spaced gaps near the equator are due to lack of coverage between orbits. As a result, complete global coverage is achieved every one to two days. If imagery from one swath is available it will be used but sometimes imagery from 2 swaths are required to provide full coverage. When this happens there will differences in in the angles between the sun, the satellite and the Earth being imaged. This can result in different colors.

  • GPS locations are welcome when moving mouse on the screen. In this way I can find my hometown.

Coordinates are visible in Worldview (see bottom right corner of the screen).

Worldview

  • It could be great if you could define your own area of interest, e.g. 4 corner coordinates, and then automatically get that NRT cut-out available for download every day.

There are various options to achieve this now:

  • Use the permalink button from the toolbar on the top left corner of Worldview. Once you have this bookmarked you can modify the date or the image layers.
  • Using GDAL, users can pull one layer at a time for a selected area-of-interest. This can also be achieved using a GIS that is able to pull imagery through GIBS.
  • I’d like to be able to zoom in more.

The resolution of the imagery determines how far you can zoom in. Currently, the highest resolution data available in Worldview is 250m.

  • I’d like to see the full archive of MODIS imagery.

The full archive of MODIS data are currently being processed as part of Collection 6, using updated algorithms. As part of this process, the full archive of MODIS imagery (from 2000 for Terra and 2002 for Aqua) will be made available first in GIBS and Worldview and then in Rapid Response. The approximate time frame for this is 6-18 months. Visit the News section of the MODIS Land website for updates.

Last Updated: Jul 7, 2017 at 1:00 PM EDT