Author Archive

Medieval Map of the known world 1450 and the Blue Marble comparison image
Jan 17, 2014Fra Mauro’s Mappamundi

Long before the famous Earthrise photo taken by Apollo astronauts, creating an image or map of the entire known world was a singular human endeavor. Imagine a half a millennium earlier when only those who had traveled could describe distant lands. Imagine watching the hustle and bustle of merchants and sailors returning to the port of Venice. What stories could they tell to paint a portrait of our planet?

newly established black mangrove grows amid salt marsh plants north of St. Augustine, Florida
Dec 30, 2013Landsat Satellite Sees Florida Mangroves Migrate North

Cold-sensitive mangrove forests have expanded dramatically along Florida’s Atlantic Coast since the mid-1980s, as the frequency of killing frosts has declined, according to a new study based on 28 years of satellite data from the NASA-USGS Landsat program.

Landsat 8 and 1894 map dissolve image of San Francisco Bay area
Dec 23, 2013Northern San Francisco Bay, 1894

Maps often convey our relationship to the world. In this map of the northern San Francisco Bay and surrounding environs, the early development of the region is recorded in detail. The full and arduous title of this map is “Map showing portions of Alameda and Contra Costa counties, city and county of San Francisco, California, carefully compiled from official and private maps, surveys and data.”

Map of Sicily from 1791 by William Heather
Dec 6, 2013Sicily, from W. Heather & Co.’s A New Chart of the Mediterranean Sea, 1797.

Maps often help us manage our world. In 1797, when cartographic engraver and chart publisher William Heatheri released his New Chart of the Mediterranean Sea, he had the needs of sea merchants foremost in mind.

Geographia: From Antiquity to the Space Age
Nov 21, 2013Geographia: From Antiquity to the Space Age

From the petroglyphs of ancient societies to the stunning views of our planet from space, humans have endeavored to visualize and accurately map our world. As early geographers recorded the experiences from travelers and merchants, they created lists of places and geographic features.

Aug 21, 2013After a Fire, Before a Flood: NASA’s Landsat Directs Restoration to At-Risk Areas

While the 138,000-acre Silver Fire still smoldered in New Mexico, forest restoration specialists were on the job, analyzing Landsat data to determine where to focus restoration efforts.

Jul 9, 2013Eco and Bio Archive

Jun 3, 2020 • NASA Fosters Innovative Ways to Understand Biodiversity NASA has funded four projects to create new, virtual portals to share a wealth of biodiversity information with land stewards around the world. May 28, 2020 • Meet Dr. Eric Bullock Dr. Eric Bullock uses Earth observation data to explore the consequences of land […]

Jun 28, 2013Landsat 8 Data Processing and Archive System (DPAS)

The USGS is also developing the DPAS to manage the mission data transmitted from the LDCM observatory. The DPAS will be operated at EROS along with the rest of its Landsat data archive and it will consist of several subsystems: Storage and Archive (SA), Ingest System (IS), Subsetter System (SS), Image Assessment System (IAS), Level 1 Product Generation System (LPGS), and User Portal (UP). These subsystems will work together to ingest, store, and archive LDCM data and will also generate LDCM data products for distribution.

Jun 28, 2013Landsat 8 Mission Operations Center (MOC)

A flight operations team (FOT) will operate two computer systems within the MOC, the Collection Activity Planning Element (CAPE) and the Mission Operations Element (MOE). The CAPE will plan science data collection by building activity requests for the LDCM imaging sensors each day. The MOE will translate the activity requests into software command loads transmitted to the observatory.

ground system logo 2
Jun 28, 2013Landsat 8 Ground System

The Landsat 8 Ground System includes all of the ground-based assets needed to operate the Landsat 8 observatory. The primary components of the Ground System are the Mission Operations Element, Collection Activity Planning Element, Ground Network Element, and the Data Processing and Archive System.

Relative Spectral Response
Jun 28, 2013Spectral Response of the Operational Land Imager In-Band, Band-Average Relative Spectral Response

The band-average relative spectral radiance responses of the Operational Land Imager (OLI) are provided.

OLI prelaunch signal-to-noise ratio
Jun 28, 2013Pre-launch OLI Performance

BATC has conducted robust testing of OLI performance in accordance with their proposal and contract. These prelaunch tests indicate that OLI performance meets specification with requirements exceeded in most cases.

drawing of OLI
Jun 28, 2013OLI Design

< OLI Requirements Pre-launch OLI Performance >   The OLI is a push broom sensor employing a focal plane with long arrays of photosensitive detectors (Irons & Dwyer, 2010). A four-mirror anastigmatic telescope focuses incident radiation onto the focal plane while providing a 15-degree field-of-view covering a 185 km across-track ground swath from the nominal LDCM […]

Jun 28, 2013OLI Requirements

< Operational Land Imager (OLI) OLI Design >   The OLI requirements specified a sensor that collects image data for nine spectral bands with a spatial resolution of 30 m (15 m panchromatic band) over a 185 km swath from the nominal 705 km LDCM spacecraft altitude. Key requirements include: a five-year design life; spectral band widths, center wavelengths, […]

TIRS telescope
Jun 27, 2013Spectral Response of the Thermal Infrared Sensor

< TIRS Design   In-Band, Band-Average Relative Spectral Response The band-average relative spectral radiance responses of the Thermal Infrared Sensor (TIRS) are provided here. These responses are based on measurements of the individual optical and electro-optical components of the instrument (Figure 1) combined to estimate the end-to-end instrument response. Filters: The filter spectral transmissions used […]

TIRS cryocooler
Jun 27, 2013TIRS Design

< TIRS Requirements TIRS Relative Spectral Response >   Like OLI, TIRS is also a push broom sensor employing a focal plane with long arrays of photosensitive detectors (Fig. 6). A four-element refractive telescope focuses an f/1.64 beam of thermal radiation onto a cryogenically cooled focal plane while providing a 15-degree field-of-view matching the 185 km […]

Jun 27, 2013TIRS Requirements

< Thermal Infrared Sensor TIRS Design >   TIRS requirements are specified in a manner similar to the OLI requirements. The specifications require TIRS to collect image data for two thermal infrared spectral bands with a spatial resolution of 120 m across a 185 km swath from the nominal 705 km Landsat altitude (Table 3). […]

Landsat 5
Jun 26, 2013Historic Landsat 5 Mission Ends

When the Landsat 5 satellite launched on March 1, 1984, it was expected to last at least three years. More than 29 years and 2.5 million images later, the U.S. Geological Survey issued the final command to the aged satellite on June 5, 2013, and officially decommissioned it on June 19.

launch vehicle assembly
Jun 19, 2013Launch Vehicle

The LDCM observatory will launch from Space Launch Complex-3E at Vandenberg Air Force Base aboard an Atlas V 401 launch vehicle built by the United Launch Alliance (ULA). This rocket is an evolved expendable launch vehicle capable of placing a 9370 kg satellite in low-Earth orbit. This capability offers ample mass margin for the LDCM […]

Thermal Infrared Sensor (TIRS)
Jun 19, 2013Thermal Infrared Sensor (TIRS)

TIRS Requirements > The Thermal Infrared Sensor (TIRS) measures land surface temperature in two thermal bands with a new technology that applies quantum physics to detect heat. TIRS was added to the satellite mission when it became clear that state water resource managers rely on the highly accurate measurements of Earth’s thermal energy obtained by […]