ER-2 Program Overview
NASA operates the ER-2s as readily deployable high altitude sensor platforms to collect remote sensing and in situ data on earth resources, atmospheric chemistry and dynamics, and oceanic processes. The aircraft also are used for electronic sensor research and development, satellite calibration and satellite data validation.
Types of Missions and Campaigns Performed by the ER-2
High resolution aerial photography is collected during earth imagery acquisition missions. A variety of camera systems and film types are in current use. Photography acquired at high altitudes on the ER-2s on long duration missions can image large areas of the earth's surface in a single flight. Multispectral scanner data and photography acquired coincidentally on ER-2 missions provide unique data sets for earth science research.
The ER-2 has played an important role in high altitude atmospheric research in recent years. The ER-2 has participated in several major aircraft campaigns to study the decrease in ozone over the Antarctic and Arctic regions. In August and September 1987 an ER-2 and the NASA Ames DC-8 were deployed to Punta Arenas, Chile to conduct overflights of the Antarctic. Results from this study provided data implicating man-made chemical compounds, specifically chloroflourocarbons, in the enormous ozone loss over the Antarctic region. Subsequent deployments have continued the study of the production and loss of ozone in the polar stratosphere. Atmospheric experiments were flown from Stavanger, Norway in January and February 1989 north of the Arctic Circle to investigate ozone loss in the stratosphere. In the period from October 1991 through October 1994 a series of ER-2 flights were flown out of Fairbanks, Alaska, Bangor, Maine and Christchurch, New Zealand to study the winter polar stratosphere. During these polar campaigns the ER-2 acquired atmospheric data with an array of up to eighteen sampling instruments on board the aircraft.
Recently a high level of flight activity has been directed towards determining the effects of a proposed fleet of stratospheric high speed transport aircraft. Background measurements of stratospheric chemistry have been compared to measurements of exhaust plumes of high altitude aircraft such as the Concorde and the ER-2.
Global Radiation Budget and Climate Change Research
Other atmospheric experiments were designed to promote the development of improved cloud and radiation parameters for use in climate models. These experiments coordinated satellite, airborne and surface observations to investigate the radiative properties and physical processes of clouds affecting global temperatures. The ER-2 is uniquely capable of providing data from the top of the atmosphere at fine spatial and temporal resolution.
Satellite Sensor Systems Development
Operating at 65,000 feet (19.8 km) the ER-2 acquires data above ninety-five percent of the earth's atmosphere. At this altitude the aircraft provides a stable platform for earth imagery acquisition, atmospheric research and electronic sensor development. The aircraft also yields an effective horizon of 300 miles (480 km) or greater at altitudes of 65,000 feet or higher. Consequently, ER-2 sensors acquiring earth imagery or conducting atmospheric sounding replicate spatial, spectral and atmospheric characteristics of data collected by earth observing sensors aboard orbiting satellites.
Since its inception the High Altitude Aircraft Program has assisted in the development of satellite sensors either through the operation of newly developed sensor prototypes or through simulation of proposed configurations with existing systems. In the early years of the program the U-2 flew prototypes of the Thematic Mapper (TM) and the Multispectral Scanner (MSS) now operating on Landsats 4 and 5. More recently the ER-2 has flown the Airborne Visible-Infrared Imaging Spectrometer (AVIRIS), a 224 band hyper-spectral scanner designed by the Jet Propulsion Laboratory in Pasadena. The MODIS Airborne Simulator, built jointly by Daedalus Enterprises and NASA, is being used extensively to develop mapping algorithms that will be applied to future EOS orbital data well into the next century. The Daedalus scanners have been configured with spectrometers for simulating Thematic Mapper, Ocean Color Imager and Advanced Very High Resolution Radiometer (AVHRR) data.
Collecting data with prototype instruments provides scientists the opportunity to develop methodology and algorithms for application to data sets collected with future orbiting systems.
The ER-2 frequently provides imagery for natural disaster assessments, including coverage of: the Mt. St. Helens eruption, Hurricane Iniki in Hawaii, the 1993 Mississippi floods, and the 1994 Northridge earthquake in southern California. The ER-2 supports the California Office of Emergency Services in developing new methods of delivering real-time imagery to fire fighters and other disaster relief agencies.