Barnes MMR reflected radiance from calibration panels, adjusted for sun angle

Surface reflectance factors, radiances, and temperatures were measured with a Mast-borne Modular Multiband Radiometer (MMR), predominantly in the solar principal plane, with nadir and off-nadir, view-zenith angles. The MMR was mounted on a portable mast in order to achieve a spatial sampling at a variety of sites as well as within each site. The portable mast alignment varied from the solar principal plane, to the azimuthal plane aligned perpendicular to the principal plane and aligned with the satellite azimuthal plane. Measurements were periodically collected with the MMR over a barium sulfate reference panel. Measurements were typically coordinated with aircraft and/or satellite overpasses. Solar radiation data at or near the specific site should be used to screen possible times of variable cloud cover.

The Surface Reflectance Measured with a Helicopter-borne MMR Data Set contains surface reflectance measurements in Landsat-TM bands at low to intermediate altitudes. The helicopter operated during all Intensive Field Campaigns (IFCs) and was available to support all satellite overpasses. The average flight time was 2 hours, during which an average of 11 FIFE sites plus one special target were covered. The helicopter missions were designed to provide a rapid means of intensively spectrally characterizing each FIFE site while providing FIFE study area coverage, and to provide an intermediate scale of sampling between that of the surface measurements and the higher altitude aircraft and spacecraft multispectral imaging devices. The Modular Multiband Radiometer (MMR) instrumentation was chosen to provide compatibility with surface-based radiometers and TM spacecraft sensors. Off-nadir measurements were made as a means of providing more accurate estimates of hemispherical reflectance and for use with bi-directional reflectance models.

A major aspect of the ground data collection effort in the SNF during the summers of 1983 and 1984 was the acquisition of helicopter canopy reflectance measurements. Canopy measurements were made at numerous sites with a helicopter-mounted Barnes multiband radiometer (MMR). MMR data were collected on ten dates in 1983 and eight dates in 1984. An additional Barnes radiometer was used to make simultaneous reference panel measurements. The canopy reflectance was derived from the canopy and reference panel measurements. All canopy and reference panel measurements were made under clear sky conditions. A majority of the helicopter measurements were taken at nadir view, although some off-nadir view angle measurements were taken primarily over black spruce and aspen sites. The reflectance factor is the ratio of radiant flux of the canopy measurement to that of the reference or calibration panel. Another component to be considered is atmospheric scatter, especially for aircraft measurements taken at higher altitudes. The amount of atmospheric scattering can be determined by using reflectance measurements of water targets. Reflectance measurements over water targets are included for all acquisitions in 1983. No water target measurements were taken during the 1984 field campaign. The summarized MMR data for both years, 1983 and 1984, are included in this data set. Fields include site ID number, number of observations averaged, code for altitude of instrument above the canopy, the time at which observations begin, the time at which observations end, sun zenith angle, sun azimuth angle, and reflectance for each of the bands (with standard deviations included within parenthesis). All measurements were taken at nadir, except where otherwise indicated. In 1984, MMR data were collected using off nadir view angles to measure the bi-directional reflectance characteristics of the forests.

The Advanced Microwave Precipitation Radiometer (AMPR) was deployed during the Tropical Rainfall Measuring Mission - Large Scale Biosphere-Atmosphere Experiment (TRMM-LBA); the second of three TRMM ground validation missions. AMPR data were collected at four distinct microwave frequencies (10.7, 19.35, 37.1 and 85.5 GHz) for the time period of January 23 through February 26, 1999. The geographic domain of the TRMM-LBA region was wholly within Brazilian Amazon Basin between 16 S to 6N latitude and 76W to 49 W longitude. The TRMM-LBA mission was to study convection over humid tropical land regions within the range of research-quality radar, lightning, radiosonde and raingage sites located in the Amazon Basin (Rondonia, Brazil).

Site averaged reflected radiance & reflectance from Barnes MMR from helicopter

This data set contains satellite-retrieved geophysical parameter files generated from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument on the National Aeronautics and Space Administration (NASA) Aqua satellite and the Advanced Microwave Scanning Radiometer 2 (AMSR2) sensor on the JAXA GCOM-W1 satellite. The geophysical parameters include daily air surface temperature, fractional open water cover estimates, vegetation optical depth, surface volumetric soil moisture, and atmosphere total column precipitable water vapor. The global retrievals were derived over land for non-precipitating, non-snow, and non-ice covered conditions.

The MCD19A3CMG Version 6.1 data product is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Multi-Angle Implementation of Atmospheric Correction (MAIAC) Vegetation Index Level 3 product produced daily in a 0.05 degree (5,600 meters at the equator) Climate Modeling Grid (CMG). The MCD19A3CMG product provides Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) at ground level in the absence of atmospheric scattering or absorption. The MCD19A3CMG Vegetation Index data product contains the following Science Dataset (SDS) layers: NDVI, NDVI normalized to a fixed geometry of solar zenith angle at 45° and nadir view, gap-filled NDVI, EVI, and EVI normalized to a fixed geometry of solar zenith angle at 45° and nadir view. A low-resolution browse image is also included showing NDVI created using a composite of all available orbits. Known Issues* Known issues are described in Section 6 of the User Guide. * An artifact was discovered in the EVI, NDVI, and NDVI_gapfill layers over the entire swath of southern polar region. The affected region shows false retrieval of data during the summer months. The artifacts occurred over permanently snow-covered areas where no meaningful NDVI retrieval is expected. A software fix was implemented for forward processing in June 2023. Existing data products will not be reprocessed. Affected dates are listed on the [Land Data Operational Products Evaluation Quality Assessment note](https://landweb.modaps.eosdis.nasa.gov/displayissue?id=187).* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=TerraAqua&as=61).

The Advanced Very High Resolution Radiometer (AVHRR) is a four- or five-channel scanning radiometer capable of providing global daytime and nighttime sea-surface temperature and information about ice, snow, and clouds. The sensor measures emitted and reflected radiation in five channels (bands) of the electromagnetic spectrum. The Site Average Reflectances Extracted from AVHRR-LAC Imagery Data Set consists of averages of pixel extracts from AVHRR-LAC (1 km resolution) scenes that overlay the FIFE site. Average radiances for dates are available for the five sensor wavebands and average reflectance and exoatmospheric reflectances are available for wavebands 1 and 2. Site averages are clustered in 1987 and during the summer of 1989. Some data are also available for early 1988. The AVHRR is capable of operating in both real-time or recorded modes. Direct readout data were transmitted to ground stations of the automatic picture transmission (APT) class at low-resolution (4x4 km) and to ground stations of the high-resolution picture transmission (HRPT) class at high resolution (1x1 km). Data recorded on board were available for processing in the NOAA Central Computer Facility. They included local area coverage (LAC) data which were from selected portions of each orbit with a 1x1 km resolution. The precision of satellite remote sensing estimates of surface reflectance (Hall et al., 1992), calibrated and corrected for atmospheric effects, was no worse than about 1 percent absolute.

This dataset represents multiple products archived at the multiple archive centers for the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra Satellite. This dataset is provided by NASA EOSDIS as a single point of entry for this suite of products. The provided access URL is link to EOSDIS's Earthdata Search tool with a pre-populated query that will bring up all products archived by EOSDIS with imagery provided by the MODIS instrument on Aqua.