MODIS/Terra Calibrated Radiances 5-Min L1B Swath 1km - NRT

The MODIS Level 1B Near Real Time (NRT) data set contains calibrated and geolocated at-aperture radiances for 36 discrete bands located in the 0.4 to 14.4 micron region of

electromagentic spectrum. These data are generated from the MODIS Level 1A scans of raw radiance and in the process converted to geophysical units of W/(m^2 um sr). Additional data are provided including quality flags, error estimates and calibration data.

Visible, shortwave infrared, and near infrared measurements are only made during the daytime (except band 26), while radiances for the thermal infrared region (bands 20-25, 27-36) are measured continuously.

The Shortname for this product is MOD021KM and is stored in the Earth Observing System Hierarchical Data Format (HDF-EOS). A typical file size would be approximately 110 MB (a day granule around 150MB and a night granule around 70 MB).

In this new version (Collection 6.1) of MOD021KM, an advanced technique is introduced to mitigate the crosstalk contamination issue among the LWIR PV bands
using data from lunar calibration events.

The electronic crosstalk contamination issue in the Terra long-wave infrared photovoltaic (LWIR PV) bands (27 -30), has existed since the beginning of the mission but become more noticeable during later half of the mission. The electronic crosstalk is where signal from each of the detectors among the LWIR PV bands can leak to the other detectors, producing a false signal contribution. This contamination has had a noticeable effect on the MODIS science products since 2010 for band 27, and since 2012 for bands 28 and 29.

Environmental information derived from MODIS L1B measurements will offer a comprehensive and unprecedented look at terrestrial, atmospheric, and ocean phenomenology for a wide and diverse community of users throughout the world.

See the MODIS Characterization Support Team webpage for more C6 product information at:

http://mcst.gsfc.nasa.gov/l1b/product-information

or visit Science Team homepage at:
http://modis.gsfc.nasa.gov/data/dataprod/

MODIS一级B近实时（NRT）数据集包含位于电磁光谱0.4至14.4微米区域的36个离散波段经过校准和地理定位的孔径辐射亮度。这些数据源自MODIS一级A扫描的原始辐射亮度，并在转换过程中以W/(m^2 um sr)的地球物理单位进行转换。此外，还提供了包括质量标志、误差估计和校准数据在内的附加信息。可见光、短波红外和近红外测量仅在白天进行（除波段26外），而热红外区域（波段20-25，27-36）的辐射亮度则连续测量。该产品的简称是MOD021KM，存储在地球观测系统分层数据格式（HDF-EOS）中。典型文件大小约为110 MB（日粒度数据约为150 MB，夜粒度数据约为70 MB）。在MOD021KM的新版本（集合6.1）中，引入了一种先进技术，利用月球校准事件的数据来减轻LWIR PV波段之间的串扰污染问题。自任务开始以来，Terra长波红外光伏（LWIR PV）波段（27-30）的电子串扰污染问题一直存在，但在任务的后期变得更加明显。电子串扰是指LWIR PV波段中每个探测器之间的信号可能泄漏到其他探测器，产生虚假信号贡献。自2010年以来，这种污染对MODIS科学产品产生了显著影响，特别是波段27；自2012年以来，对波段28和29的影响也变得明显。从MODIS L1B测量中得出的环境信息将为全球广泛且多样化的用户群体提供对陆地、大气和海洋现象的全面且前所未有的视角。更多信息请访问MODIS特性支持团队网页：http://mcst.gsfc.nasa.gov/l1b/product-information，或访问科学团队主页：http://modis.gsfc.nasa.gov/data/dataprod/。