Tracking the calibration stability and consistency of the 3.7, 11.0 and 12.0 μm channels of the NOAA-KLM AVHRR with MODIS

The NOAA-KLM satellites (NOAA-15 to 18) are the current polar-orbiting operational environmental satellites (POES) that carry the Advanced Very High Resolution Radiometer (AVHRR). This study examines the calibration stability and consistency of all three infrared channels (3.7, 11.0 and 12.0 μm) of AVHRR onboard NOAA-15 to 18. The short-term stability is examined from variations of the scan-by-scan gain response, while the long-term stability and calibration consistency are examined by tracking the trends of gain response and measured scene brightness temperatures. The relative differences of observed scene brightness temperatures among NOAA-15 to 18 AVHRR are determined using MODIS as a transfer radiometer based on observations from simultaneous nadir overpasses (SNO). Results show that variations of the scan-to-scan gain responses are within 0.10% under normal operational conditions, while long-term gain changes over six years from 2001 to 2006 vary from 2 to 4% depending on channel. Long-term trending results show that total six-year drifts in observed brightness temperature from NOAA-15 to 18 AVHRR are less than 0.5 K for a given scene temperature in the 250 to 270 K range for the 3.7, 11.0 and 12.0 μm channels, respectively. The calibration consistency is examined for a scene temperature range of 220 to 290 K. The temperature biases among NOAA-16 to 18 AVHRR are within ±0.5 K for the 11.0 and 12.0 μm channels. For NOAA-15 AVHRR, biases of –2.0 K at 11.0 μm and –1.5 K at 12.0 μm are found in comparison with others at the low end of the temperature range. For the 3.7 μm channel, relative biases up to a few degrees among NOAA-15 to 18 could be found at low brightness temperatures.     

Variability of chlorophyll concentration in the Arabian Sea and Bay of Bengal as observed from SeaWiFS data from 1997–2000 and its interrelationship with Sea Surface Temperature (SST) derived from NOAA AVHRR

Variability of chlorophyll concentration in the Arabian Sea and Bay of Bengal has been studied using SeaWiFS eight‐day average, 9 km processed data for the period 1997–2000. The interrelationship with sea surface temperature (SST) was studied with the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) derived, best SST product. The chlorophyll pattern shows in general high concentrations during February to March in the Arabian Sea and November to December in the Bay of Bengal. Year‐to‐year variations in temperature show an inverse relation with chlorophyll, at different locations, even on a monthly basis. However, the intraannual variability in chlorophyll at different locations shows differences in the relationship with SST. The Arabian Sea showed an inverse relationship at most of the locations, while a positive relationship was observed in the northwest region during October to December and an inverse relationship during January to April. The Bay of Bengal showed positive relationships at northeast locations, whereas no definite assessment could be made for other locations due to the narrow range of chlorophyll concentration.A longer time series (～10 years) will be required to establish a more concrete relationship but definitely consistent patterns are emerging from this study. The results form an additional dimension to the criteria for partitioning the ocean, required for global productivity or biophysical coupled modelling.     

Understanding the "Horizontal Dimension' of Molecular Evolution to Annotate, Classify, and Discover Proteins with Functional Domains

Protein evolution proceeds by two distinct processes: 1) individual mutation and selection for adaptive mutations and 2) rearrangement of entire domains within proteins into novel combinations, producing new protein families that combine functional properties in ways that previously did not exist. Domain rearrangement poses a challenge to sequence alignment-based search methods, such as BLAST, in predicting homology since the methodology implicitly assumes that related proteins primarily differ from each ot...     

用Visual C~( )实现旧代码向Windows应用转换的几种方法

VisualC 是目前对Windows进行应用程序开发的最好工具 ,在软件工程开发中得到了越来越广泛的应用。从其它开发环境转到VisualC 开发环境 ,会存在原有应用程序向Windows应用转换的问题 ,本文主要介绍在VisualC 中实现这种转换的几种方法。     

辽宁小麦种植方式现状及发展

目前辽宁省以小麦为前茬的麦复粮油菜种植技术有了很大的发展,８０：８０、８０：１００、８０：１２０的米麦间复套种成为主要的种植方式。为了争取农时并获得全年增产,应改革播种技术,解决间复套种与农业机械的配合问题。今后还应加强复种技术的研究,加强中早熟作物品种的选育工作,以解决辽宁省麦粮复种下茬作物产量较低的问题。     

基于现有软件进行中文简繁体转换的方法

本文简单介绍中文简繁体转换方式的演变历程，详细描述在现有转换工具的基础上进行简繁体转换的过程和方法．全面分析现有转换工具目前存在的各种问题和导致这些问题的可能原因，完整说明准备和优化转换对照表的过程、方法、原则和须考虑的事项．以及对转换过程进行改进和优化的方法。     

基于现有软件进行中文简繁体转换的方法

本文简单介绍中文简繁体转换方式的演变历程,详细描述在现有转换工具的基础上进行简繁体转换的过程和方法,全面分析现有转换工具目前存在的各种问题和导致这些问题的可能原因,完整说明准备和优化转换对照表的过程、方法、原则和须考虑的事项,以及对转换过程进行改进和优化的方法。     

(t,n)门限签名中的阈下信道及其安全性分析

论文介绍了LHL(t,n)门限签名方案中宽带阈下信道的构造方法,研究发现该方案中存在阈下收方伪造LHL签名的缺陷,进而给出了阈下收方伪造LHL签名的计算方法。     

生活形态研究与设计艺术关系的辨析

随着产品设计越来越关注固定人群的生活方式,反映和满足特定人群的特定需求的产品在设计领域逐渐凸显出来。把握生活形态研究和设计艺术两者的关系,让产品更加趋于特定人群的需求。从而使产品在使用的过程中激发人们的联想,产生共鸣。     

SVPWM变频调速系统中电流检测和矢量转换电路的设计

本文简介了空间矢量脉宽调制变频调速系统，针对该矢量控制系统中存在矢量坐标转换这一非线性环节和电流检测环节，研制了一种高精度的快速电流检测和矢量转换电路，此电路从属于系统主控制器。通过将次电路从主控制器分离出来的方法，为主控制器节省了有效的处理时间。     

交流变频调速电梯系统设计和应用

电梯作为现代高层建筑的垂直交通工具,得到了快速发展,其拖动技术已经发展到了调频调压调速,其逻辑控制也由PLC代替原来的继电器控制。文章在已有的通用变频器的基础上,采用PLC对电梯进行控制,通过合理的选择和设计,提高了电梯的控制水平,并改善了电梯运行的舒适感,使电梯达到了较为理想的控制效果。     

MVC模式在储粮害虫查询与防治系统中的应用研究

首先分析了目前流行的MVC模式的工作原理和性能特点；然后基于MVC和浏览器／服务器（B／S）多层体系结构，在J2EE开发环境下采用JSF、Servlet、EJB等核心技术进行储粮害虫查询与防治系统的框架设计。     

十进制计算机的信息编码与模数转换

本文以十进制计算机运算原理为基础,主要讲述十进制计算机的信息编码与模数转换问题.