Texas: Transitioning to ALERT2Harris County updates flood-warning system with Campbell Scientific instruments

Alert2是一种现代通信协议，可提高洪水警告社区内的40年传统。Alert2旨在通过可靠地提供准确和及时的数据来提高传统警报防洪系统的性能。自2014年以来，Campbell Scientific提供了一系列Alert2变送器和定制解决方案，旨在满足客户的特定需求。新万博2019最新活动啊在2015年，哈里斯县洪水控制区（HCFCD）定制并安装了基于坎贝尔的Alert2升级到他们的防洪系统（FWS）。HCFCD与两个经验丰富的坎贝尔科学集成商合作，完成了新硬件上人员的安装和培训：David Haynes独特的AFWS设计，以及Telos服务的Don Van Wie。

背景
哈里斯县，德克萨斯州, is home to over four million people and is the third most populous county in the U.S. The goal of the Harris County FWS is to provide accurate, real-time rainfall and stage data to facilitate crucial decision making before, during, and after flood events. The Harris County FWS relies on 139 gaging stations placed throughout the county bayous and connected tributaries of 22 watersheds.

洪水预警网络最初由1982年安装的13站组成，增长，包括今天的139个HCFCD站。但是，在34年的系统扩张期间，出现了显着的痛苦。网络扩展，老化设备和维护实践在2007年创建了不可接受的数据丢失和质量。Campbell Scientific提供交钥匙FWS解决方案，包括Alert200和Alert210。新万博2019最新活动啊在Telos服务和独特的AFWS设计的帮助下，FWS从上到下进行了审查，该项目出发了竞争出价，最终解决方案是将所有设备替换为定制Campbell Alert2系统。在2015年的夏季和秋季，网络系统地用坎贝尔设备升级。网络最终由90个系统组成，该系统由AL200和无线电组成，而另外60个系统使用CR800 Datalogger。在升级过程中，HCFCD借机还有机会更新所有网站基础架构，包括新的天线，新的5 W太阳能电池板和站点排列。

使用OTT推动器和雷达传感器或雷达传感器或雷达传感器或从达到的汽车或坎贝尔科学的压力传感器进行手推车和Bayou水平。每次0.4英寸时都会传输降雨量。测量雨量，而阶段每次调整阶段则会通过0.10英尺的水。数据从远程站点传输到霍夫曼，加尔维斯顿和Clodine地区的三个蓝色水设计中继站。转发器站将测量数据传递给位于休斯顿Transtar和Harris County评估区的主要和备用蓝色水设计基站。一旦数据到达基站，它被摄入到Onerain的Contreatail软件中进行处理，归档和传播。（www.harriscountyfws.org.的）

系统性能分析
有很多方法可以评估洪水警告网络的成功。为了本文，我们将在正常条件（非暴暴事件）和升级期间，升级期间和升级后的峰值降雨事件中查看成功报告的百分比和升级到Alert2。为了分析静态条件期间的报告成功，HCFCD的Mark Moore审查了每日，预定的报告。2012年，只有82.0％的电池报告按预期到达。持续升级到系统上名义上将这种成功率增加到2014年的84.9％。但是，截至2015年底，将升级到Alert2增加到Alert2增加到99.5％的成功日常报告的百分比。

Understanding the availability of data during dry periods gives insight to network performance, however major rainfall events test the true reliability and resiliency of the system. One weakness of the original ALERT networks was lost data or transmissions due to message collisions (too many stations talking at once on a common frequency). Communication traffic in an ALERT system is a function of storm intensity and spatial extent; therefore, as the need to receive data increases, the chance of losing data also increases at the time when the data are most important. Prior to system upgrades, the overloading of radio frequencies in the HCFCD resulted in the loss of up to 60% of gage data during large events. For example on Memorial Day in 2015, Harris County received excessive amounts of rain, with some gages showing over 7 in. of rain in less than three hours. At this time there was only one ALERT2 test site installed, and the rest of the network was still legacy ALERT. As designed, the ALERT2 test site received 100% of its expected data reports during this extreme rainfall event. In comparison, only 65% of the expected reports were received from nearby legacy ALERT stations.

During the system upgrade to ALERT2, the HCFCD took steps to reduce data loss from collisions, including reducing background radio interference, installing correctly functioning equipment, and using ALERT2 concentrator repeaters. Since upgrading to ALERT2 with Campbell equipment, HCFCD can calculate how much traffic the system can handle before any performance degradation is observed, and can plan accordingly.

The ALERT2 network installed in Harris County was tested once during the installation process when the system was 35% legacy ALERT and 65% ALERT2. Near the end of October 2015, the remnants of Hurricane Patricia dropped 8 in. of rain in Harris County over a 24 hour period. During this storm event 99.6% of transmissions were successfully received from 90 ALERT2 stations. Since its completion the system was tested with a minor rainfall event in December 2015, and a moderate flood event in March 2016. During the minor rainfall event in December, 2.5 in. of rain fell over 48 hours. An analysis of the 15,000 reports generated during this event showed that 99.9% of expected reports were received.

3月6日至2016年3月11日,Harri部分地区s County received 2.5-7.4 in. of rain. Multiple watersheds experienced over-bank conditions during the storm event. Looking at the roughly 13,500 transmissions during this event, the average success rate for receiving data into the database at the base station during the storm event was 99.8%. During the worst hour of the storm, success fell to 98%.

系统维护
通过升级到Alert2硬件和更新基础设施，HCFCD已经能够减少量大延迟时间和预防性维护访问的长度。网站升级允许更容易获得设备。例如，技术人员不再需要从立管中移除发射器即可更换电池。检查传感器校准也更容易，因为技术人员可以直接连接到DCP并实时查看成品值。技术人员不再需要检查用于解码的消息的软件。硬件升级也使维修更容易。组件是模块化且易于更换的。技术人员不再需要拉动整个发射器。Plus Off架子传感器可用于更换损坏的单元而不需要专用圆形连接器。

这些升级有关技术人员的责任越来越多。例如，镀锡的电线可能会导致传感器问题;但是，在不需要任何特殊设备的情况下，布线问题更简单，无法在现场进行诊断和修复。多个电池连接器使电池交换更容易，可能会在不介入网站的情况下进行。直接，轻松访问SDI-12总线允许更容易地诊断问题。所有这一切都意味着在维护和维修上花费的资金较少。这笔钱可以花在进一步改善网络上。它也意味着在现场花费的时间较少，这很重要，因为许多地点都位于道路和桥梁上，而且在完成工作时需要转移流量。

Since field-based preventative maintenance takes less time, HCFCD has decided to add general site management to the visit, including tree trimming, weed eating, etc., to allow for discharge measurements during storm events and better rain capture. Harris County has been working to shift their mind set to include preventative maintenance in the office before a problem arises. For example, as each gage sends a status transmission six times a day, operators watch out for any gage that misses its four hour report. Sync status updates allow HCFCD to confirm that the transmitter is getting a good GPS signal, and repeated instances of high sync status values lead to investigation. Battery reports on a more regular basis allow them to diagnose a failing battery before it goes bad. They have removed six failed batteries from the field before those sites went completely out. In fact, because of the more regular battery reporting, HCFCD hasn’t had a site go inactive due to battery failure.

总之，氟氯烃卫生证券交易所工作人员相信坎贝尔科学警报2升级到FWS将允许该系统充分满足其提供准确，实时降雨和阶段数据，以便于洪水之前，期间和之后提供至关重要的决策事件。Campbell Scientific将感谢HCFCD的Mark Moore分享他对升级前和升级后的成功报告的分析。