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9.5 Installation and Acceptance Testing

This section provides guidance for the installation and acceptance testing of upper-air monitoring systems; similar guidance for in situ sensors is provided in Section 8.2

The installation period is the optimal time to receive appropriate training in instrument principles, operations, maintenance, and troubleshooting, as well as data interpretation and validation. Meteorological consultants as well as some manufacturers and vendors of meteorological instruments provide these services.

Installation procedures specific to upper-air monitoring systems include the following:

  • The latitude, longitude, and elevation of the site should be determined using U.S. Geological Survey (USGS) topographical maps, other detailed maps, or a GPS instrument.

  • The orientation of antennas of the sodar, radar profiler, or radio theodolite systems should be defined with respect to true north. One recommended method is to use the solar siting technique [2] . This technique enables determination of true north at any location using a compass (or other pointing device suitable for measuring the azimuth angle to the sun), a computer program, the site latitude and longitude, and accurate local time.

  • The site should be documented as follows:

  • Photographs in sufficient increments to create a documented 360 panorama around the antennas should be taken. Additionally, pictures of the antenna installation, shelter and any obstacles that could influence the data should be obtained.

  • Photographs of the instrument, site, shelter, and equipment and computers inside the shelter should be obtained.

  • A detailed site layout diagram that identifies true north and includes the locations of the instrument, shelter, other equipment, etc. should be prepared. An example of such a diagram is shown in Figure 9-4. Additionally, it is recommended that the site layout diagram include the electrical and signal cable layout, and the beam directions of any remote sensor.

  • A vista table that documents the surroundings of the site in 30_ increments should be prepared. Vistas for the beam directions, if they are not represented by the 30 views (5), should be included. The table should identify any potential passive and active noise sources in each direction, and the approximate distance and elevation angle above the horizon to the objects. An example is shown in Table 9-5.

An acceptance test is used to determine if an instrument performs according to the manufacturer's specifications [2]. Manufacturer's procedures for unpacking, inspection, installation, and system diagnostics should be followed to assure that all components are functioning appropriately. All acceptance-testing activities should be documented in the station log. Once the system is installed, a final field check is needed to assure that the data are reasonable. This is best performed using collocated meteorological information from towers or other upper-air sensors. In the absence of these data sources, nearby upper-air data from the NWS radiosonde network, the NOAA profiler network, aircraft reports, National Center for Environmental Prediction (NCEP) high resolution mesoscale analyses, or other upper-air data can be used. It is important to have an individual trained in the interpretation of the data perform a thorough review of at least several days of data. This check is not meant to evaluate whether or not the data meet the manufacturer's data specifications, but is intended to identify problems such as:

  • Component failures
  • Incorrect or improper operating/sampling parameters
  • Antenna azimuth angles specified improperly or incorrectly measured
  • Siting problems (active and passive interfering noise sources)

Shortly after the installation and startup of an instrument, a system and performance audit should be performed. These audits will provide information for the qualitative and quantitative assessment of the performance of the system, as well as the adequacy of the standard operating procedures used for collection, processing, and validation of the data. To best assure that the data collected is of known quality, and that potential problems are identified early, it is recommended the initial audit be performed within 30 days of the start-up date.

Figure 9-4 Example Site Layout diagram

9.1 Fundamentals  
      9.1.1 Upper-Air Meteorological Variables  
     9.1.2 Radiosonde Sounding System  
     9.1.3 Doppler Sodar 
     9.1.4 Radar Wind Profiler 
     9.1.5 RASS  
 9.2 Performance Characteristics  
     9.2.1 Definition of Performance Specifications  
     9.2.2 Performance Characteristics of Radiosonde Sounding Systems 
     9.2.3 Performance Characteristics of Remote Sensing Systems  
 9.3 Monitoring Objectives and Goals  
     9.3.1 Data Quality Objectives  
 9.4 Siting and Exposure
 9.5 Installation and Acceptance Testing 
9.6 Quality Assurance and Quality Control 
     9.6.1 Calibration Methods  
     9.6.2 System and Performance Audits  
     9.6.3 Standard Operating Procedures 
     9.6.4 Operational Checks and Preventive Maintenance  
     9.6.5 Corrective Action and Reporting  
     9.6.6 Common Problems Encountered in Upper-Air Data Collection 
 9.7 Data Processing and Management (DP&M) 
9.7.1 Overview of Data Products  
     9.7.2 Steps in DP&M 
     9.7.3 Data Archiving  
 9.8 Recommendations for Upper-Air Data Collection 

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