Attachment 5 - NATIONAL WEATHER SERVICE MANUAL 10-1402.pdf

Department of Commerce National Oceanic & Atmospheric Administration National Weather Service

NATIONAL WEATHER SERVICE MANUAL 10-1402

DECEMBER 8, 2023

Operations and Services

Upper Air Program NWSPD 10-14

RADIOSONDE OBSERVATIONS

NOTICE: This publication is available at: http://www.nws.noaa.gov/directives/

OPR: W/OBS31 (T. Day) Certified by: W/OBS3 (M. Hopkins) Type of Issuance: Initial

SUMMARY: This new manual provides procedures for upper air launch sites operationally using the AROS or MROS system.

MEHTA.AJAY.NAT

WAR.1365835825

Digitally signed by

MEHTA.AJAY.NATWAR.1365835825

Date: 2023.11.24 16:50:09 -05'00'

Ajay Mehta Date Director, Office of Observations http://www.nws.noaa.gov/directives/

NWSM 10-1402 DECEMBER 8, 2023

Radiosonde Observations

Table of Contents Page

1. Purpose and Scope

2. Documentation of Station Upper Air Program and Facilities

3. Official National Weather Service (NWS) Stations

4. Unforeseen Circumstances

5. Office Responsibilities

5.1 Upper Air Station

5.2 Regional Headquarters

5.3 National Weather Service Headquarters

6. Appendices Overview

7. Reference Documentation

8. Acronyms & Abbreviations

Appendices

A. Observation Instrumentation.............................................................................................................. A-1 B. UA Platform Familiarization...............................................................................................................B-1 C. Observation and Launch Preparation ..................................................................................................C-1 D. Cloud Observation and Weather Coding ........................................................................................... D-1 E. In-Flight Procedures ............................................................................................................................E-1 F. Data Transmission and Archiving ....................................................................................................... F-1 G. Quality Control of Data...................................................................................................................... G-1 H. Station Management .......................................................................................................................... H-1 I. Completion of Documentation (Forms) ................................................................................................ I-1 J. Surface Observation Systems ................................................................................................................J-1 K. Station Safety ..................................................................................................................................... K-1 L. Special Observations ...........................................................................................................................L-1

1. Purpose and Scope

Since the late 1930's the National Weather Service (NWS) has measured vertical profiles of pressure, temperature, relative humidity, wind direction and velocity through the use of balloon-borne radiosondes. This manual defines upper air operational requirements and general procedures applicable to all NWS stations.

All aspects of the radiosonde observation are covered, from preparing the radiosonde and balloon train to processing and disseminating upper air data. Also provided are procedures for completing upper air data forms and maintaining station upper air equipment.

This manual does not provide detailed system specific procedures for taking upper air observations with the Manual Radiosonde Observing Systems (MROS) or the Automated Radiosonde Observing Systems (AROS). For detailed procedures, please see the specific system’s user guide.

2. Documentation of Station Upper Air Program and Facilities

Each upper air station is responsible for maintaining accurate information files pertaining to its upper air program. The procedures and responsibilities for documentation of equipment, instrumentation, and observing programs are found in Appendix H, Appendix I, and NDS 10-13.

3. Official National Weather Service (NWS) Stations

The NWS participates in the WMO's World Weather Watch Program by maintaining and operating a network of radiosonde stations in the contiguous U.S. (69 sites), Alaska Region (13), Caribbean (1), and Pacific Region (9). This network of stations comprises approximately ten percent of the global network.

4. Unforeseen Circumstances

No set of procedures can cover all possibilities that can occur in an operational setting. The observer should adhere as closely as possible to this manual to handle situations not adequately covered by specific instructions, while using their best judgment. If procedures in this manual require changes or clarification, suggest them through the site supervisor, who in turn should forward the suggestion to the Regional Office Headquarters. If it is determined the suggestion is appropriate, the Region will forward the suggestion to Weather Service Headquarters (WSH) for possible inclusion into future manual or handbook revisions.

5. Office Responsibilities

5.1 Upper Air Station

Radiosonde observations are essential for producing accurate weather forecasts and warnings. The data also serves other purposes (e.g., aviation operations). Therefore, each observer will ensure observations disseminated are of the highest quality possible. When there is reason to believe that the accuracy or validity of the upper air data are questionable or erroneous, follow the procedures outlined in the system user guides for handling such situations. If ground equipment is believed to be the source of the problem, the observer should notify the electronics technicians for corrective actions. The upper air site manager is responsible for safety and quality. They are to ensure that the equipment and balloon inflation shelter are safe for site personnel and maintained regularly to provide timely, high-quality observations to data users. They also ensure that only qualified staff release weather balloons. Qualified personnel are defined as:

1) Those who have passed the applicable national program courses for the sounding system and safety.

2) Those who have demonstrated proficiency with the local site’s equipment and procedures.

5.2 Regional Headquarters

The Regional Headquarter offices are responsible for overseeing the operations at each upper air station in their Region. Specifically, they are responsible for the following activities:

a. Provides assistance in identifying and correcting station problems and coordinating with WSH in regard to such problems.

b. Maintains upper air station forms, containing station performance and logistical data for a minimum of three years.

c. Prepares and disseminates quarterly reports of station performance.

d. Develops NWS Supplements related to observing procedures and guidelines.

e. Conducts periodic station inspections to ensure compliance with the standards and procedures of this manual.

f. Obtain and have access to training center upper air examination records and certification results for reference.

g. Assists WSH with field tests of new equipment, software, and observational procedures.

5.3 National Weather Service Headquarters

The NWSH’s Office of Observations manages the upper air network in the development, acquisition, and management of cost-effective Upper Air observing technologies through the following activities:

OBS 31, Program Management Branch provides project and program management for life cycle support of the upper air observing system and ancillary systems. To carry out this responsibility, OBS31:

a. Procures balloons, radiosondes and other consumables for upper air stations and maintains logistical data.

b. Develops and maintains documentation related to operational upper air observations. This includes Policy Directives, handbooks, manuals, training materials and software installation instructions.

c. Prepares and maintains the upper air observer exams in coordination with the NWS Training Center.

OBS 32, Services Branch provides engineering, hardware and software sustainment, and configuration management for upper air observing systems and ancillary systems. To carry out this responsibility, OBS32:

a. Maintains, makes, and tests necessary changes to upper air software and hardware.

b. Develops specifications for all equipment, from balloons and radiosondes to ground tracking and data processing systems.

OBS 33, Evaluation Branch is responsible for testing and integration of new hardware and software and field support of the Upper Air program. To carry out this responsibility, OBS33:

a. Prepares reports on overall station and network performance.

b. Ensures the operational performance of all laboratory and field equipment.

6. Appendices Overview

Appendix A - Observation Instrumentation The purpose of this appendix is to familiarize observers with sounding components utilized by the NWS that form the flight train. This includes the radiosonde, balloon, twine, train regulators/unwinders, parachute and inflation gas used for lift.

Appendix B - UA Platform Familiarization The purpose of this appendix is to familiarize observers with the AROS and MROS Upper Air platforms and components used to collect, process, monitor, and disseminate upper air data.

Appendix C - Observation and Launch Preparation The purpose of this appendix is to discuss proper procedures for preparing and launching the flight train to ensure a successful flight. This includes balloon handling and inflation, preparing the flight train, radiosonde preparation, safety checks, and launch techniques. This includes utilizing a two-person technique in high winds.

Appendix D - Cloud Observation and Weather Coding The purpose of this appendix is to provide the necessary tables and specific instructions to format and enter the cloud and weather code in the MROS software.

Appendix E - In Flight Procedures The purpose of this appendix is to assist the observer with general post radiosonde release activities. See the specific system user guide for detailed instructions.

Appendix F - Data Transmission and Archiving The purpose of this appendix is to provide general information about the coded messages and transmitting and archiving all required data. For system specific information, please refer to the system user guide.

Appendix G - Quality Control of Data The purpose of this appendix is to provide general information regarding the quality control of data during and after an upper air flight. For system specific information, please refer to the system user guide.

Appendix H - Station Management

The purpose of this appendix is to provide station managers and observers information on their responsibilities for managing the upper air program and what documentation and software is required to be on site at an upper air station. This appendix also covers Upper Air Certification, the ordering of upper air consumables, accurate station data, and public requests for information regarding upper air projects.

Appendix I - Completion of Documentation (Forms) The purpose of this appendix is to provide instructions to observers on how to properly fill out certain upper air related forms and show examples of those forms.

Appendix J - Surface Observation Systems The purpose of this appendix is to give observers basic information about surface observation systems currently in use to obtain surface data near the launch site. In addition, this appendix provides information on what to do to obtain surface data in the event of equipment failure.

Appendix K - Station Safety The purpose of this appendix is to cover all aspects of station safety with emphasis on correct handling of hydrogen gas.

Appendix L - Special Observations The purpose of this appendix is to provide information for observers on what to do when special observations are requested, either internally or by external agencies.

7. Reference Documentation

Document Name Document Number

Date

Document Reference

Rawindsonde Meteorological Handbook: Rawindsonde and Pibal Observations

FMH-3

https://www.icams-portal.gov/publications/fmh/FMH3/00-entire-FMH3.pdf

Radiosonde Replacement System (RRS)

N/A https://www.weather.gov/media/upperai r/Documents/RWS_Build_3.4_User_M anual_%20071818.pdf

NWS GRAW MROS User Guide https://www.ops1.nws.noaa.gov/

NWS Vaisala MROS User

NWS Vaisala AROS User

WMO Manual on Codes

2019 https://library.wmo.int/doc_num.php?ex plnum_id=10235 https://www.icams-portal.gov/publications/fmh/FMH3/00-entire-FMH3.pdf https://www.icams-portal.gov/publications/fmh/FMH3/00-entire-FMH3.pdf https://www.icams-portal.gov/publications/fmh/FMH3/00-entire-FMH3.pdf https://www.weather.gov/media/upperair/Documents/RWS_Build_3.4_User_Manual_%20071818.pdf https://www.weather.gov/media/upperair/Documents/RWS_Build_3.4_User_Manual_%20071818.pdf https://www.weather.gov/media/upperair/Documents/RWS_Build_3.4_User_Manual_%20071818.pdf https://www.ops1.nws.noaa.gov/ https://www.ops1.nws.noaa.gov/ https://www.ops1.nws.noaa.gov/ https://library.wmo.int/doc_num.php?explnum_id=10235 https://library.wmo.int/doc_num.php?explnum_id=10235

8. Acronyms and Abbreviations

AC Alternating Current

AFSO Analyze, Forecast, and Support Office

ASCNO Ascension Number

AROS Automated Radiosonde Observing Systems

ASME American Society of Mechanical Engineers

ASOS Automated Surface Observing System

AWIPS Advanced Weather Interactive Processing System

AWS Automatic Weather Station

BILS Balloon Inflation Launch Shelter

BIT Built-In-Test

BUFR Binary Universal Form for the Representation of Meteorological Data

COTS Commercial Off-The-Shelf

EEPROM Electrically Erasable Programmable Read-Only Memory

EMRS Engineering Management Reporting System

FAA Federal Aviation Administration

FTP File Transfer Protocol

GFI Ground Fault Interrupter

GPS Global Positioning System

GUI Graphical User Interface

HISS Hydrogen Inflation Safety System

IAS International Activities Staff

IFGC International Fuel Gas Code

IFR Instrument Flight Rules

HOGEN Hydrogen Generation System

LAN Local Area Network

LED Light Emitting Diode

METAR Aviation Routine Weather Report

MIC Meteorologist in Charge

MIRS Management Information Retrieval System

MOU Memorandum of Understanding

MSL Mean Sea Level

MROS Manual Radiosonde Observing Systems

NCEI National Centers for Environmental Information

NCEP National Centers for Environmental Prediction

NFPA National Fire Protection Association

NLSC National Logistics Support Center

NM Nautical Miles

NRC National Reconditioning Center

NWS National Weather Service

OBS Observation Time

OGC Office of General Counsel

OIC Official in Charge

PDB Precision Digital Barometer

PTU Pressure, Temperature, Humidity

QC Quality Control

RADAT Radiosonde Observation Data

RAM Random Memory Access

RAOB Radiosonde Observation

RH Relative Humidity

RPU Remote Processing Unit

RRS Radiosonde Replacement System

RSOIS Radiosonde Surface Observing Instrument System

SDL System Data Logger

SDM Senior Duty Meteorologist

SDR Software Defined Radio

SID Station Identification Number

SPECI Aviation Selected Special Weather Report

SPS Sounding Processing Subsystem

TFR Temporary Flight Restrictions

UAIB Upper Air Inflation Building

UHF Ultra-High Frequency

UPS Uninterruptible Power Supply

USB Universal Serial Bus

UTC Coordinated Universal Time

VFR Visual Flight Rules

WBAN Weather Bureau Army Navy

WFO Weather Forecast Office

WMO World Meteorological Organization

WS Weather Service

WSH Weather Service Headquarters

A-1

APPENDIX A - OBSERVATION INSTRUMENTATION

1. Introduction ......................................................................................................................................... A-2

2. The Radiosonde .................................................................................................................................. A-2

2.1 Sensors .................................................................................................................................. A-3

2.1.1 Pressure .................................................................................................................. A-4

2.1.2 Winds and Location ............................................................................................... A-4

2.1.3 Temperature ........................................................................................................... A-4

2.1.4 Relative Humidity .................................................................................................. A-4

2.2 Allowances for Sensors......................................................................................................... A-5

2.3 Radiosonde Battery ............................................................................................................... A-7

2.4 Radiosonde Inspection and Preparation................................................................................ A-7

2.5 Radiosonde Storage .............................................................................................................. A-7

3. The Balloon......................................................................................................................................... A-7

3.1 Balloon Type......................................................................................................................... A-7

3.2 Balloon Performance ............................................................................................................ A-8

3.2.1 Inflation Lift Requirement ................................................................................................. A-8

3.3 Balloon Storage..................................................................................................................... A-9

3.4 Balloon Warranty................................................................................................................ A-10

4. Inflation Gases .................................................................................................................................. A-10

4.1 Hydrogen............................................................................................................................. A-10

4.2 Helium................................................................................................................................. A-10

4.3 Inflation Gas Supply ........................................................................................................... A-10

5. The Flight Train ................................................................................................................................ A-10

Figures A-1: Upper Air Radiosonde (GRAW) .................................................................................................... A-3 A-2: Upper Air Radiosonde (Vaisala) .................................................................................................... A-3 A-3: Radiosonde Sensor (Vaisala).......................................................................................................... A-6 A-4: Radiosonde Sensor (GRAW).......................................................................................................... A-6 A-5: GP26 Balloon Rolled Out on Inflation Table ................................................................................. A-7 A-6: Types of Train Regulators ............................................................................................................ A-11 A-7: NWS Radiosonde Flight Train ..................................................................................................... A-11

Tables A-1: Radiosonde Operating Conditions.................................................................................................. A-5 A-2: Allowances for Sensors .................................................................................................................. A-6 A-3: Balloon Storage Environment Requirements ................................................................................. A-9

A-2

1. Introduction

The purpose of this appendix is to familiarize observers with sounding components utilized by the NWS that form the flight train. This includes the radiosonde, balloon, twine, train regulators/unwinders, parachute and inflation gas used for lift.

2. The Radiosonde

A Radiosonde used by the NWS is a small, expendable instrument package that measures the vertical profile of meteorological variables from the surface to more than 30 km in altitude with a minimum ascension rate of 275 meter/min. The electronics that power the radiosonde include sophisticated meteorological sensors, signal processing electronics and a radio transmitter that transmits the data at specific frequency to a ground based receiving antenna and processing module. System software further processes, encodes, presents, and disseminates the data.

The Radiosonde is suspended below a large gas filled balloon referred to as a weather balloon or sounding balloon. As the radiosonde begins to ascend at approximately 300 meters per minute, sensors on the radiosonde measure temperature, relative humidity (RH) and pressure, along with wind speed positioning data provided by a Global Positioning System (GPS) at ~ 1 second intervals or less.

Radiosondes are equipped with temperature and relative humidity sensors and leverage GPS technology for wind, pressure, geopotential height, and horizontal location. Radiosondes may include an onboard pressure sensor that does not use GPS for pressure but still rely on GPS for wind, height, and location.

Radiosondes are battery powered and may include a train regulator/unwinder to support consistent radiosonde positioning and balloon tethering. Refer to the appropriate user guide for the system at the site for more information.

A Radiosonde observation can last in excess of two hours. During this time, the radiosonde can rise over 30 km and drift more than 250 km from the release point. During flight, the radiosonde can be exposed to temperatures as cold as -95 °C, RH values ranging from 0% to 100% and air pressures only a few thousandths of what is found at the earth’s surface. When the balloon has expanded beyond its elastic limitations (~10 meters in diameter) and bursts, the radiosonde returns to Earth. Due to the decreased size and weight (up to 113g) of radiosondes, they pose a very low risk to life and property.

Understanding and accurately predicting changes in the atmosphere requires adequate observations of the upper atmosphere. Radiosondes provide a primary source of upper air data and will remain so into the foreseeable future.

Refer to Figure A-1 and Figure A-2 for approved NWS radiosondes. To learn more about radiosonde type and operation, refer to the appropriate user guide for the system at the site for more information.

A-3

Figure A-1: Upper Air Radiosonde (GRAW)

Figure A-2: Upper Air Radiosonde (Vaisala)

2.1 Sensors

The Radiosondes integrated sensors include temperature, relative humidity, and pressure (if applicable).

When a radiosonde ascends, these sensors are linked to a battery powered radio transmitter that sends the sensor measurements to a ground receiver for processing. These sensors measure the environment as a function of changes in sensor electrical parameters such as resistance and capacitance. Refer to table A-1 for information on operating conditions.

2.1.1 Pressure

Depending on the system used at the upper air site, pressure is either derived from the radiosonde GPS height, temperature, and RH data or a pressure sensor will be located inside the radiosonde.

For systems with an integrated pressure sensor, as the pressure changes, the cell expands (decreasing pressure) or contracts (increasing pressure), changing the separation between two plates contained within the instrument housing. Refer to the appropriate user manual pertaining to the system at the site.

A-4

2.1.2 Winds and Location

A GPS unit inside the radiosonde provides horizontal location data (Latitude and Longitude) as well as height data. These values are then utilized in the calculation of Wind Parameters (speed, direction, u component, v component).

2.1.3 Temperature

The resistive film type sensor utilizes resistive materials like ceramic, platinum and mirrored surfaces to reduce the effects of solar radiation and increase response times due to low mass and heat capacity and are not influenced by thermal effects of the radiosonde housing. Refer to table A-1 for information on operating conditions.

2.1.4 Relative Humidity

This thin-film capacitor is protected against moisture and icing by either a mirrored capsule or an integrated heating function that provides protection from a wet bulb effect that may occur when the radiosonde experiences excessive icing during cold and wet conditions. Refer to table A-1 for information regarding radiosonde operating conditions.

Radiosonde Operating Conditions

Temperature

Type: Resistive Range: -90℃ - +60℃

Resolution: 0.01℃ Accuracy: < 0.4℃

Humidity

Type: Thin Film Capacitor Range: 0 to 100 %RH

Resolution: 0.1 %RH Accuracy: 4 %RH

Pressure (AROS)

Type: Silicon Capacitor Range: From surface pressure to 3 hPa

Resolution: 0.01 hPa Accuracy: < 1.0 hPa

*For MROS, pressure is calculated via GPS

Wind Speed

Method: Calculated via GPS Range: 0 to 200 m/s

A-5

Resolution: 0.01 m/s Accuracy: < 0.1 m/s

Wind Direction

Method: Calculated by GPS Range: 0 to 360°

Resolution: 0.01° Accuracy: < 1°

Table A-1: Radiosonde Operating Conditions

2.2 Allowances for Sensors

Upper Air radiosondes may differ slightly in size, weight, sensor configuration and materials depending on the system or vendor which could lead to slight measurement variations. The sensors should have no more than 5% data loss (per 5 minutes of flight time) for the duration of flight. Refer to the appropriate user manual that reflects the system at the site. See acceptable sensor allowances for NWS radiosonde sensor performance in table A-2.

Sensor Data

Allowable Measurement Error

Surface to 100 hPa

100 hPa to 10 hPa

Temperature (°C)

0.5°C

1.0°C

Relative Humidity (%)

5%

Pressure (hPa)

1.8 hPa

0.6 hPa

Pressure (hPa) AROS ONLY

1.8 hPa if pressure is >400 hPa and at temperature: (-95°C)-(+50°C)

≤0.6 hPa

If pressure is 400 hPa-4.0 hPa and at temperature: (-95°C)-

(+50°C)

Wind Direction (Degrees)

≤5.0° at ≤15 m/s

OR

≤2.5° at >15 m/s

≤5.0°

A-6

Wind Speed (m/s)

1.0 m/s

2.0 m/s

Table A-2: Allowances for Sensors

Figure A-3: Radiosonde Sensors (Vaisala)

Figure A-4: Radiosonde Sensors (GRAW)

A-7

2.3 Radiosonde Battery

Upper Air radiosondes are powered by lithium cell batteries that have up to 240 minutes of runtime.

Refer to state and local regulations for disposal instructions of electronic devices containing lithium batteries.

2.4 Radiosonde Operation Inspection and Preparation

Every radiosonde should be inspected for any physical damage or defects before attempting to perform a flight. Observers are to take extra care when handling the radiosonde and avoid touching, hitting, or bending the sensor boom. Depending on the system, powering up and initializing a radiosonde and the presentation of data displayed on the upper air workstation will vary. To learn more about radiosonde type and operation, refer to the appropriate user guide for the system at the site for more information.

2.5 Radiosonde Storage

Radiosondes must be stored in their original packaging in a dry, ventilated, clean and dust-free indoor storage space, and within the following environmental limits:

● Temperature: +5℃ to 40℃

● Relative Humidity: Below 85%

3. The Balloon

The NWS uses approximately 78,000 aerological sounding balloons annually to support NWS radiosonde observations required by the Office of Observations and its NWS Weather Forecast Offices.

The aerological balloons must survive a wide variety of launch and flight weather conditions and provide optimal ascent rates and burst altitudes necessary for reliable and accurate radiosonde observations.

3.1 Balloon Type

The NWS uses a GP26 (600g) or GP20 (350g) balloon at nearly all 92 Upper Air sites in the network.

This balloon type is designated as General Purpose (GP) followed by a two-digit numeric suffix designating the minimum bursting height in kilometers (26).

The GP26 (600g) balloon is a thin-skinned latex except at the neck where the latex is thicker (inside diameter between 3.073 cm to 4.52 cm) to accommodate an inflation nozzle, provide an ergonomic handle for person holding the balloon during a release and the means to attach the balloon with string to a flight train. When ready for release, the balloon has a diameter of about 1.5 meters with a wall thickness from 0.051 to 0.102 mm at sea level. As the balloon ascends, it reaches a diameter of up to 10 meters with a wall thickness of 0.0025 mm and a minimum bursting altitude of 26.0 km.

A-8

Figure A-5: GP26 Balloon rolled out on inflation table

3.2 Balloon Performance

Balloon performance is measured by the burst altitude and ascent rate. The optimal ascent rate is 275 to 350 meters/minute throughout the sounding. Performance is affected by the free lift, the thickness of the balloon skin, the air mass overlying the observing site, the weather conditions to which it is exposed, and the size and shape of the balloon envelope. Since most of these factors are uncontrollable, optimal performance for a given observation can best be determined by examining past balloon nozzle lift used under various surface weather conditions.

3.2.1 Inflation Lift Requirements The amount of hydrogen or helium most favorable for producing optimum performance should be ascertained before actual inflation of the balloon. Lift is defined as follows:

● Free Lift: The lift left after taking the payload into account. Free lift = Nozzle Lift –

Payload weight.

● Nozzle Lift: The lift measured at the balloon neck (without the payload attached) – i.e.

the Gross Lift less the Weight of the balloon itself. Nozzle Lift must always be more than the payload weight for obvious reasons.

● Gross Lift: The total lift provided by the Lifting Gas enclosed by the balloon (i.e. The weight of the displaced air less the weight of the lifting gas).

3.2.2 Inflation (AROS) The AROS automatically measures the volume of gas based on preconfigured settings. Refer to the AROS user guide for more information

Note: It is important to remember that the lift capabilities of hydrogen and helium differ. Hydrogen, the lighter of the two gases, lifts 31.8 grams per cubic foot at sea level while helium lifts 28.2 grams per cubic foot at sea level.

A-9

3.3 Balloon Storage

Care should be taken when storing aerological sounding balloons to ensure optimal performance and ensure maximum burst height. Balloons should be stored in their original sealed containers inside the office isolated from large electric motors or generators. The ozone emitted from motors and generators causes synthetic rubber to deteriorate. Ideal temperatures for storage should be in the range of 0 °C to 35 °C. Temperatures outside this range should be avoided during storage. Balloons shall not be stored in inflation shelters.

Balloons deteriorate with age and should be used in the order of their production dates to avoid excessive aging. As balloons are very delicate, no part of the balloon other than the neck should be touched with bare hands. Use soft rubber gloves, soft cotton gloves, or the plastic bag in which the balloon was wrapped when handling parts other than the neck. Refer to the table below for more detailed balloon storage requirements and exposure to various conditions.

Storage Environment Requirements

Condition Range

Air Temperature 0 °C to 35 °C (32 °F to 95 °F)

Air Relative Humidity 15% to 75%

Dusty 1 million particles per cubic meter, various sizes

Altitude -50.0 m to 3.0 km, MSL (Mean Sea Level)

Radiation Sunlight through office windows and ultraviolet light from office fluorescent lights

Table A-3 Balloon Storage Environment Requirements

A-10

3.4 Balloon Warranty

The balloon warranty period starts on the actual delivery date of the balloon to NLSC and lasts for 1 year. All aerological sounding balloons exhibiting out-of-box defects (e.g. pinholes, thin spots, patches, etc.) will be replaced if NLSC is notified of the defect within the warranty period.

4. Inflation Gases

In the NWS, there are two types of gas typically used to inflate weather balloons: hydrogen and helium gas.

4.1 Hydrogen

Although hydrogen gas is more volatile than helium (which is non-flammable), most land-based locations use hydrogen since it is only a fraction of the cost of helium. Safe practices are strictly adhered to when handling and using hydrogen. Hydrogen is either manufactured and bottled by a gas distributor or produced on site with a hydrogen generator.

4.2 Helium

Helium is safe and easy to use for inflating balloons. Unlike hydrogen, helium is an inert gas and does not pose a fire potential. However, helium costs are significantly higher than hydrogen.

5. The Flight Train

A flight train may consist of the following six components:

1. The Balloon: A GP26 (600g) / GP20 (350g) Aerological Sounding Balloon

2. A Light Stick (if required at Upper Air site): Light sticks use a non-toxic chemical to generate light. To activate a light stick, follow the activation instructions. Light sticks may only be used at MROS upper air stations that are within 5 nm of airports at night and during dim light conditions to allow aircraft pilots to see the balloon and flight train. Only a single light stick is to be used on a flight train. The AROS does not support light sticks.

3. A Parachute (if required at Upper Air site): A small parachute slows the descent of the radiosonde, minimizing the danger to people or property. Radiosondes with trajectories over bodies of water, deserts, and mountains may not require a parachute.

4. Twine: A length of twine is used to provide separation between the balloon, parachute (if used), and the radiosonde. Only NWS approved twine can be used.

5. Train Regulator/unwinder: During high surface winds, observers may be required to use a train regulator/unwinder. Train regulators/unwinders contain a spool of twine that slowly unwinds after balloon release. They enable the observer to launch a radiosonde in high winds without having to contend with many yards of slack twine. Depending on the system used at the site, a

A-11 train regulator/unwinder may be attached directly (see figure A-6). Refer to the appropriate user manual and Appendix C “Observation and Launch Preparation” for more information.

Figure A-6: Types of Unwinders / Dereelers

6. The Radiosonde: The instrument that measures meteorological variables and transmits data to a ground receiving and processing system.

Note: Do not attach any other components or payloads to the flight train, unless authorized by WSH.

A-12

Figure A-7: NWS Radiosonde Flight Train

B-1

APPENDIX B - UA PLATFORM FAMILIARIZATION

1. Introduction ..........................................................................................................................................B-3

2. Automatic Radiosonde Observing System (AROS) ...........................................................................B-3

2.1 Description .............................................................................................................................B-4

2.2 AROS Component Overview ................................................................................................B-4

2.2.1 AROS Radiosonde ..................................................................................................B-5

2.2.2 AROS Tracking ......................................................................................................B-6

2.2.3 AROS Automatic Weather Station (AWS).............................................................B-7

2.2.4 AROS Software ......................................................................................................B-7

2.2.5 AROS Operational Roles ........................................................................................B-9

3. Manual Radiosonde Observing System (MROS) ...............................................................................B-9

3.1 Description .............................................................................................................................B-9

3.2 MROS Component Overview..............................................................................................B-10

3.2.1 MROS Radiosonde ...............................................................................................B-11

3.2.2 MROS Tracking....................................................................................................B-12

3.2.3 MROS Sound Processing Subsystems/Ground Stations.......................................B-13

3.2.4 MROS Radiosonde Surface Observing Instrument System (RSOIS) ..................B-14

3.2.5 MROS Software....................................................................................................B-14

3.2.6 MROS Balloon Launch Sites................................................................................B-14

B-2

B-1: Automated Radiosonde Observing System (AROS / Autosonde / AS15) .......................................B-3 B-2: Autosonde AS15 Component Identification....................................................................................B-5 B-3: AROS Structural Areas....................................................................................................................B-5 B-4: Radiosonde with Unwinder (Vaisala)..............................................................................................B-6 B-5: AROS: Sounding Processing Subsystem (Vaisala) .........................................................................B-7 B-6: Vaisala Automatic Weather Station (AWS) ....................................................................................B-7 B-7: Color-coded Autosonde Components via Vaisala Autosonde Control Software ............................B-8 B-8: Autosonde Software Interfaces ........................................................................................................B-9 B-9: Vaisala MROS Components ..........................................................................................................B-10 B-10: GRAW MROS Components........................................................................................................B-11 B-11: MROS Radiosondes (Vaisala and GRAW) .................................................................................B-12 B-12: MROS Telemetry.........................................................................................................................B-13 B-13: MROS: Sounding Processing Subsystem (Vaisala) ....................................................................B-13 B-14: MROS: GS-E Ground Station (GRAW)......................................................................................B-14 B-15: High Bay ......................................................................................................................................B-15 B-16: BILS.............................................................................................................................................B-15 B-17: Kettle Launcher............................................................................................................................B-16 B-18: Inflation Table..............................................................................................................................B-16 B-19: Inflation Unit................................................................................................................................B-16

B-1: MROS Telemetry...........................................................................................................................B-12

B-3

The purpose of this appendix is to familiarize observers with the AROS and MROS upper air platforms and components used to collect, process, monitor, and disseminate upper air data. This appendix will focus on the Automatic Radiosonde Observing System (AROS) and the Manual Radiosonde Observing System (MROS).

2. Automatic Radiosonde Observing System (AROS)

Approximately 25% of the NWS Upper Air network uses a Commercial Off-The-Shelf (COTS) automatic radiosonde launcher to perform Upper Air soundings. The Vaisala Corporation is the vendor for all AROS systems. The AROS platform used operationally is the Vaisala AS15-CFG01 Autosonde (AS15) model. In addition, the terms AROS, Autosonde, and AS15 are interchangeable for the purposes of this appendix.

Figure B-1: Automated Radiosonde Observing System (AROS / Autosonde / AS15)

B-4

1. Gas supply: Hydrogen tanks, helium tanks, or hydrogen Generator (HOGEN)

2. Radiosonde Track Antenna (UHF Antenna)

3. Differential Global Positioning System (GPS) antenna

4. Flow meter

2.1 Description

The AROS is designed to perform soundings automatically for 24 consecutive soundings. The AROS consists of instrumentation to track and communicate with radiosondes for upper air meteorological observations, as well as electro-pneumatic equipment to automatically and/or remotely launch hydrogen or helium filled balloons to carry the radiosondes. The system also includes an Automatic Weather Station (AWS310) to provide surface observations to support radiosonde balloon launches. The AROS requires a bottled gas supply or hydrogen generation system (HOGEN) to provide lifting gas for radiosonde flights.

2.2 AROS Component Overview

The AROS consists of hardware and software components that function to prepare a radiosonde for flight, inflate and launch a weather balloon with flight train, receive and process the radiosonde telemetry into meteorological data, generate Upper Air data products, and transmit meteorological products to designated locations. The AROS components interface with each other to provide a seamless radiosonde observation, requiring minimal operator intervention. The AROS can provide up to 12 consecutive days of scheduled Synoptic soundings which can be controlled on-site or remotely via predefined network access.

B-5

Figure B-2: Autosonde AS15 Component Identification

For nomenclature purposes, the AROS consists of sections including a prefabricated structure (Shelter) resembling a shipping container, an attached balloon launching vessel (Launch Vessel), and an Automated Weather Station (AWS). The Shelter is divided internally into two distinct areas, the Operator Room and the Robot Room. The Shelter exterior includes gas measurement components and antennae. Figure B-3 illustrates major areas of the AS15 AROS.

Figure B-3: AROS Structural Areas

2.2.1 AROS Radiosonde

The Vaisala RS41-SGP radiosonde operates in the 403 MHz frequency range and is the sensor package used by the AS15 Autosonde. The radiosonde uses a thin platinum resistive

5. Launch Vessel

6. AWS310 Automatic Weather Station

7. Radiosonde storage and preparation module

8. Personal computer with AUTOSONDE control and MW41 sounding software

9. SPS311 Sounding Processing Subsystem

10. Main electrical panel

11. Safety fan

12. Uninterruptible power supply (UPS)

13. HMT330 series humidity / temperature transmitter

14. Logic control box

15. Compressed air storage tank with primary and secondary air compressors

16. Nozzle box

17. Rotating table with trays containing radiosondes and uninflated balloons

18. Ground check device R141-AS1

B-6 temperature sensor which provides quick response times and low solar radiation error. The relative humidity sensor is a thin film capacitor with a temperature sensor included to compensate for the effects of solar radiation while a flight is in progress. The RS41-SGP also contains a shock-resistant capacitive silicon pressure sensor and leverages GPS technology for wind calculations. Additionally, The RS41-SGP includes two long life lithium batteries and an unwinder specifically designed to support consistent radiosonde sensor boom positioning and balloon tethering.

1. Sensor boom

2. Power switch

3. Additional sensor interface connector

(not utilized by NWS)

4. Antenna

5. LED indicator light

6. Unwinder

7. Unwinder stick

Figure B-4: RS41-SGP Radiosonde with Unwinder (Vaisala)

2.2.2 AROS Tracking

The AROS is equipped with a tracking system that includes a directional radome UHF antenna installed on the roof of the Autosonde structure. The antenna contains six monopoles with corner reflectors and a cross dipole within a small dome. It has no moving parts and is designed for telemetry signals in the 400 MHz to 406 MHz frequency band. A GPS antenna also installed on the roof is used to obtain positional calculations. The signals received by the UHF and GPS antenna are processed by the Sounding Processing Subsystem that connects to a workstation inside the radiosonde operator room.

B-7

Figure B-5: AROS: Sounding Processing Subsystem (Vaisala)

2.2.3 AROS Automatic Weather Station

The NWS uses an Automatic Weather Station (AWS) to support the AROS platform. The AWS is a surface observation weather data collection system that measures, processes, and stores meteorological data. The AWS sensor array measures humidity, temperature, pressure, wind direction and speed. Observation data is collected by the central data logger which performs meteorological calculations and transmits the data to the workstation software for display and further processing by the user. For additional information on the AWS please refer to Appendix J “Surface Observation Systems”.

Figure B-6: Vaisala Automatic Weather Station (AWS)

2.2.4 AROS Software

The Autosonde interacts with three different Vaisala software interfaces: the Autosonde Control Software, the MW41 Sounding Software, and Network Manager (NM10) Software. The system consists of a workstation computer that is connected to the sounding processing subsystem that

B-8 processes pressure, humidity, temperature and wind finding data received from the radiosonde.

The system includes a mouse, keyboard and a display to monitor data.

The Autosonde AS15 Control Software allows a user to monitor the status of AROS components, alerts, events, and systems; perform loading procedures; create flight schedules;

grant launch permissions; and perform maintenance. The control software is the primary interface of the AROS hardware and has the capability to be controlled locally or from a remote location via a web browser.

1. Power source for Autosonde

2. Gas banks

3. Automatic Weather Station (AWS)

4. Compressed air system

5. UHF and GPS antennas

6. UPS

7. Gas flow measurement

8. Ground equipment

9. Robotics room

10. Launch vessel

11. Messages and reports

Figure B-7: Color-coded Autosonde Components via Vaisala Autosonde Control Software

The MW41 Sounding Software is the interface of the Vaisala tracking system associated with the AS15 Autosonde. Similar to RRS Workstation Software (RWS), this software displays flight data graphically and in tabular format while the flight is in progress. The MW41 software has the capability to be controlled locally or from a remote location via a web browser.

The Network Manager (NM10) Software is used to manage a network of AROS systems remotely through a web server interface. The NM10 software is capable of monitoring multiple data collection sites including surface weather observation sites, airport weather observation sites, and Autosonde sites. Depending on the site location, this software interface may or may not be used.

B-9

Figure B-8: Autosonde Software Interfaces

2.2.5 AROS Operational Roles

There are three operational roles associated with AROS: Site Operator, Remote Operator, and Remote Manager. Each role plays a vital part in Autosonde operations.

To learn more about the AROS platform, roles, and responsibilities, refer to the Vaisala AROS user guide.

3. Manual Radiosonde Observing System (MROS)

Approximately 75% of the NWS Upper Air network uses one of two COTS manual observing systems.

The two sounding systems are Vaisala and GRAW. Both systems meet all necessary functional requirements in order to produce consistent upper air observations.

3.1 Description

The MROS is designed to perform manual launches of hydrogen or helium filled balloons that carry radiosondes for tracking and communicating upper air meteorological observations. As with the predecessor systems, the MROS utilizes the Radiosonde Surface Observing Instrument System (RSOIS) or the Automated Surface Observing System (ASOS) for surface observations. A major distinction between MROS and the predecessor RRS system is that MROS antennas contain no moving parts, B-10 minimizing the risk of antenna-based mechanical issues.

3.2 MROS Component Overview

The MROS consists of hardware and software components that function to support the observer in preparing a radiosonde for flight, launching a weather balloon with a flight train, receiving and processing radiosonde telemetry into meteorological data, generating upper air data products, and transmitting meteorological products to designated locations.

Note: Since MROS is supported by two vendors, depending on which version of MROS your site is using, component configuration and instrumentation will vary.

1. Workstation Computer (w/display)

2. Sounding Processing Subsystem (SPS)

3. Ground Check Device

4. Radiosonde

5. GPS Antenna

6. UHF Antenna

Figure B-9: Vaisala MROS Components

B-11

1. Radiosonde

2. Omni Directional Antenna

3. Helical Antenna

4. GPS Antenna

5. Ground Station

6. Workstation (w/display)

Figure B-10: GRAW MROS Components

3.2.1 MROS Radiosonde

Regardless of vendor (Vaisala or GRAW), the MROS radiosonde performs measurement of the atmospheric profile of temperature, humidity, wind speed and wind direction. The MROS radiosonde uses GPS technology for wind, pressure, geopotential height, and horizontal location calculations and requires a ground check process. Compared to predecessor radiosondes, MROS radiosondes are not supplied with a mailbag; however, the radiosonde will still contain “Harmless Weather Instrument” labels. For more information on operational use of MROS radiosondes, refer to the appropriate user guide for the system at the site.

B-12

Figure B-11: MROS Radiosondes - Vaisala RS41-NG (left) and GRAW…