Attachment 6 - NWS-J100-AR-RS001.pdf

NWS-J100-AR-RS001

Revision - E

SPECIFICATION

FOR NWS 403 MHz RADIOSONDES

DEPARTMENT OF COMMERCE

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL WEATHER SERVICE

OFFICE OF OBSERVATIONS

1325 EAST WEST HIGHWAY

SILVER SPRING, MD 20910

Table of Contents

1.0 3

2.0 3

2.1 3

3.0 4

3.1 4

3.1.1 4

3.1.2 4

3.2 4

3.2.1 4

3.2.2 4

3.2.3 6

3.2.4 11

3.2.5 12

3.2.6 12

3.2.7 13

3.3 14

3.3.1 14

3.3.2 14

3.3.3 15

3.3.4 15

3.3.5 15

3.3.6 15

4.0 1816

5.0 19

5.1 19

5.1.1 19

5.1.2 19

5.1.3 19

Acronyms

Glossary

Tables

Table 1: Transportation and Storage 3 Table 2: Radiosonde Operating Conditions 3 Table 3: RH Response Time 8

Figures

Figure 1 - Harmless Weather Instrument Label 14 Figure 2 – Additional Harmless Label 14 Figure 3 - NOAA Symbol 15

1.0 SCOPE

This specification defines the requirements for the 403 MHz radiosondes for the NWS Upper Air

Network radiosonde observing system.

2.0 APPLICABLE DOCUMENTS

The following documents form a part of this specification to the extent specified herein. In the event of conflict between the documents referenced herein and this specification, the contents of this specification shall be the superseding requirement.

2.1 Government Documents

Reference No. Title

FAA Regulations Title 14 CFR, Part 101

Moored Balloons, Kites, Amateur Rockets and Unmanned Free Balloons

National Telecommunications and Information

Administration (NTIA) Manual

Manual of Regulations and Procedures for

Federal Radio Frequency Management

(Redbook)

NWS-J100-AR-SP002 Specification for GPS Automatic Radiosonde

Observing System

3.0 REQUIREMENTS

General

This specification defines the requirements for the NWS 403 MHz radiosondes. Whenever a specific paragraph of this specification is referenced, all subparagraphs of the referenced paragraph shall also apply.

Radiosonde Description

The radiosonde is a lightweight all-weather instrument. The radiosonde measures or derives atmospheric pressure, temperature, relative humidity (RH), wind speed, wind direction, and determines three-dimensional position (latitude, longitude and altitude) after ground preparation and during flight. The radiosonde includes electronic circuitry and an antenna to receive and process signals from the Global Positioning System (GPS) and Global Navigation Satellite

System (GNSS), hereafter referred to as GPS, for measuring radiosonde velocity and radiosonde position. The radiosonde transmits these thermodynamic and position measurements via a

403MHz transmitter and antenna to the radiosonde ground system for data processing.

3.1 General Requirements

3.1.1 Identical Sensors and Physical Configuration

3.1.1.1 All radiosondes of a specific model delivered under the contract shall be identical in all respects, including pressure, temperature, and RH sensors, GPS receiver, associated circuitry and processing algorithms, and physical characteristics.

3.1.2 Radiosonde Calibration

3.1.2.1 The radiosonde shall be calibrated during manufacturing and shall meet measurement performance requirements without re-calibration prior to use.

3.2 Performance Requirements

3.2.1 General Performance Requirement

3.2.1.1 The radiosondes shall meet the performance requirements as specified herein, during preparation, launch, and flight operations.

3.2.2 Environmental Conditions

3.2.2.1 Transportation and Storage

3.2.2.1.1 The radiosondes shall be transportable by common carrier while exposed to the conditions listed in Table 1 in Vendor’s packaging.

3.2.2.1.2 The radiosondes shall meet all requirements in section 3.2 after exposure to all combinations listed in Table 1:

Table 1: Transportation and Storage

Condition Requirement applies to Range

Air Temperature: Transportation and Storage -40.0 degrees Celsius (ºC) to

+60.0ºC

Air RH: Transportation

5.0 percent to 100.0 percent

(condensing)

Air RH: Storage 15.0 percent to 75.0 percent

Altitude: Transportation -50.0 meters (m) to 15.0 kilometers

(km) Mean Sea Level (MSL)

Altitude: Storage -50.0 m to 3.0 km, MSL

Vibration: Transportation MIL-STD 810G, Method 514.6, Category 4 – Common Carrier

Mechanical Shock: Transportation MIL-STD 810G, Method 516.6, Procedure IV – Transit Drop

3.2.2.2 Radiosonde Operating Environmental Conditions

3.2.2.2.1 The radiosondes shall meet all requirements in section 3.2 under the complete range of radiosonde operating conditions listed in Table 2.

Table 2: Radiosonde Operating Conditions

Condition Range

Air Pressure: 2.0 hectopascals (hPa) to 1070.0 hPa

Air Temperature: -95.0ºC to +50.0ºC

Air RH: 0.0 percent to saturation

Wind vector: -165 meters per second (m/s) to 165 m/s

Hydrometeors (liquid and frozen precipitation):

0.25 mm to 300.00 mm instantaneous one minute rate per hour with a maximum velocity of 18 m/s

Ascent Rate: -9.0 m/s to +9.0 m/s

Altitude: -50.0 m to 38.0 km, MSL

Mean Spatially

Integrated Infrared Source Temperature:

30 degrees Kelvin (ºK) to 333 ºK

Solar Radiant Flux: 0.0 to 1358.0 Watts per meter2 (W/m2)

Mechanical Shock: up to 10.0 g for 25 milliseconds (ms)

3.2.2.2.2 Drop Shock

3.2.2.2.2.1 The radiosonde, when configured for a flight, shall meet the requirements in

Table 2, after it is dropped on to a concrete floor from a height of one meter. This is measured from the lower end of the transmitter-antenna assembly.

3.2.2.2.3 Temperature Sensor Lapse Rate

3.2.2.2.3.1 The temperature sensor shall minimize perturbations to air temperature measurements from wetting, icing and condensation.

3.2.2.3 Output Data Rate

3.2.2.3.1 The radiosonde shall transmit telemetry data, at a minimum, atmospheric pressure, temperature, relative humidity (RH), u and v wind components and radiosonde position (latitude, longitude and altitude) and shall be processed at a continuous rate of 2.0 seconds or faster.

3.2.2.3.2 The output radiosonde observation parameters shall be output to the ground system in accordance with NWS-J100-AR-SP002.

3.2.3 Measurement Requirements

3.2.3.1 General Measurement Requirements

3.2.3.1.1 The requirements specified herein shall be applicable to all measurements.

3.2.3.1.2 Measurement resolution shall conform to the resolution required to validate the measurement error.

3.2.3.1.3 The radiosondes shall meet the measurement requirements while encountering operating conditions identified in Table 2.

3.2.3.1.4 Atmospheric Thermodynamic Measurement Requirements

3.2.3.1.4.1 Unless otherwise specified, measurement requirements shall assume 5.0 m/s (+/-1 m/s) ventilation rate from surface to termination.

3.2.3.1.5 Sensor Orientation

3.2.3.1.5.1 The mounting of the external sensor(s) shall prevent unintentional sensor movement which degrades sensor performance during release and flight.

3.2.3.1.6 Thermodynamic Sampling Stability

3.2.3.1.6.1 The peak deviation from the mean of each thermodynamic parameter shall not be greater than ten times the minimum resolution for that measurement in the presence of constant thermodynamic conditions.

3.2.3.2 Pressure Measurement Requirements

3.2.3.2.1 Pressure measurements, directly measured or derived, shall meet all pressure measurement requirements stated in this document.

3.2.3.2.2 Pressure Range

3.2.3.2.2.1 Atmospheric pressure shall be measured or derived and reported when the radiosonde is exposed to all real-world combinations of the environmental conditions specified in Table 2.

3.2.3.2.3 Pressure Measurement Error

3.2.3.2.3.1 The maximum pressure measurement error, after the application of a surface pressure correction, shall not exceed 1.80 hPa, if the pressure is greater than 400.0 hPa and the temperature is between -95ºC and +50ºC for the statistical requirements specified in section 3.2.7.

3.2.3.2.3.2 The maximum pressure measurement error, after the application of a surface pressure correction, shall not exceed 0.60 hPa, if the pressure is between 400.0 hPa and 4.0 hPa and the temperature is between -95ºC and +50ºC for the statistical requirements specified in section 3.2.7.

3.2.3.2.3.3 No more than 5% of all pressure measurements during a flight shall exceed an accuracy of 1.8 hPa at pressure > 400 hPa and 0.5 hPa at pressure from 400 – 4 hPa.

3.2.3.2.3.4 No more than 1% of all pressure measurements during a flight shall exceed an accuracy of 3.6 hPa at pressure > 400 hPa and 1.0 hPa at pressure from 400 – 4 hPa.

3.2.3.2.4 Pressure Functional Precision

3.2.3.2.4.1 The Functional Precision for pressure shall not exceed 0.50 hPa, from Surface to

400 hPa and from 400.0 hPa to 4.0 hPa.

3.2.3.2.5 Pressure Measurement Response Time

3.2.3.2.5.1 The response time over the measurement range for a step change less than or equal to five (5) percent of the initial pressure, shall not exceed 1.0 second.

3.2.3.2.6 Surface Pressure Correction

3.2.3.2.6.1 The radiosonde surface pressure correction shall remove the surface pressure error between the radiosonde and the station precision barometer and bring the pressure measurement to within ± 0.1 hPa of the station’s precision barometer within two attempts to complete the radiosonde baseline procedure.

3.2.3.2.6.2 The radiosonde release point pressure correction from the height of the station

Precision Digital Barometer (PDB) to the height of the release point should be at a resolution of +/- 0.1 hPa and allow corrections up to +/- 5.0 hPa.

3.2.3.3 Temperature Measurement Requirements

3.2.3.3.1 Temperature Range

3.2.3.3.1.1 Atmospheric temperature shall be measured and reported when the radiosonde is exposed to all real-world combinations of environmental conditions specified in Table 2.

3.2.3.3.2 Temperature Measurement Error

3.2.3.3.2.1 The radiosonde temperature error shall not exceed 0.30ºC, at temperatures from -

95.0ºC to +50.0ºC.

3.2.3.3.2.2 No more than 5% of all temperature measurements during a flight shall exceed an accuracy of 0.3ºC.

3.2.3.3.2.3 No more than 1% of all temperature measurements during a flight shall exceed an accuracy of 0.6ºC.

3.2.3.3.3 Temperature Functional Precision

3.2.3.3.3.1 The Functional Precision for temperature shall not exceed 0.30ºC, at temperatures from -95.0ºC to +50.0ºC.

3.2.3.3.4 Temperature Measurement Response Time

3.2.3.3.4.1 The response time shall not exceed 5.8 seconds, at 1013.25 ± 20.00 hPa between -

95.0ºC and +50.0ºC with a ventilation speed between 1.5 m/s and 2.5 m/s.

3.2.3.3.4.2 The response time shall not exceed 3.6 seconds, at 1013.25 ± 20.00 hPa between -

95.0ºC and +50.0ºC with a ventilation speed between 4.5 m/s and 5.0 m/s.

3.2.3.3.5 Temperature Radiation Error

3.2.3.3.5.1 The radiosonde temperature measurement error shall be corrected for the effects of solar and infrared radiation.

3.2.3.3.6 Temperature Sensor Exposure

3.2.3.3.6.1 The primary temperature sensor used to measure the ambient air temperature shall be exposed to the air flow in such a manner that it is not affected by the radiosonde case.

3.2.3.3.6.2 The temperature sensor shall not be located or mounted within an air duct.

3.2.3.4 Relative Humidity (RH) Measurement Requirements

3.2.3.4.1 RH Range

3.2.3.4.1.1 Atmospheric relative humidity shall be measured and reported when the radiosonde is exposed to all real-world combinations of environmental conditions as specified in Table 2.

3.2.3.4.2 RH Sensor Types

3.2.3.4.2.1 Mechanical hygrometers and carbon hygristor sensors are unacceptable.

3.2.3.4.3 RH Measurement Error

3.2.3.4.3.1 The measurement error shall not exceed 5.0 percent relative humidity over the measurement range for temperatures between +50ºC and -60ºC.

3.2.3.4.3.2 The sensor performance shall not degrade as a result of moisture buildup due to condensation or hydrometeor impact as a result of moisture or frost buildup on or near the surface of the humidity sensor.

3.2.3.4.3.3 No more than 5% of all relative humidity measurements during a flight shall exceed an accuracy of 5%.

3.2.3.4.3.4 No more than 1% of all relative humidity measurements during a flight shall exceed an accuracy of 10%.

3.2.3.4.4 RH Functional Precision

3.2.3.4.4.1 The Functional Precision for relative humidity shall not exceed 5.0 percent, at temperatures from +50°C to -60°C.

3.2.3.4.5 RH Measurement Hysteresis

3.2.3.4.5.1 Following exposure to near saturation conditions of 96 +/-2 percent at 25 +/-2ºC, for RH levels below 94 percent, the measurement change due to hysteresis shall not exceed 2 percent RH.

3.2.3.4.5.2 Following exposure to near saturation conditions of 87 +/-2 percent at -10 +/-2ºC, for RH levels below 85 percent, the measurement change due to hysteresis shall not exceed 5 percent RH.

3.2.3.4.5.3 Following exposure to near saturation conditions of 68 +/-2 percent at –35 +/-2ºC, for RH levels below 66 percent, the measurement change due to hysteresis shall not exceed 2 percent RH.

3.2.3.4.6 RH Measurement Response Time

3.2.3.4.6.1 The relative humidity response times, as shown in Table 3 below, at 1013.25 +/-

20 hPa shall not exceed:

Table 3: RH Response Time

Minimum

RH Change*

(percent)

Temp

(ºC)

63 Percent

Time Response

(sec)

90 Percent

Time Response

(sec)

95 Percent

Time Response

(sec)

30 +25.0 +/-2 1.0 3.0 3.4

30 -10.0 +/-2 20.0 60.0 67.4

15 -35.0 +/-2 30.0 90.0 101.1

* The Minimum RH Change represents the minimum step size from the initial to the final conditions within the RH Limits.

3.2.3.4.7 RH Sensor Exposure

3.2.3.4.7.1 The placement of the humidity sensor shall minimize humidity measurement errors caused by; (a) lack of sufficient airflow over the sensor, (b) solar and infrared radiation

(IR) on the humidity sensor, (c) differences between the temperature of the humidity sensor and the temperature used in the humidity calculation, and (d) direct exposure of the humidity sensor to liquid or frozen water.

3.2.3.5 U and V Wind Components Requirements

3.2.3.5.1 The radiosonde and radiosonde ground system shall use data provided by the GPS to calculate the atmospheric wind velocity.

3.2.3.5.2 U and V Wind Components Range

3.2.3.5.2.1 The u and v wind components shall be reported when the radiosonde is exposed to all combinations of environmental conditions specified in section 3.2.2.2.

3.2.3.5.2.2 Wind velocity components, u and v, shall be in the range from -165 m/s to 165 m/s, at a resolution of 0.1 m/s.

3.2.3.5.3 U and V Wind Components Measurement Error

3.2.3.5.3.1 The maximum wind velocity data (smoothed) measurement error shall not exceed

1.0 m/s for the statistical requirements specified in section 3.2.7.

3.2.3.5.4 U and V Wind Components Functional Precision

3.2.3.5.4.1 The Functional Precision for u and v wind components shall not exceed 1.0 m/s.

1.

2.

3.2.3.6 Radiosonde Position Determination Requirements

3.2.3.6.1 The radiosonde shall determine and report the instantaneous radiosonde GPS position and altitude.

3.2.3.6.2 The position data shall not be calculated by integration of velocity measurements over time.

3.2.3.6.3 The altitude reference datum shall be MSL.

3.2.3.6.4 Radiosonde Position Range and Resolution

3.2.3.6.4.1 The horizontal and vertical position measurement ranges shall be reported in latitude, longitude, and altitude to a 250 km slant range and 38 km altitude from the launch site.

3.2.3.6.4.2 The corrected position shall be in hundred thousandths of degrees expressed as

[d]dd.ddddd (degrees, hundred thousandths of degrees).

3.2.3.6.4.3 The reported resolution of the corrected altitude shall be in tenths of meters expressed as aaaaa.a (meters, tenths of meters).

3.2.3.6.5 Radiosonde Position Measurement Error

3.2.3.6.5.1 The maximum horizontal position error shall not exceed 5.0 meters CEP90 and the maximum vertical position error shall not exceed 20.0 meters CEP90 of the received data a during radiosonde flight, in the absence of RF multipath environment and with at least five matching satellites in use.

3.2.3.6.6 Calibration

3.2.3.6.6.1 No calibration, adjustment, or alignment shall be required for thermodynamic data measurements to meet the requirements of this specification.

3.2.4 Radiosonde RF Transmission Requirements

3.2.4.1 Radiosonde Transmission Frequencies

3.2.4.1.1 The radiosonde transmitting frequencies shall be operator selectable in the range of 400.15 to 405.99 MHz.

3.2.4.1.2 The radiosonde transmitting frequency selection shall be configurable to select available channels. The radiosonde shall be tunable to a minimum of 16 individual frequency channels.

3.2.4.2 RF Operation

3.2.4.2.1 RF operation must comply with National Telecommunication and Information

Administration (NTIA) spectrum management policy, allocation, regulations, and technical standards as specified in Chapter 10 of the Manual of Regulations and Procedures for Federal

Radio Frequency Management (Redbook).

3.2.4.3 RF Transmission Inhibit

3.2.4.3.1 Transmission inhibit shall occur if loss of frequency lock occurs, or if the battery voltage drops below the minimum level required to maintain transmitter frequency stability, power output, and nominal spurious response performance.

3.2.4.4 RF Transmitting Antenna

3.2.4.4.1 The radiosonde antenna shall be designed to prevent personal injury during handling and when radiosonde descends after flight termination.

3.2.4.4.2 The radiosonde antenna gain pattern characteristics shall provide reliable radio-link with the radiosonde ground system for the entire flight operation.

3.2.4.5 Radiosonde Self Interference

3.2.4.5.1 The radiosonde RF transmission shall not cause radio interference with any radiosonde component.

3.2.5 Radiosonde Operating Requirements

3.2.5.1 Radiosonde GPS Receiver Requirements

3.2.5.1.1 The radiosonde shall acquire GPS satellite lock prior to launch and retain GPS throughout flight.

3.2.5.2 Train Regulator Requirements

3.2.5.2.1 If a train regulator is included, the train regulator shall be configured to connect the radiosonde to the parachute.

3.2.5.2.2 The train regulator shall deploy 100% cotton (tape, twine, or string) to lower the radiosonde payload at a rate between 0.2 m/s and 0.5 m/s, over the full length of the train regulator's string.

3.2.5.2.3 The tensile strength of the string used must be between 20 and 50 pounds.

3.2.5.2.4 At full deployment, the train regulator shall have a length of 25 to 35 meters of tape, twine or string below the parachute.

3.2.5.2.5 The train regulator size and weight shall be such that FAA Title 14 CFR, Part 101 does not apply.

3.2.6 Radiosonde Preparation and Operating Time Requirements

3.2.6.1 The radiosonde shall meet all performance requirements for preparation, launch, and flight.

3.2.6.2 The total time allowed for radiosonde preparation, 3.2.6.4, warm-up, 3.2.6.5, and launch preparation, 3.2.6.7, shall not exceed 30 minutes.

3.2.6.3 Radiosonde Preparation Area

3.2.6.3.1 Prior to unpacking, the radiosonde shall be placed in a preparation area for a minimum of 1.0 hour in the conditions identified in Table 2.

3.2.6.3.2 Radiosonde movements during transportation from the radiosonde preparation area to the launch location shall not degrade the performance of the radiosonde ground system.

3.2.6.4 Radiosonde Preparation

3.2.6.4.1 The amount of time that one operator must devote to preparing the radiosonde shall not exceed 15 consecutive minutes, including the time required for battery preparation and warm up.

3.2.6.5 Warm Up

3.2.6.5.1 The warm up interval shall comprise of the period of time between the radiosonde being powered on and the radiosonde transmitting data that meets this specification.

3.2.6.6 Full Specification Performance Time Interval

3.2.6.6.1 The radiosonde shall meet all performance requirements under battery power for a minimum of 135 minutes after radiosonde preparation.

3.2.6.7 Launch Preparation

3.2.6.7.1 The interval between the end of the warm up period and launch will not exceed 15 minutes.

3.2.6.7.2 The time for the radiosonde to download GPS ephemeris data, and acquire minimum satellite lock shall occur during the 15 minute interval between the end of warm up and launch, and not require more than 3.0 minutes.

3.2.6.7.3 The radiosonde shall provide an indication that the radiosonde is ready for launch.

3.2.7 Statistical Requirements for Radiosonde Observations

3.2.7.1 A minimum of 96.0 percent of all radiosondes shall meet all performance requirements of 3.2 and shall not lose more than a total of 4.0 minutes of meteorological data during a 135-minute flight rising at a rate of 300 +50 meters per minute to a slant range of

250 +1 km.

3.2.7.2 For flights of less than 120.0 minutes due to balloon burst or excess range, the allowable total data loss shall be the ratio of the actual flight time in minutes divided by 135, multiplied by the maximum allowable meteorological data loss specified herein.

Example: A 100 minute flight terminated due to balloon burst shall not lose more than

11.1 seconds of pressure, temperature and humidity data per 5 minutes of flight time.

(100/135)*15 seconds = 11.1 seconds.

3.2.7.3 A minimum of 99.0 percent of all radiosondes shall meet the measurement requirements of 3.2.3 and shall not lose more than 15 seconds of pressure, temperature, and humidity data per 5 minutes of flight time during a 135-minute flight rising at a rate of 300

+50 meters per minute to a slant range of 250 +1 km.

3.2.7.4 These requirements shall be met with a maximum customer risk of 1.0 percent for the RF transmission requirements in section 3.2.4 and 2.0 percent for the remaining specification requirements.

3.2.7.5 All radiosonde failures beyond the failures allowed for customer risk shall be dealt with, in accordance with the warranty provisions in the contract.

3.3 Physical Characteristics

3.3.1 Radiosonde Weight/Size Ratio

3.3.1.1 The radiosonde size and weight shall be such that FAA Title 14 CFR, Part 101 does not apply.

3.3.2 Radiosonde Design

3.3.2.1 The design shall prevent sensor contamination and solar and infrared (IR) effect on radiosonde sensor measurements and prevent damage to equipment and environment.

3.3.2.2 The radiosonde design shall prevent water from entering the compartments housing the electronic components under flight conditions in Table 2.

3.3.2.3 Meteorological Sensors

3.3.2.3.1 The physical design of the radiosonde shall be such that its sensors will not be damaged during shipping, preparation for flight, ground handling, release, and flight.

3.3.2.4 Radiosonde Sensor Coating

3.3.2.4.1 All sensor coatings shall be applied in a consistent and uniform manner, both sensor-to-sensor and lot-to-lot.

3.3.2.5 Radiosonde Case and Sleeve

3.3.2.5.1 The radiosonde case and sleeve shall be made of non-hygroscopic, non-biodegradable materials that do not absorb moisture in the environment conditions in Table

2.

3.3.2.5.2 The materials shall be rigid and strong enough to withstand normal handling on the ground before release and the stresses of a flight.

3.3.2.5.3 There shall be no sharp edges, corners, nor protrusions that could cause personal injury.

3.3.2.5.4 The color of the sleeve or case (if no sleeve is provided) shall be such that solar/IR effects on the sensors are minimized.

3.3.2.5.5 The case shall be designed to prevent any adverse RF effects during radiosonde baseline preparation, ground handling, and at release and immediately thereafter.

3.3.2.6 Waterproofing

3.3.2.6.1 The case shall be so designed, constructed and assembled such that water will not enter the compartments housing the electronic components under any flight conditions.

3.3.2.6.2 Waterproof sealant shall be applied at all points where wires feed through the case and at any other potential moisture intrusion points. All surfaces, supports, and connections shall be so constructed and treated such that liquid, frozen or any combination of precipitation on the radiosonde will not cause performance degradation.

3.3.3 Radiosonde Serial Number

3.3.3.1 A serial number shall be securely applied to the circuit board and to the outside of the casing.

3.3.3.2 The serial number shall consist of not more than 12 characters (numerals and letters). The format of the serial number shall be established by mutual agreement between the Government and the Vendor.

3.3.3.3 All lettering shall be permanent and impervious to liquid and moisture (i.e.

weatherproof) and be readable for at least 6 months when exposed to operational conditions listed in Table 2.

3.3.4 Battery Compartment

3.3.4.1 The battery compartment shall be designed to prevent leakage of battery electrolyte from the battery compartment to the exterior of the radiosonde and of gases onto any of the radiosonde electronics or sensors during preparation, installation, flight, and on the ground after flight termination.

3.3.5 Lifting Device

3.3.5.1 There shall be a lifting device attached to the top of the case or sleeve over the center-of-gravity of the radiosonde when prepared for flight.

3.3.5.2 The lifting device shall be designed for convenient attachment of the balloon flight train.

3.3.5.3 Neither the lifting device nor any component of the radiosonde shall be damaged by pulling on the lifting device.

3.3.6 Nameplate, Labeling, and Product Marking

3.3.6.1 Radiosonde Labels

3.3.6.1.1 For the purpose of this specification, the term “label” shall denote text and/or symbols on the contrasting radiosonde sleeve or case.

3.3.6.1.2 The text and/or symbols shall be of such contrast to be easily legible in low light conditions.

3.3.6.1.3 The process by which a label adheres to the radiosonde sleeve or case shall have prior written Government approval.

3.3.6.1.4 The labels shall remain affixed to the radiosonde and be clearly legible when exposed to conditions identified in section 3.2.2.2 for at least six months.

3.3.6.2 Harmless Labels

3.3.6.2.1 The radiosonde shall have a Harmless Label as shown in Figure 1, on three different sides of the radiosonde.

3.3.6.2.2 At least one Harmless Label shall be visible, when the radiosonde is lying on any of its sides.

3.3.6.2.3 The label shall be weatherproof and be readable for at least 6 months when exposed to operational conditions listed in 3.2.2.2.

3.3.6.2.4 The label shall also use the largest, legible and high contrast Arial font the side will permit without impacting the radiosonde performance.

3.3.6.2.5 One of the sides with a Harmless Label shall also include the label shown in

Figure 2.

HARMLESS WEATHER INSTRUMENT

www.weather.gov/upperair/radiosonde

Figure 1 - Harmless Weather Instrument Label

This is a radiosonde, a balloon-borne instrument used by the NOAA National Weather Service (NWS) to obtain data aloft for weather forecasts and research. IT IS NOT DANGEROUS. Please do not return the radiosonde to the NWS. Recycle or dispose of properly.

Figure 2 – Additional Harmless Label http://www.weather.gov/upperair/radiosonde

3.3.6.3 NOAA Symbol Label.

3.3.6.3.1 The radiosonde shall have at least one (1) NOAA Symbol Label shown in Figure

3.

3.3.6.3.2 The NOAA Symbol shall have a height not less than 2.5 cm and can be monochromatic.

3.3.6.3.3 The NOAA symbol shall be located on the radiosonde side opposite of the temperature sensor.

Figure 3 - NOAA Symbol

4.0 GOVERNMENT ACCEPTANCE

4.1 The Government will verify the radiosondes perform in accordance to this specification.

4.2 The Government Acceptance will consist of visual inspections, comparison against established references, and live flight tests including: in-situ flights; functional comparison and functional precision flights.

4.3 The Government shall notify the Contractor of defects or deficiencies against the specification requirements in accordance with the provisions in the contract.

5.0 PREPARATION FOR DELIVERY

5.1 Preparation for Packaging

5.1.1 Radiosonde Packaging

5.1.1.1 Radiosondes shall be individually prepared for packaging.

5.1.1.2 All outboard structures shall be stored in the self-contained storage areas in the radiosonde.

5.1.1.3 Radiosonde packaging shall ensure safe and undamaged delivery to their destination.

5.1.1.4 Immediately after acceptance of the radiosondes by the Government inspector, the radiosondes shall be packed in corrugated shipping cartons.

5.1.1.5 All components and accessories furnished by the Vendor (including calibration data, in hard and soft format, if not already loaded in the radiosonde) for each radiosonde shall be packed in the same carton as the radiosondes.

5.1.1.6 The maximum weight shall not exceed 34 kg, and the girth plus length shall not exceed 2.75 m, in accordance with U.S. postal regulations.

5.1.2 Packaging

5.1.2.1 Each carton shall be labeled with National Weather Service nomenclature, type number, manufacturer’s name, date of manufacture, serial numbers, shipment number, and number of boxes in the shipment (e.g., 1 of 6).

5.1.2.2 The Vendor shall furnish a packing list with each shipment of radiosondes to a destination.

5.1.2.3 The entries to be shown on the packing list will be specified by the Contracting

Officer prior to the first shipment.

5.1.2.4 A copy of instructions for preparing the radiosonde and battery for flight shall be included in each radiosonde shipping box.

5.1.3 Sensor Packaging

5.1.3.1 The humidity sensors (or radiosonde if the humidity sensor is permanently attached) shall be supplied in individual hermetically sealed containers for transportation and storage which shall prevent contamination of any kind.

5.1.3.2 Sufficient desiccant shall be packed in each sealed container to prevent condensation of entrapped water vapor at low temperature.

5.1.3.3 The desiccant shall be packed in a sturdy, spill-proof, package and shall not contaminate any part of the radiosonde.

5.1.3.4 The humidity sensor shall be packaged in a manner that shall prevent damage to the sensor during transportation and storage.

5.1.3.5 For shipment, the humidity sensor container shall be placed inside the radiosonde compartment where practical; otherwise, it shall be packed in the radiosonde shipping carton.

2. Acronyms

1.

Acronym Definition

CEP Circular Error Probable

CFR Code of Federal Regulations

FAA Federal Aviation Administration

GNSS Global Navigation Satellite System

GPS Global Positioning System hPa Hectopascal

IR Infrared radiation

NOAA National Oceanic and Atmospheric Administration

NTIA National Telecommunications and Information Administration

NWS National Weather Service

PDB Precision Digital Barometer

RF Radio Frequency

RH Relative Humidity

2.

3. Glossary

CEP - Circular Error Probability: GPS accuracies specified as CEP refer only to the horizontal plane, i.e. position on a map. CEP is defined as the radius of a circle centered on the true value that contains 90% of the actual GPS measurements.

Explanation: https://en.wikipedia.org/wiki/Circular_error_probable

Functional precision tests are conducted to determine the amount of measurement variability that exists between two identical instruments (the two instruments are simultaneously exposed to the same environment). To determine the functional precision, the root mean square of the differences (MSD) is calculated for each parameter.

Hysteresis is the time-based dependence of a system’s output based on present and past inputs.

https://en.wikipedia.org/wiki/Circular_error_probable