MROS SPECIFICATION - P20001.docx

SPECIFICATION

FOR

National Weather Service (NWS)

RADIOSONDE OBSERVATION SYSTEM

(Acquisition Sensitive)

May 1, 2020

DEPARTMENT OF COMMERCE

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL WEATHER SERVICE

OFFICE OF OBSERVATIONS

1325 EAST WEST HIGHWAY

SILVER SPRING, MD 20910

NWS-J100-ROS-SW001

Revision - C

This document contains proprietary or source selection information related to the conduct of Federal agency procurement. The disclosure and receipt of this information is restricted by Section 27 of the Office of Federal Procurement Policy Act (41 U.S.C. 423). The unauthorized disclosure of this information may subject both the discloser and the recipient to the contractual, civil, and/or criminal penalties as provided by law.

1.0 SCOPE

This specification defines the requirements for the National Weather Service (NWS) radiosonde observation software 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

Copies of the National Weather Service Manual 10-1401 are available from the NWS Upper Air Observations Program at https://www.weather.gov/upperair/.

2.2 Non-Government Documents

Manual on Codes

International Codes, Part A- Alphanumeric Codes, WMO-No.306, FM 35-XI Ext. TEMP

International Codes, Part B-Binary Codes, WMO-No.306, FM 94-XIV BUFR

Copies of WMO documents are available from http://www.wmo.int.

3.0 REQUIREMENTS

General This specification defines the requirements for the NWS radiosonde observation system including radiosonde, tracking system and observation software. Whenever a specific paragraph of this specification is referenced, all subparagraphs of the referenced paragraph also apply. The usage of the term “shall” implies a mandatory requirement, whereas the usage of the terms “preferred” implies a non-mandatory requirement.

Radiosonde Description The radiosonde is a lightweight all-weather instrument. The radiosonde measures or derives atmospheric pressure, temperature, relative humidity (RH), wind speed & 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 position. The radiosonde transmits these thermodynamic and position measurements via a 403MHz transmitter and antenna to the Radiosonde Tracking System (RTS) for data processing.

Radiosonde Tracking System Description The Radiosonde Tracking System (RTS), hereafter referred to as the tracking system, function is to receive, process the radiosonde telemetry into meteorological data and transmit meteorological products to the Observation Software.

Radiosonde Observation Software The Radiosonde Observation Software (ROS), hereafter referred to as the observation software, receives and processes radiosonde data from preflight to termination. ROS provides data quality control and encodes and transmits meteorological products via connected data pathways. The ROS performs system initialization and diagnostics, communicates with peripheral devices, processes meteorological data, monitors ground system performance, and disseminates data products. The ROS allows user interaction with data displays, data products, data dissemination, and radiosonde tracking system. The ROS displays and allows the modification of system information and station parameter information.

3.1 RADIOSONDE REQUIREMENTS

Radiosonde Design

3.1.1 The radiosonde shall be calibrated prior to delivery to the Government.

3.1.2 The radiosonde shall process telemetry data at a continuous rate of 2.0 seconds or faster.

3.1.3 The radiosonde battery shall provide a minimum of 135 minutes of power after radiosonde preparation.

3.1.4 The radiosonde design shall prevent early termination and performance degradation from moisture penetration under flight conditions.

3.1.5 T

he radiosonde sensors shall perform consistently from radiosonde-to-radiosonde and lot-to-lot. The preferred radiosondes have sensor coatings applied in a consistent and uniform manner, both sensor-to-sensor and lot-to-lot.

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

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

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

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

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

Radiosonde Packaging Requirements

3.1.11 The radiosonde packaging shall maintain the integrity and safety of the radiosonde throughout the life of transport and circulation throughout the inventory system, so that at its ultimate destination the radiosonde is operationally functional and undamaged. Each carton/case and outer containers shall contain a bar-coded label containing the Agency Stock Number (ASN) and National Stock Number (NSN) numbers for a radiosonde box of 40.

3.1.12 Each carton/case and outer containers shall also be labeled with contract number, manufacturer’s name, date of manufacture, and serial numbers, for example see Figure 1.

Figure 1 – Packing Label

3.1.13 A packing list shall be provided with each shipment of radiosondes to a destination.

3.1.14 The entries to be shown on the packing list shall be specified by the Contracting Officer prior to the first shipment.

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

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

3.1.17 A serial number shall be securely applied to the circuit board and to the outside of the casing for easy viewing by the operator.

3.1.18 The serial number shall consist of not more than 12 characters (numerals and letters).

3.1.19 The preferred format of the serial number is YYJJJ-XXXXXX, with YY - calendar year, JJJ - Julian Date (1-366), and XXXXXX - sequential ID# (000001 to 999999).

3.1.20 All lettering shall be permanent and impervious to liquid and moisture (i.e. weatherproof). The preferred lettering remains readable for at least 6 months when exposed to operational conditions.

3.1.21 The battery compartment shall be designed to prevent leakage 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.

Lifting Device

3.1.22 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.

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

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

Radiosonde Labels

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

3.1.26 The labels shall remain affixed to the radiosonde sleeve or case for at least 6 months.

3.1.27 The labels shall be clearly legible. The preferred labels remain legible when exposed to outdoor environmental conditions for at least six months.

3.1.28 The radiosonde shall have a Harmless Label as shown in Figure 2.

3.1.29 The Harmless Label shall be on three different sides of the radiosonde or as negotiated with the Government.

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

3.1.31 One of the sides with a Harmless Label shall also include the label shown in Figure 3.

3.1.32 The radiosonde shall have at least one NOAA Symbol Label shown in Figure 4.

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

3.1.34 The NOAA symbol shall be located on the radiosonde side opposite of the temperature sensor or as negotiated with the Government.

Mailing Bag - Only for Vendors offering radiosonde reconditioning services.

3.1.35 A folded, plastic self-sealing mailbag shall be attached to each radiosonde to allow recovery and return of the instrument to the Government.

3.1.36 The mailbag shall have a postage-paid address, provided by the Government, printed on it.

3.1.37 One of the sides with a Harmless Label shall include the label shown in Figure 5.

Figure 5 - Mailing Bag Label

Radiofrequency Requirements

3.1.38 The radiosonde transmitting frequencies shall be in the range of 400.15 to 405.99 MHz.

3.1.39 The radiosonde shall be tunable to a minimum of 16 individual frequency channels.

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

3.1.41 Radiosonde operation shall 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).

General Measurement Requirements

3.1.42 The requirements specified herein are applicable to all measurements.

3.1.43 Atmospheric measurements shall meet all accuracy measurement error requirements and be reported when the radiosonde is exposed to all real-world combinations of environmental conditions.

3.1.44 The radiosonde shall have no more than 3 % data loss over the duration of the flight.

3.1.45 The radiosonde shall meet the atmospheric thermodynamic measurement requirements with a ventilation rate of 4-6 m/s from surface to termination.

3.1.46 No more than 1% of a sounding shall have a temperature cooling lapse rate exceeding -1.5 ˚C per 50 m to minimize perturbations to air temperature measurements from wetting, icing and condensation.

Pressure Measurement Requirements

3.1.47 The required pressure accuracy measurement error is 1.8 hPa, from surface to 100 hPa.

3.1.48 The required pressure accuracy measurement error is 0.6 hPa, from 100 hPa to 10 hPa.

Temperature Measurement Requirements

3.1.49 The required radiosonde temperature measurement erroraccuracy is 0.5 °C from surface to 100 hPa.

3.1.50 The required radiosonde temperature measurement erroraccuracy is 1.0 °C from 100 to 10 hPa.

Relative Humidity Measurement Requirements The radiosonde humidity measurement erroraccuracy is 5 percent in the troposphere.

Mechanical hygrometers and carbon hygristor sensors shall not be utilized.

Wind Measurement Requirements

3.1.51 The radiosonde and radiosonde tracking system shall use data provided by the GPS to calculate the atmospheric wind measurement. The preferred radiosonde acquires GPS satellite lock prior to launch and retains GPS throughout flight.

Wind Direction Measurement Requirements

3.1.52 The radiosonde wind direction error shall not exceed 5.0° from surface to 100 hPa and < 15 m/s.

3.1.53 The radiosonde wind direction error shall not exceed 2.5° from surface to 100 hPa and > 15 m/s.

3.1.54 The radiosonde wind direction error shall not exceed 5.0° from surface to 100 to 10 hPa.

Wind Speed Measurement Requirements

3.1.55 The radiosonde wind speed error shall not exceed 1 m/s from surface to 100 hPa.

3.1.56 The radiosonde wind speed error shall not exceed 2 m/s from 100 to 10 hPa.

Position Measurement Requirements

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

3.1.58 The radiosonde altitude reference datum shall be Mean Sea Level (MSL).

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

3.1.60 The maximum horizontal position error shall not exceed 5.0 meters Circular Error Probability (CEP) 90 and the maximum vertical position error shall not exceed 20.0 meters CEP 90of the received data during radiosonde flight, in the absence of radio frequency (RF) multipath environment and with at least 5 matching satellites in use. radiosonde altitude error shall not exceed 1 percent near the surface decreasing to 0.5 percent at 100 hPa.

Radiosonde Performance Requirements

3.1.61 The time for the radiosonde to download GPS ephemeris data and acquire minimum satellite lock shall not require more than 5.0 minutes during preparation.

3.1.62 The radiosonde shall have no more than 3 % data loss over the duration of the flight.

3.1.63 The radiosonde shall not lose more than 5 % of pressure, temperature, humidity, radiosonde velocity, radiosonde position, and wind velocity data per 5 minutes of flight time during the duration of the flight.

3.1.64 Radiosonde preparation shall not degrade radiosonde performance.

3.1.65 Preparation of the radiosonde shall not exceed 15 minutes.

Radiosonde Documentation

3.1.66 The radiosonde documentation shall provide storage, preparation and operation instructions.

3.2 RADIOSONDE TRACKING SYSTEM

3.2.1 The tracking system shall have a minimum service availability of 99.0%.

3.2.2 The tracking system shall provide a Universal Serial Bus (USB) or Ethernet interface to the sounding workstation.

3.2.3 The tracking system shall synchronize the internal clock with the sounding workstation.

3.2.4 The tracking system shall report system status to the sounding workstation continuously.

3.2.5 The tracking system shall track the radiosonde to a minimum slant range of 250 km radius from the launch point.

3.2.6 The tracking system shall track the radiosonde to an atmospheric pressure level of 4 hPa (approximately 37,500 km MSL).

3.2.7 The tracking system shall output meteorological data at a continuous rate of 2.0 seconds or faster to the radiosonde observation software.

3.2.8 The time elapsed between the time of measurement of thermodynamic data until the time that data is presented to the operator shall not exceed 60 seconds.

3.2.9 The tracking system shall provide the radiosonde frequency, signal strength, and GPS status to the sounding workstation in real-time.

3.2.10 The tracking system shall provide raw and meteorological data to the sounding workstation.

Radiosonde Tracking System Documentation

3.2.11 The radiosonde Tracking System documentation shall provide installation, preparation, maintenance and operation instructions.

Radiosonde Tracking System Electric Power Requirements

3.2.12 All electrical power circuits, electrical power components, and wiring inside the tracking system shall comply with the 2017 edition of the National Fire Protection Association Code Number 70, National Electric Code (NFPA70: NEC 2017) and the 2017 NESC.

3.2.13 All AC electrical power wiring shall use United States wire color-coding in conformance with NFPA70: NEC 2017.

3.2.14 Primary power to the tracking system shall be single phase 120V/240V, 60 Hertz.

3.2.15 All AC electrical power plugs shall be North American types and conform to the American National Standards Institute/National Electrical Manufacturers Association Standard WD-6 (ANSI/NEMA WD-6).

3.3 RADIOSONDE OBSERVATION SOFTWARE

3.3.1 The Radiosonde Observation Software shall operate on Windows (Microsoft Windows 10 or newer).

3.3.2 The Radiosonde Observation Software shall allow for modification or upgrade by installation of new sounding software, Operating System and firmware on a monthly basis.

Preflight

3.3.3 After initializing, the Radiosonde Observation Software shall automatically set the internal clock to Coordinated Universal Time (UTC) time.

3.3.4 The Radiosonde Observation Software shall perform a scan of the 400.15-405.99 MHz bandwidth to display and identify available frequencies.

3.3.5 The Radiosonde Observation Software shall verify the radiosonde is performing within the manufacture tolerances preflight.

3.3.6 The Radiosonde Observation Software shall display pressure, temperature, and relative humidity (PTU) data and latitude/longitude during baselining.

Software / Tracking System Interface

3.3.7 The Radiosonde Observation Software shall communicate with and interface with the tracking system.

3.3.8 The Radiosonde Observation Software shall include the ability to manually control the ground system to conduct a radiosonde observation.

3.3.9 The Radiosonde Observation Software shall allow the operator to set the tracking system frequency.

3.3.10 The Radiosonde Observation Software shall store and display radiosonde frequency and signal strength, elevation angle, and Global Positioning System (GPS) data (status and count) to the user in real-time. The preferred software also stores and displays radiosonde slant range and GPS data (signal-to-noise ratio) to the user in real-time.

3.3.11 The Radiosonde Observation Software system shall timestamp observation data based on the sounding workstation and/or GPS time.

3.3.12 The Radiosonde Observation Software shall record pre-flight information as identified in Table 1, prior to flight.

Table – 1 Preflight Parameters Surface Observations

3.3.13 The Radiosonde Observation Software shall make use of as many of the surface observation information as possible, identified in Table 2, from the surface weather equipment.

Table – 2 Surface Observation Parameters

3.3.14 The Radiosonde Observation Software shall calculate and display the surface dewpoint temperature from entered surface RH or Wet bulb data if a dew point measurement is not available.

3.3.15 When applied the radiosonde release point pressure correction from the height of the station’s PDB to the height of the release point shall be at a resolution of 0.01 hPa and allow corrections up to ± 5.0 hPa.

3.3.16 The Radiosonde Observation Software shall allow for communication with surface sensors for use of surface observation data.

3.3.17 The Radiosonde Observation Software shall allow for manual entry of surface observation data. The preferred Radiosonde Observation Software auto-populates surface observation data.

3.3.18 If the surface observation data is modified during a flight, the Radiosonde Observation Software shall reprocess the sounding data.

Launch/Release Detection

3.3.19 The Radiosonde Observation Software shall detect radiosonde launch and report with time (in UTC) with an accuracy of 2 seconds or faster.

3.3.20 The Radiosonde Observation Software shall provide the capability to change the launch detection time.

3.3.21 If the launch detection time is modified, the Radiosonde Observation Software shall recalculate the processed data based on the new launch time.

3.3.22 The Radiosonde Observation Software shall support (and prompt the user for) a second or third release of the same ascension number and observation time, following an unsuccessful sounding.

3.3.23 The release window for synoptic observations (00:00, 06:00, 18:00, and 12:00 UTC) shall be 60 minutes before to 29 minutes after the assigned observation time.

3.3.24 The release window for non-synoptic observations shall be 30 minutes before to 29 minutes after the assigned observation time.

3.3.25 For synoptic observations, if the release occurs early, even one second before the release time window, the Radiosonde Observation Software shall log the flight as a 23:00, 05:00, 17:00, or 11:00 UTC observation, respectively.

3.3.26 For synoptic observations, if the release occurs late, even one second beyond the release time window, the Radiosonde Observation Software shall log the flight as a 01:00, 07:00, 19:00, or 13:00 UTC observation, respectively.

Flight

3.3.27 The Radiosonde Observation Software shall determine when a sounding is successful, based on (1) the temperature being present for 3.0 minutes of the first 5.0 minutes of the flight, (2) the pressure decreasing by at least 5 hPa during the first 5.0 minutes of the flight, and (3) the flight reaching 400 hPa before terminating.

3.3.28 The Radiosonde Observation Software shall have the capability to abort processing prior to balloon release.

3.3.29 The Radiosonde Observation Software shall receive, display and store meteorological parameters, as identified in Table 3, from the tracking system.

Table - 3 Meteorological Parameters

3.3.30 The Radiosonde Observation Software shall allow the entry and modification of the site-specific information, as identified in Table 4, for the generation of Upper Air data products.

Table – 4 Site Specific Information

3.3.31 All measurements shall have the same resolution or greater as the corresponding measurement error. For example, if the pressure data measurement error has a resolution of one decimal place (e.g. 0.06 hPa), then the resolution of the pressure measurement errorpressure data should be have a resolution of at least one decimal place (e.g. 0.06 hPa).

3.3.32 The Radiosonde Observation Software shall perform quality control to determine valid data, for the parameters identified in Table 5.

Table – 5 Quality Control

3.3.33 The Radiosonde Observation Software shall terminate a flight automatically when the radiosonde data indicates excessive missing data in accordance with the criteria listed in Table 6.

Table – 6 Missing Data

Data Display

3.3.34 The Radiosonde Observation Software shall provide the user the ability to display the Upper Air data products during the flight.

3.3.35 The Radiosonde Observation Software shall display the radiosonde observation data in tables, including as a minimum, raw PTU tabular, processed tabular, WMO products (FZL, MAN, SGL, ABV), and BUFR.

3.3.36 The Radiosonde Observation Software shall display, at a minimum, processed data in plots, Skew-T (surface to 100 hPa), Stuve (surface to 5 hPa), and vertical profile plots of temperature, dewpoint, relative humidity, pressure and winds with respect to flight time.

3.3.37 The Radiosonde Observation Software shall display vertical profile plots of temperature, dewpoint, relative humidity, pressure and winds. The preferred software displays data in the plots from five minutes before balloon launch to one minute after flight termination. The preferred software also allows the user to pan and zoom plots.

3.3.38 Throughout the radiosonde observation, the Radiosonde Observation Software shall allow the operator to flag the highest resolution (e.g. 1 or 2 second) processed tabular and/or graphical observation data to eliminate the data from being displayed or used in the development of Upper Air data products.

3.3.39 The Radiosonde Observation Software shall allow the operator to un-flag the high resolution (e.g. 1 or 2 second) processed tabular and/or graphical observation data to restore the original data for display and use in the development of Upper Air data products.

3.3.40 When less than one minute of the high resolution (e.g. 1 or 2 second) processed tabular and/or graphical observation data is flagged, the Radiosonde Observation Software shall interpolate high resolution (e.g. 1 or 2 second) data to replace the flagged data.

3.3.41 When 1 minute or more of the high resolution (e.g. 1 or 2 second) processed tabular and/or graphical observation data is flagged, the Radiosonde Observation Software shall eliminate the data from being displayed and used in the development of Upper Air data products.

3.3.42 The Radiosonde Observation Software shall allow the capability to export the time-stamped tabular data from each radiosonde observation as Comma Separated Values (CSV) text files.

Binary Universal Form for data Representation (BUFR) Requirements

3.3.43 The Radiosonde Observation Software shall generate the sounding data into a BUFR (3-09-52) message in accordance with the WMO Manual on Codes (WMO-No. 306), FM 94 for both Regions IV and V. Note: For sites in Region V apply the low-level winds and stability index as specified for region IV.

3.3.44 The BUFR (3-09-52) message shall be formatted in accordance with the WMO Manual on Codes (WMO-No. 306), Volume I.2 Part C, Regulation B/C25.

3.3.45 The Radiosonde Observation Software shall automatically disseminate the BUFR messages in accordance with Table 19.

3.3.46 The Radiosonde Observation Software shall save the Upper Air Data Products locally as a text file(s) for BUFR Messages.

WMO Coded Messages Requirements

3.3.47 The Radiosonde Observation Software shall generate the sounding data into a WMO Coded Message in accordance with the WMO Manual on Codes (WMO-No. 306), FM 35 for both Regions IV and V. Note: For sites in Region V apply the low-level winds and stability index as specified for region IV.

3.3.48 The Radiosonde Observation Software shall code heights appearing in the WMO coded messages using units of geopotential meters.

3.3.49 The Radiosonde Observation Software shall select a temperature level as significant and include in the TTBB if the Greatest Departure of Linearity exceeds ± 0.5 °C for pressures from surface to 100 hPa.

3.3.50 The Radiosonde Observation Software shall select a temperature level as significant and include in the TTDD if the Greatest Departure of Linearity exceeds ± 1.0 °C for pressures from 100 hPa to termination.

3.3.51 The Radiosonde Observation Software shall select a Relative Humidity level as significant and include in either the TTBB or TTDD (depending on the pressure at that level) if the Greatest Departure of Linearity exceeds ± 5 % for all pressures.

3.3.52 The Radiosonde Observation Software shall automatically disseminate the WMO Coded message in accordance with Table 9.

3.3.53 The Radiosonde Observation Software shall save the Upper Air Data Products locally as a text file(s) for WMO Coded Messages.

Radiosonde Additional Data (RADAT)

3.3.54 The Radiosonde Observation Software shall generate the sounding data into a RADAT message as described in Appendix B - RADAT.

3.3.55 The Radiosonde Observation Software shall automatically disseminate the RADAT message in accordance with Table 19.

Message / Product Dissemination

3.3.56 The first level data in the WMO coded messages and Archive Product shall be the surface observation information listed in Table 2. The preferred Radiosonde Observation Software saves each sounding data product as a file for disseminating sounding data via e-mail.

3.3.57 The Radiosonde Observation Software shall have visual and audible indications when messages have been generated.

3.3.58 In the event of a failed dissemination of the Upper Air data products, the Radiosonde Observation Software shall allow for automatic or manual retransmission.

3.3.59 The Radiosonde Observation Software shall provide the capability to generate and disseminate Upper Air data products as directed by the user.

3.3.60 The Radiosonde Observation Software shall apply the UTC date and time to all transmitted messages.

3.3.61 The Radiosonde Observation Software shall have the ability to retransmit Upper Air data products for up to 6 hours from the time a release was detected.

3.3.62 The Radiosonde Observation Software shall be configurable to automatically and manually disseminate messages and products through a Secure Shell (SSH) File Transfer Protocol (SFTP) via LAN and/or modem connections.

3.3.63 The SFTP connection shall be compatible with Federal Information Processing Standards (FIPS) Publication 140-2 compliance Crypto Keys as outlined in security control SC-12 of the Recommended Security Controls for Federal Information Systems found in Appendix E.

3.3.64 In the event of premature termination, the Radiosonde Observation Software shall generate and disseminate Upper Air products up to the termination level.

3.3.65 The Radiosonde Observation Software shall allow a user to generate and disseminate a No Data Message as described in Appendix A in the event where a sounding cannot be conducted.

3.3.66 The Radiosonde Observation Software shall keep track of the number of times WMO coded messages have been transmitted (manually or automatically). (Note: In the event the messages are transmitted more than once, the header shall be modified to reflect the number of re-transmits. This modification shall be an automatically generated incremental number utilizing the last two digits in the date and time parameter of the header. Also appended to the end of the header, a ‘COR’ shall be added).

3.3.67 The Radiosonde Observation Software shall allow the entry and modification of LDAD data dissemination parameters, as identified in Table 7, used for message transmission.

Table 7 - LDAD parameters Post Flight

3.3.68 All radiosonde observation data shall be a discrete, incrementally time-stamped value representing the measured radiosonde data from a single non-overlapping radiosonde-sampling period.

3.3.69 The Radiosonde Observation Software shall save all sounding data accessible for analysis (e.g., telemetry, raw, processed, etc.).

3.3.70 The Radiosonde Observation Software shall automatically detect and assign a flight termination reason to each flight as specified in Appendix A.

3.3.71 The Radiosonde Observation Software shall allow a user to modify the flight termination reason after the process has completed.

The Radiosonde Observation Software shall locally save logs pertaining to the system status, antenna status and software debugger as text files. The preferred software automatically uploads all sounding data to a configurable SFTP address for off-site analysis.

3.3.72 The Radiosonde Observation Software shall capture and retain the asterisked (*) elements in Pre-Flight information (Table 8A), Flight information (Table 8B), and Flight Data Interval information (Table 8C) in a flight summary report. The preferred software allows retrieval of all Pre-Flight, Flight information and Flight Data Interval Information parameters to be summarized in the flight summary report.

3.3.73 The Radiosonde Observation Software shall have the ability to reopen flight data from previous soundings/flights. The preferred software ability is to re-run and re-process previous soundings as simulated soundings/flights.

3.3.74 The Radiosonde Observation Software shall allow a configurable file name structure to include site ID, release number, ascension number, and message type (e.g., BUFR, RADAT, Mandatory and Significant Levels).

Operator Initials (minimum of 3 characters)

(-20 C Height) Max Wind [Level, Elapsed Time (min), Height (m), Pressure (hPa), Temperature (C)]

Mean Low Level Wind

· Surface to 5000 feet

· 5000 to 10,000 feet Tropopause Levels [Level, Elapsed Time (min), Height (m), Pressure (hPa), Temperature (C)] Radiosonde Ascent Rate Averages

· Surface to 400 hPa

· 400 hPa to Termination

· Surface to Termination

· Surface to 100 hPa

· 100 hPa to Termination

· Raw Pressure / Height

· Raw Temperature

· Raw Relative Humidity

· Raw Wind Data

Archive Data Product

3.3.75 The Radiosonde Observation Software shall generate the sounding data into an Archive Product as described in Appendix D - Archive Product.

3.3.76 The Radiosonde Observation Software shall code heights appearing in the Archive Product using units of measure declared in documentation and/or header file. The preferred unit is geopotential meters

3.3.77 The Radiosonde Observation Software shall include the H, T, and B files in a compressed file (e.g. *.zip) named as indicated below. The formatting of the individual H, T, and B files are described in Appendix D.

XXXXDDMMYYHH.zipXXXXDDMMYYYY.zip

· XXXX is the Station ID

· YY = Year

· MM = Month

· DD = Day of Month

· HH = Hour

· Example: kmpx16101700.zip

3.3.78 The Radiosonde Observation Software shall provide the capability to disseminate on a flight by flight basis the H, T, B (3-09-06x), and C (3-09-052) files in a compressed file (e.g. *.zip) named as indicated below.

3.3.79 The Radiosonde Observation Software shall provide the capability to disseminate on a monthly basis the H, T, B (3-09-6x), and C (3-09-52) files in a compressed file (e.g. *.zip) named as indicated below.

3.3.80 The Radiosonde Observation Software shall format the individual H, T, and B (3-09-6x) files as described in Appendix D.

3.3.81 The Radiosonde Observation Software shall disseminate to NCEI the compressed Archive Product in accordance with Table 9.

and FMH3 Appendix E. Table 0421

Archive Products

Table 9 - Data Product Requirements

* Or on demand by an operator; with the exception of archive products which must be after post-flight processing is completed.

IT Security

3.3.82 The Radiosonde Observation Software shall comply with the following:

a. Federal Information Security Management Act (44 U.S.C.3544)

b. OMB’s implementing policies including Appendix III of OMB Circular A-130

c. National Institute of Standards and Technology (NIST) SP 800-53 Rev 4 (or newer).

d. Department of Commerce (DOC) IT Security Program Policy

e. NOAA IT Security Manual 212-1301 version 5.6 (or newer)

f. Security Controls for Federal Information Systems as outlined in Appendix E.

The Radiosonde Observation Software be compatible with control role-based permission access levels as outlined in security control AC-3 of the Recommended Security Controls for Federal Information Systems outlined in Appendix E.

Radiosonde Observation Software Documentation

3.3.83 The Radiosonde Observation Software documentation shall provide installation, preparation, maintenance and operation instructions.

Appendix A - No Data Message

A.1.1 No Data Messages If a flight fails at release and no data above surface is available or a flight will not be taken, the observer must send a No Data Message. The (TTAA), (TTBB), and (TTDD) messages must all be sent with the appropriate 101 groups when a flight was missed or no data is available above the surface.

The No Data Message shall include the (TTAA), (TTBB), and (TTDD) messages with the appropriate 101 groups when a flight was missed or no data is available above the surface. The 101 group is added after the 51515 message in the TTAA, TTBB and TTDD messages. The table below lists the possible 101 code figures.

NOTE: There are two different procedures that should be followed when a flight is missed.

1. When a flight is not possible for any reason, the observer must use the No Data option and add the proper 101 groups for the reason for no data.

2. When a flight is missed and another was possible, but not allowed - The observer must add a 10148 group after the 51515 message in the TTAA, TTBB and TTDD messages.

The 10148 group signifies that an ascent was not authorized.

The 10148 group should only be used when a second release is possible, but not allowed by NCEP or other approving authorities.

No Data 101 Group Code figures 101AdfAdf - Miscellaneous Regional Data

* Fading signals differ from weak signals in that "fading signals" are first received satisfactorily, then become increasingly weaker, and finally become too weak for reception, while "weak signals" are weak from the beginning of the ascent.

Appendix B - RADAT

Appendix C - Cloud/WX

This appendix provides the necessary tables and specific instructions to format the Clouds/Wx code. The Cloud/Wx code shall be entered in the Radiosonde Observation Software preflight information and it shall encode the cloud group into the WMO Coded Messages 41414 code group.

For those already familiar with synoptic code, you will notice some departure from conventional WMO coding procedures. If you simply observe the elements requested and report them according to tables provided in this text, the intent of the Clouds/Wx entry will be fully met.

Getting Started The Cloud/WX entry is a nine-digit, mandatory group. All nine digits shall be entered, regardless of the presence or absence of clouds or significant weather conditions.

The WMO format for entry of clouds and weather has been modified by the NWS to meet NCDC requirements. All stations using RRS software will follow this modified format, regardless of location; i.e., stations in either WMO Region IV or WMO Region V. A description of the nine-digit format follows:

1. Clouds/Wx group format: NhCLhCMCHWWWW Nh = Amount (in oktas) of the sky covered by all low clouds (CL) observed or the amount of sky covered by all the middle clouds (CM) observed. In no case will the amounts of the low and middle clouds be combined to report Nh. Use Table B-1 to report the amount of low or middle cloud coverage.

CL = Type of low cloud, based on the priority given in Table B-2. A solidus (/) is reported if CL clouds are not visible owing to fog or similar obscuring phenomena.

Note: Clouds are divided into three families, classified as low, middle, or high. The general height ranges for these are: surface to 6500 feet for low; 6500 feet to 20000 feet for middle; and above 20000 feet for high. Remember, these ranges are not absolute, but given as a guide only. More consideration may be given to the cloud form than the height in many cases. Each cloud family is coded with a single digit, 0 through 9. The code figure 0 is used to indicate that clouds are not present for a given family.

h = Height of the base of the lowest cloud observed. The height reported is with respect to the surface. The height is coded as a solidus (/) if there is a total surface-based obscuration that prevents an observation of the clouds. Use Table B-3 for the cloud base height.

CM = Type of middle cloud, based on priority given in Table B-4. A solidus (/) is reported if CM clouds are not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

CH = Type of high cloud, based on priority given in Table B-5. A solidus (/) is reported if CH clouds are not visible owing to fog or similar obscuring phenomena, or because of a continuous layer of lower clouds.

WWWW = Present weather coded in two groups of WW. These code groups are found in Table B-6. The coding starts with 99 (the highest priority) and descends to 00 (the lowest priority). Note that code figure 17 is placed out of numerical sequence to highlight its relative coding priority. You should note that present weather codes for some weather phenomena are events that have occurred during the past hour, not at observation time. When entering WWWW, go down Table B-6 and use the first and second applicable code figures. Note that two WW groups must always be coded, even if that means using the same code figure twice.

Table B-1: Amount of Low/Middle Cloud Nh Code Figure

Note: If there are any breaks in the sky at all, such as an overcast with a mackerel sky (altocumulus perlucidus or stratocumulus perlucidus), Nh would be encoded as 7. If there are only a few patches of low or middle cloud in the sky, Nh cannot be encoded as 0 but is encoded as 1. A partial obscuration does not affect the coding of Nh. A total obscuration is coded as 9, not 8 (overcast sky).

Table B-2 Coding of Low Cloud, CL This table presents the specifications for type of low cloud, CL, in order of priority. Go down the table and use the first applicable code figure.

(a) Cumulonimbus present, with or without other CL clouds

(b) No cumulonimbus present

1Consideration of predominance is restricted to the clouds corresponding to CL code figures 1, 5, 6 and 7, which have the same priority. Clouds of any one of these four specifications are said to be predominant when their sky cover is greater than that of the clouds of any of the other three specifications.

2'Bad weather' denotes the conditions which generally exist during precipitation and a short time before and after

Table B-3: Height of Cloud Base Above Ground, h

Note: This group is used to report the height of the base of the lowest cloud seen, regardless of cloud amount. The height reported is with respect to the surface.

The lowest cloud height is coded with a solidus (/) if there is a total surface-based obscuration that prevents an observation of the clouds.

Table B-4: Coding of Middle Clouds, CM This table presents the specifications for type of middle cloud, CM in order of priority. Go down the table and use the first applicable code figure.

(a) Altocumulus present

*There are several definitions of CM = 7 and each has a different priority; therefore CM = 7 appears several times in this code table.

(b) No altocumulus present

Table B-5: Coding of High Cloud CH This table presents the specifications for type of high cloud, CH, in order of priority. Go down the table and use the first applicable code figure.

(a) Cirrostratus present

(b) CH = 9 not applicable and no cirrostratus present

Use CH = 1, if the combined sky cover of cirrus in the form of filaments, strands or hooks is greater than the combined sky cover of dense cirrus, of cirrus with sproutings in the form of small turrets or battlements and of cirrus in tufts.

Table B-6: Coding of Present Weather, WW This table presents the specifications for present weather, WW, in order of priority. Go down the table and use the first and second applicable code figures. The code figure with the higher priority is reported as the first WW group and the code with the lower priority is the second WW group.