TRD.doc

ATTACHMENT

FA8217-12-R-5006

TECHNICAL REQUIREMENTS DOCUMENT (TRD)

FOR THE

AN/FMQ-19 Automatic Meterological Station 24 Feb 2011

FOR COORDINATION:

TBD

OO-ALC/GHSBG Mr David Shaw

TABLE OF CONTENTS

Paragraph Page

1.0. Introduction

1.1. Scope

2.0. Reference Documents

3.0. System Requirements

3.1. Introduction

3.2. System Characteristics

3.2.1. System Description

3.2.2. Sensors

3.3. Sensor Components

3.3.1. Wind Speed and Direction Sensors

3.3.2. Temperature and Dewpoint Sensor

3.3.3. Pressure Sensor

3.3.4. Visibility Sensor

3.3.5. Ceilometer

3.3.6. Liquid Precipitation Accumulation Sensor

3.3.7. Freezing Rain Occurrence Sensor

3.3.8. Precipitation Identification Sensor

3.3.9. Obscuration Reporting

3.3.10. Lightning and Thunderstorm Reporting

3.3.11. Runway Visual Range (RVR)

3.4. Environmental Limits

3.4.1. Site Elevation

3.4.2. Equipment Installed Indoors in a Conditioned Space

3.4.3. Equipment Installed Outdoors

3.4.4. Siting Criteria

3.4.5. Electromagnetic Interference

3.5. Reliability, Maintainability, and Availability Requirements

3.5.1. Availability (Uptime Ratio (UTR))

3.5.2. Reliability (Mean Time Between Critical Failure (MTBCF))

3.5.3. Data Quality Checks

3.5.4. System Diagnostic Capability

3.5.5. Continuous Self-Test

3.5.6. Built-In Test Equipment (BITE)

3.6. Field Data Collection Unit (FDCU)

3.6.1. Data sources

3.6.2. FDCU Timing and Control

3.6.3. FDCU Data Acquisition and Signal Conditioning

3.6.4. FDCU Data Communications

3.6.5. Power Control and Distribution

3.7. Terminal Data Acquisition Unit (TDAU)

3.7.1. TDAU Timing and Control Functions

3.7.2. Real Time Clock (RTC)

3.7.3. TDAU Data Acquisition and Communications

3.7.4. Data Processing

3.7.5. Data Formatting and Archival

3.7.6. Data Quality

3.8. Operator Interface

3.8.1. Peripherals and External Interfaces

3.8.1.1. Operator Interface Device (OID) Requirements

3.9. External Communication Interfaces

3.9.1. General Requirements

3.9.2. OID Port

3.9.3. User

3.9.4. Other Ports

3.9.5. N-TFS and JET Interface

3.10. Hardware Design and Construction

3.10.1. Uninterruptible Power Supply (UPS)

3.10.2. Special Packaging and Housing Considerations

3.10.3. Safety Criteria - Personnel Hazards

3.10.4. Electrical Overload Protection

3.10.5. Maintenance Monitoring Capability

3.10.6. Maintenance Data Format and Storage

3.11. Site Surveys, Site Preparation, Installation, Checkout, Calibration, and Acceptance Testing

4.0. Quality Assurance and Testing

5.0. Notes

6.0. Acronyms

LIST OF FIGURES

Figure 2.2.1-1 FMQ-19 Block Diagram Figure 2.4.4-1 Radiated Susceptibility Requirements for the FMQ-19 Figure 2.8-1 Operator Interface Display of Data for 10 Inch Monitors Figure 2.9-1 Communication Ports Functional Configuration Figure 2.9-2 OID Cabling

Figure 3.9-3 FMQ-19 Network Connectivity

LIST OF TABLES

Table 3.9-1 Required Data

Table 4-1 Verification Cross Reference Data

Table 5-1 Site Data

1.0. INTRODUCTION

1.1. Scope

A mission of the Air Force Weather Agency (AFWA) is to acquire standard systems for use at Air Force and Army locations worldwide. This document describes the capabilities of the AN/FMQ-19 Automatic Meteorlogical Station, a component of the Observing System 21st Century Fixed-Base System (OS-21 FBS). It is intended for use as a requirements document and as a management tool for systems engineering and integrated logistics support activities during the operations and support phase of the acquisition life cycle.

2.0 REFERENCE DOCUMENTS

FCM-H1-2005 Federal Meteorological Handbook 1 September 2005 Department of Commerce FCM-S4-1994 Federal Standard for Siting Meteorological Sensors at Airports August 1994 Department of Commerce

UFC 3-260-01 Airfield and Heliport Planning and Design 17 November 2008 Department of Defense

AFMAN 15-111 Surface Weather Observations 10 March 2009 Department of the Air Force

Federal Standard Algorithms for Automated Weather Observing Systems Draft

Department of Commerce

3.0. SYSTEM REQUIREMENTS

3.1. Introduction

This section presents the system requirements for the FMQ-19. Included are the system characteristics in Section 3.2, which includes a system description of major sub-assemblies. Section 3.3 presents the detailed requirements for each sensor component. Section 3.4 sets forth the operational environments for the FMQ-19. Detailed hardware requirements are described in Sections 3.5 through 3.10.

3.2. System Characteristics

3.2.1. System Description

This section provides an overview of the FMQ-19 and its intended operation. The system must remain capable of accurately sampling, measuring, and reporting temperature, wind speed and direction, visibility, cloud base height and amount of coverage, pressure, liquid equivalent precipitation accumulation, day/night and ice accretion during freezing precipitation. These measurements are used to derive elements that are required to create properly formatted, fully automated observations that comply with applicable World Meteorological Organization (WMO) and US governmental standards. The FMQ-19 shall comply with the standards of the Federal Meteorological Handbook No. 1 (FCM-H1-2005), "Surface Weather Observations and Reports", and may include the use of Federal Standard Algorithms (that are currently managed by the NWS) in the processing of sensor data and generation/quality control/dissemination of surface weather observations. The proposed system must be adaptable/flexible/expandable. The FMQ-19 sensors are existing products currently or previously offered for sale and the sensors comply with Section 3.3. Automated lightning detection sensors integrated into the sensor suite will serve a capability to detect/observe lightning. Sensor output signals from automated sensors will be transmitted directly to an Operational Weather Squadron (OWS) and to local operational users through standard forecast/analysis systems. The FMQ-19 is characterized by having high reliability and availability, expansion capability for both sensors and outputs, immunity to induced or applied transients on signal and power lines, and by having all software required for data processing, display, and storage. The system must be capable of utilizing indigenous power sources. The FMQ-19 shall be capable of automatically sensing when the air traffic controllers change the active runway. This is required so data that comprise surface weather observations are representative of active end of the instrumented runway. The FMQ-19 shall produce the following observations:

3.2.1.1. One-Minute Observation (OMO) produced each minute in a fixed format for transmission.

3.2.1.2. Aviation Routine Weather Reports/Aviation Selected Special Weather (METAR/SPECI), the traditional weather message that is distributed via the Air Force/NWS/FAA national circuits. METAR/SPECI reports are produced hourly and when special criteria are met.

Figure 3.2.1-1, FMQ-19 Block Diagram, indicates a typical FMQ-19 system configuration. As defined in the Site Table, equipment (sensors, system, sub-system, displays, outputs and interfaces.) may be added or removed to create the configuration that is best suited to each installed location.

3.2.2. Sensors

The sensor group(s) shall be comprised of environmental sensors capable of measuring the required meteorological variables. These sensors shall provide signal outputs representing the sensed weather element data, via contractor provided conductors (hardwire or fiber optics) to the Field Data Collection Unit (FDCU).

3.2.2.1. Sensors for use in FMQ-19 shall be selected and installed by the contractor. Sensors shall comply with the functional and environmental requirements specified in Section 3.4 as well as the reliability, availability, and maintainability performance specified in Section 3.5. The following are general requirements that apply to all sensors:

3.2.2.1.1. Sensors selected by the contractor shall be Federal Meteorological Handbook 1 (FMH-1) and WMO compliant.

3.2.2.1.2. Sensors shall be interchangeable (i.e., not specifically designed for individual sites) and shall not require individual site adjustments except for calibration constants.

3.2.2.1.3. Sensor data shall be encoded into digital form either at the sensor or in the FDCU.

3.2.2.1.4. Sensors that have the built in test capability shall be routinely and automatically exercised/tested. Tests may be BIT or exercised externally whenever a sensor test fails; the sensor shall be reported missing. The sensor shall also have the capability of being tested externally, via the serial interface at the FDCU and at the Terminal Data Acquisition Unit (TDAU) via the Operator Interface Device (OID).

3.2.2.1.5. Sensor output does not have to be linear; however, sensors shall conform to a fixed transfer function. Calibration constants for a sensor may be entered into the system when a sensor is installed. These constants can be site specific, and shall be kept to a minimum.

3.2.2.1.6. The sensor performance requirements apply not to the sensor alone, but to the sensor as it is used in the system, e.g., any degradation in the measured parameter because of system processing must be accounted for in meeting the reliability, maintainability and availability (RMA) requirements.

3.2.2.1.7. Every effort shall be made to obtain sensors that meet the outdoor environmental requirements specified in Section 3.4. However, some of the Commercial and Non-Developmental Item (CaNDI) sensors may not be able to meet these environmental requirements and will have to be accepted anyway. These may be upgraded when improved sensors become available. (Reference ORD paragraph 1.2).

3.3. Sensor Components

3.3.1. Wind Speed and Direction Sensors

The wind range of the wind speed sensor shall be 0-115 knots, with an accuracy of +/-1 knot (0-24kts) and +/- 10% above 24kts. Resolution shall be 1kt. Display real-time wind updates.

3.3.1.1. The wind direction accuracy shall be within 5 degrees. The resolution shall be 10 degrees (0 to 359 degrees). The wind direction sensor shall be aligned to true north. After removing the sensor from its mounting for maintenance, the sensor design shall enable the accurate restoration of directional alignment without the necessity for another alignment survey.

3.3.1.2. The wind speed and direction sensors shall operate within the accuracy requirements specified, during conditions of 0.25-inch radial thickness of clear ice and wind speeds higher than 10 knots. The sensors shall be sampled at a rate sufficient to provide five-second averages.

3.3.2. Temperature and Dewpoint Sensor

The temperature sensor shall measure temperature from –62 C to +54 C. The accuracy shall be 1 C with a resolution of 0.1 C. Temperature will be reported/displayed to the nearest whole degree Celsius and Fahrenheit.

3.3.2.1. Dew point data may be derived from a Relative Humidity Sensor. Data shall range from -34 C to +30 C. The resolution shall not be greater than 0.1 C and accuracy of:

+/- 2.2 C for -34 C to -18 C.

+/- 1.7 C for -18 C to 0 C

+/- 1.1 C for 0 C to +30 C

3.3.2.2. Relative Humidity shall be reported/displayed to the nearest whole percent with a range of 5% to 100% with an accuracy of +/- 5%.

3.3.3. Pressure Sensor

Three sensors are required per system. The pressure sensors shall measure the barometric pressure when installed at locations at any elevation between 0 and 10,000 feet above mean sea level. Each sensor shall meet the following:

3.3.3.1. Range: High pressure shall be 1100 hPa (hectopascal) and low pressure shall be 600 hPa.

3.3.3.2. Accuracy: +/- 1 hPa.

3.3.3.3. Resolution: 0.003 inch Hg (mercury).

3.3.3.4. Venting: The contractor shall provide outside venting as required by Federal Standard For Siting Meteorological Sensors at Airports (FCM-S4-1994).

3.3.3.5. Interrogation Rate: The pressure sensors shall be interrogated once every 10 seconds.

3.3.3.6. Differential Accuracy: Each sensor shall exhibit a differential accuracy of 0.01 inch of mercury or less between any two pressure measurements taken from the same sensor 3 hour apart. Ambient temperature over this 3-hour period shall not vary more than 5 F. Ambient pressure shall not vary more than 0.1 in. Hg over the 3-hour period.

3.3.3.7. Pressure shall be reported in Hg and displayed in Hg or Hg and hPa as a selectable set up option with an accuracy of +/- 0.02 in Hg and a resolution of 0.01 in Hg.

3.3.3.8. Altimeter Setting accuracy shall be +/- 0.02 in Hg and a resolution of 0.01 in Hg.

3.3.3.9. Sea-Level Pressure accuracy shall be +/- 0.68hPa and a resolution of 0.1hPa.

3.3.3.10. Station Pressure accuracy shall be +/- 0.02 in Hg and a resolution of 0.005 in Hg.

3.3.3.11. Pressure Altitude accuracy shall be to the nearest 10 feet (ft).

3.3.3.12. Density Altitude accuracy shall be to the nearest 10 ft.

3.3.3.13. Pressure Trend/Tendency shall indicate character of pressure change over the last 3 hours, in tens, units, and tenths of hPa.

3.3.3.14. Pressure Falling/Rising Rapidly shall determine fall/rise in station pressure at the rate of 0.06 in Hg (2.0 hPas) or more per hour with a total fall/rise of at least 0.02 in hg (0.7 hPas at time of an observation).

3.3.4. Visibility Sensor

The visibility sensor shall provide an extinction coefficient equivalent to visibility up to and including 10 miles.

3.3.4.1. Reportable values in statute miles (SM). 0 through 1 ¼ SM (accuracy +/- ¼ SM); 1 ½ through 1 ¾ SM (accuracy +1/4, -1/2 SM); 2 through 2 ½ SM (accuracy +/- ½ SM); 3 SM (accuracy +1/2, -1 SM); 4 through 10 SM (accuracy +/- 1 Reportable Value). The FMQ-19 software shall allow editing to include visibility increments less than ¼ mile and greater than 10 miles in accordance with AFMAN 15-111. Code and report the prevailing visibility (VVVV) in meters using four digits at overseas locations. Code and report the prevailing visibility (VVVVVSM) using up to 5 digits, and the statute mile indicator (SM) at US locations. When reference is made to the geographic area "United States," the implication is that US procedures will apply to all 50 states and Guam. The US and Guam will use statute miles for visibility values while overseas locations will use the metric system (meters).

3.3.4.2. A photometer shall be provided with the visibility sensor to indicate whether the ambient light level is day or night. It shall always indicate day for illumination > 3 foot-candles (FC) and night for illumination < 0.5 FC. Transition from indicating night to indicating day shall occur once in the region between 0.5 and 3.0 FC (as the illumination increases). Transition from indicating day to indicating night shall occur once in the region from 3 to 0.5 FC (as the illumination decreases). The photometer shall have diagnostics associated with it so that Remote Maintenance Monitoring (RMM) can verify that it is operational.

3.3.4.3. The photometer shall be mounted facing the north sky and shall operate with ambient levels up to 50 FC. The sensor shall be such that snow buildup shall not interfere with its operation. When sites have multiple visibility sensors, provision shall be made to select only one photometer for use in determining the extinction to visibility conversion based on the day/night photometer output.

3.3.4.4. Different sensor calibrations may be used for different weather types (i.e., rain, and snow) as provided by the precipitation identification sensor.

3.3.4.5. The visibility sensor and photometer shall be interrogated as required to obtain a one-minute average.

3.3.5. Ceilometer

The cloud height sensor shall have a design range of 12,000 feet or greater. The sensor shall provide an output of three cloud layers representative of the sky conditions when surface visibility is equal to or greater than ¼ mile; properly code/report surface based partial obscurations, cloud layer(s) and obscuration layer(s) aloft, indefinite ceilings or a clear sky (SKC) in ascending order of height up to a maximum of three groups; code/report variable ceiling in eighths such that SKC is 0 eighths (fully automated locations use CLR when no layers at or below 12,000 feet are detected; manual augmented locations use abbreviation SKC when no layers are reported), FEW is a trace to 2 eighths, SCT is 3 to 4 eighths, BKN is 5 to less than 8 eighths, OVC is 8 eighths, and VV is used for an indefinite ceiling; and provide a variable ceiling accuracy of +/- 1 Reportable Value.

3.3.5.1. Range: The sensor shall measure cloud heights and the heights of obscuring phenomena aloft to a minimum of 12,000 feet or better.

3.3.5.2. Accuracy: Code/report cloud bases up to three layers surface to 12,000 ft; accuracy to the nearest 100 feet for cloud layers surface to 5,000 ft, nearest 500 feet for layers >5,000 ft but < or = 10,000 ft, and nearest 1,000 ft for layers greater than 10,000 ft; Accuracy +/- 3 Reportable Values, Minimum detectable cloud thickness 100 ft. Under laboratory conditions, the sensor shall provide an accuracy of 100 feet or 5 %, whichever is greater.

3.3.5.3. Eye Safety: The ceilometer sensor shall be designed to have accessible emission limits for laser radiation, with Class 3B maximum accessible emission level applied to direct viewing without optical instruments (excluding ordinary eyeglasses).

3.3.6. Liquid Precipitation Accumulation Sensor

The liquid precipitation accumulation sensor shall be capable of measuring the amount of precipitation accumulation within a range 0 to 3 in/hr accumulation; able to measure liquid precipitation amounts and the water equivalent of freezing and frozen precipitation; resolution 0.01 in; accuracy +/- 0.02 in or 5% of the hourly total (whichever is greater); accumulation reporting hourly, 3, 6, 24 hr synoptic times, midnight LST. Measure freezing rain accumulation rates greater than or equal to 0.01 in/hr.

3.3.6.1. This sensor shall be interrogated once per minute.

3.3.7. Freezing Rain Occurrence Sensor

The freezing rain occurrence (FZRA) sensor shall be capable of detecting freezing rain correctly 99% of the time whenever freezing rain has accumulated to 0.01 inch. The sensor false alarm rate shall not exceed 0.01% when there is no precipitation, or when there is rain at temperature above 4.4 ºC.

3.3.7.1. The sensor shall be interrogated once per minute to provide reports of onset and cessation each minute.

3.3.8. Precipitation Identification Sensor

The precipitation identification sensor shall meet the following requirements:

3.3.8.1. The rainfall and wet snowfall detection threshold shall be a rate of 0.01 inch per hour, as measured using a standard National Weather Service (NWS) Heated Tipping Bucket Gauge.

3.3.8.2. The precipitation rate accuracy shall be the larger of 10% or 0.01 inch/hr.

3.3.8.3. The solid precipitation shall be correctly detected at least 99% of the time

(reported as either “S” or “P”) and shall be correctly identified at least 97% of the time.

3.3.8.4. The liquid precipitation shall be correctly detected at least 99% of the time

(reported as either “R” or “P”) and shall be correctly identified at least 90% of the time.

3.3.8.5. The false alarm rate shall be less than or equal to 0.2%.

3.3.8.6. The sensor shall provide sufficient data to the present weather algorithm so that the following weather situations can be identified:

Light Rain

(R-)

Moderate Rain

(R)

Heavy Rain

(R+)

Light Snow

(S-)

Moderate Snow

(S)

Heavy Snow

(S+)

Mixed or other Precipitation (P)

3.3.8.7. The sensor shall report the start and end of a precipitation event within five minutes of the time that it occurs.

3.3.8.8. The sensor shall be interrogated once per minute.

3.3.9. Obscuration Reporting

The following obscurations, at a minimum, must be reported: fog, mist, freezing fog, and haze.

3.3.10. Lightning and Thunderstorm Reporting

A stand-alone lightning sensor is required. The lightning sensor shall detect cloud-to-cloud and cloud-to-ground strikes. Within 5 nautical miles (nm), report as thunder showers (TS) in the body of the report with no remark. Between 5 and 10 nm, report as vicinity thunder showers (VCTS) in the body of the report with no remark. Beyond 10 nm but less than 30 nm, report in remarks only as lightning distant (LTG DSNT) followed by the direction. Poll and process data from the sensor once a minute. Provide the capability to view the raw sensor data cloud-to-ground and cloud-to-cloud strikes. All strikes shall be counted, but only the cloud-to ground strikes will be used to generate an estimate of the range. Cloud-to-ground strikes shall be grouped and displayed in three range bins: 0 to 5 miles, 5 to 10 miles, and 10 to 30 miles. Cloud to cloud strikes shall all be grouped and displayed is a single bin 0 to 30 miles.

3.3.11. Runway Visual Range (RVR)

Report RVR data during periods when prevailing visibility is 1 mile (1,600 meters) or less or RVR is 6,000 feet (1,830 meters) or less. RVR is required to support instrument landing system (ILS) Category I, Category II, or Category III system depending on the airfield. For operations below 1,600 RVR or 0.5 km (1/3 mile), two transmissometers or visibility sensors are required to provide visibility information at the approach and rollout end of the runway. NOTE: In order to have an accredited Category II instrument landing system, FAA standards require ATC (Air Traffic Control) agency access to digital readout of touchdown RVR data and to display real-time update of RVR.

3.3.11.1. RVR-Local. The unit of measurement will be the same as that published for the station in the Department of Defense (DoD) Flight Information Publication (FLIP). When no RVR minima are published in the DoD FLIPs, report locally in meters if prevailing visibility is locally disseminated in meters; use feet if prevailing visibility is reported locally in statute miles.

3.3.11.2. RVR-Longline. The unit of measurement in the US will be feet (FT), and all transmissions will have "FT" appended. Overseas units will use measurement values as published in the DoD FLIPs. When no RVR minima are published in the DoD FLIPs, report locally in meters if prevailing visibility is locally disseminated in meters; use feet if prevailing visibility is reported locally in statute miles.

3.4. Environmental Limits

The FMQ-19 shall operate under and/or withstand the environmental conditions described below.

3.4.1. Site Elevation

The system, subsystems and components shall operate from 100 feet below sea level to 10,000 feet above sea level.

3.4.2. Equipment Installed Indoors in a Conditioned Space

Computer equipment will be expected to operate in temperatures ranging from +4 C. Some CaNDI computer equipment may not meet these environmental requirements for operation and storage. This equipment will be accepted for use in a conditioned environment and may have to be shut down when the environment exceeds the limits of the equipment. Transportation requirements will be met with enhanced packaging procedures prior to shipment or storage.

C to +60 C and storage/transportation temperatures from –51 C to +40

3.4.3. Equipment Installed Outdoors

3.4.3.1. Operating Temperature: from -62 C to +54 C. Storage/Transport Temperature: from -51 C to +60 C.

3.4.3.2. Relative Humidity: 0% to 100%.

3.4.3.3. Wind: Up to 115 knots.

3.4.4. Siting Criteria

Special care is necessary in selecting appropriate locations for installation of sensors to assure that the resultant observations are representative of the meteorological conditions affecting aviation operations. The FDCU primary suite of sensors (identified above) and FDCU discontinuity groups (a subset of the primary FDCU sensors) must be located between 250 feet (75 meters) and 500 feet (150 meters) from centerline of the runway and approximately 750 feet (230 meters) to 1,000 feet (300 meters) of the designated runway threshold. Siting of sensors more than 500 feet (150 meters) from centerline of the runway provides data less representative of the runway and therefore could have a negative affect on aviation operations. Siting of the sensors less than 250 feet (75 meters) would violate the frangibility zone. Equipment will be mounted on concrete footings or foundations with no concrete edges above ground level with a break point no higher than 3 inches above grade. Weather equipment must be adequately supported to be stable during high winds and be able to support system, ice and wind loads. These severe conditions are the very weather elements that the automated weather observing systems are supposed to measure and provide data for safety of flight. The equipment mountings will be designed to support the desired equipment load to eliminate vibration and swaying which can result in erroneous readings. The contractor shall reference the latest version of the Airfield and Heliport Planning and Design (UFC 3-260-01), the Federal Standard for Siting Meteorological Sensors at Airports (FCM-S4-1994), and the Federal Meteorological Handbook 1 (FCM-H1-2005) as guidelines for siting sensors at airfield runways and other locations.

3.4.5. Electromagnetic Interference

The OS21 systems shall be electromagnetically compatible within itself and with other systems in its operating environment. The operational performance shall not be degraded by electromagnetic environmental effects (E3). Systems will also comply with the applicable DoD, National, and International spectrum management policies and regulations. The FMQ-19 shall operate in an electromagnetic environment as defined in Figure 3.4.4-1.

3.5. Reliability, Maintainability, and Availability (RMA) Requirements

The FMQ-19 shall meet or exceed the following requirements:

3.5.1. Availability (Up-time Ratio [UTR]). Observing systems will have a designated UTR for the critical path of 96%. UTR is expressed as:

UTR = (total operating hours - total down-time) / (total operating hours)

3.5.2. Reliability (Mean Time Between Critical Failure [MTBCF]). Observing systems will have a designated MTBCF. MTBCF is a measure of the average time between failures of mission-essential system functions. A critical failure is a failure that prevents the system from performing its assigned mission to observe, process, store, and transmit data for more than one (1) hour. This includes all critical hardware and software failures that occur during mission and non-mission time, and is expressed as:

MTBCF = (number of operating hours) / (number of critical failures)

Must have a MTBCF of at least 2,200 hrs.

3.5.3. Data Quality Checks. FMQ-19 algorithms shall contain data quality checks (e.g., dewpoint greater than temperature, reporting of snow with temperature above 3.3C, excessive rate of change), which shall be implemented in the operational software. In addition, trends shall be continuously monitored and analyzed to determine deterioration of sensor performance. Whenever a potential degradation of data quality is detected, the FMQ-19 shall alert the operator, via the OID, of a sensor malfunction and note the problem in the maintenance log. The operator alert and the maintenance log shall identify the specific data check that failed.

3.5.3.1. The system shall detect:

Loss of signal or power cables (i.e., open or shorted cables)

Removal or failure of any critical Line Replaceable Unit (LRU) which would result in a system critical error or system failure.

Any indication of sensor failure or degradation (e.g., low laser power in the Ceilometer).

3.5.4. System Diagnostic Capability

Since the FMQ-19 will be providing critical weather information to support aviation operations, it is essential that the system be able to self-detect performance degradation to avoid reporting incorrect data. To support this mission, the FMQ-19 shall have two- (2) levels of diagnostic capability: continuous self-testing that runs automatically, and specific tests plus sensor dialogue that are run on demand by an operator/technician.

3.5.5. Continuous Self-Test

The continuous self-test shall check all electronic LRU functions for the FDCU, TDAU, sensors, buses, and communications. Equipment status and performance shall be automatically and continuously analyzed to determine trends signifying degraded operation. Error messages shall be displayed on the Operator Interface Device (OID) and include interpretation and advice in English, detailing specifics on failures, actions required, identification of marginal or degraded system operation, and identification of specific LRUs which need to be replaced. The self-test shall be designed to detect an out-of-tolerance condition that is specified by a manufacturer or developed by the contractor.

3.5.6. Built-In Test Equipment (BITE). In order to isolate the failure to a LRU, the maintenance technician may use this additional level of diagnostic capability. This would include a provision for direct dialogue with sensors. The technician shall be able to operate BITE remotely from the TDAU.

3.6. Field Data Collection Unit (FDCU)

Note: The requirements for the FMQ-19 design include subsystems for collecting sensor data (FDCU) and data processing [Terminal Data Acquisition Unit (TDAU)]. The FMQ-19 system as designed may allocate the functions described for the TDAU and FDCU differently than they are allocated herein, as long as all functions are accounted for, except that I/O ports for telecom and displays must be located in the TDAU.

3.6.1. Data Sources

Each FDCU shall have the capability to acquire data from the following sensors. Multiple FDCUs may be required within one installation.

Wind Speed

Wind Direction

Temperature and Dewpoint

Liquid precipitation accumulation

Freezing rain occurrence

Precipitation identification

Cloud height

Visibility (including day/night sensor)

Barometric sensors (triple redundancy)

Lightning sensor

Also, the FDCU shall have the capability to receive status signals from sensors as required, including supply voltage, current and heater operation. Each FDCU shall incorporate built-in-test capability. Each FDCU shall have the capability (e.g., connector and board slots, RAM/ROM spaces) to include all hardware and software necessary to accommodate at least five additional sensors. These sensors, which may be any combination of the above sensor types, or additional new types (e.g., snow depth), for a total capacity of 16 inputs.

3.6.2. FDCU Timing and Control

Timing and control functions include sequencing and control of data acquisition, signal conditioning, scaling and conversion, storage, data formatting, commands and data transfer, and test modes. Data transmissions to the TDAU shall not interfere with each other. A “watch-dog” timer shall be provided to produce a system reset/re-boot in the event of hardware malfunction or unrecoverable software error.

3.6.3. FDCU Data Acquisition and Signal Conditioning

Means shall be provided to acquire the instantaneous values of the sensor signals. The preconditioned signals (analog, digital, or other) shall be converted to digital words. The contractor may elect to transfer the sensor data from the FDCU to the TDAU in engineering units. If so, the FDCU shall contain the scaling coefficients and perform the conversions. Means shall be provided for bi-directional communication (via the FDCU) between the TDAU and sensors with support for BIT/self-test. Testing of sensors shall not adversely affect the operation of sensors not involved in the test.

3.6.4. FDCU Data Communications

Data communications from the FDCU to the TDAU shall be serial digital transfer via cable. The installed system shall conform to the EMI/RFI requirements of section 3.4.5.

3.6.5. Power Control and Distribution

The FDCU and TDAU shall be provided with an Uninterruptible Power Supply (UPS) system described in Section 3.10.1. Loss of primary power to the FDCU, TDAU, and all associated sensors and peripherals shall not result in degradation or loss of performance for at least 20 minutes. After a 20 minute loss of primary power or when the back-up battery can no longer provide the minimum back-up power, whichever is greater, the FDCU and TDAU shall save any necessary information in nonvolatile memory to automatically restore normal operation when power is returned. The FDCU and TDAU shall then perform an orderly shutdown. After a shutdown has occurred and power is restored, the FDCU shall automatically restart all data files and re-boot, if necessary, from TDAU firmware. For the TDAU, upon restoration of normal power after a shutdown, a record of the power outage shall be output to the printer and archived in the maintenance log, and the system shall automatically restart all functions.

3.7. Terminal Data Acquisition Unit (TDAU)

The TDAU shall acquire, process, format, store, and report data. It shall operate continuously in the office environment specified in Section 3.4.2, and meet the RMA requirements of Section 3.5. The unit shall accept up to three OIDs for keyboard interaction with the system. The TDAU shall accept inputs from the FDCU. It shall contain the system hardware and firmware/software necessary to perform the following:

system timing and control data acquisition and communications data processing data formatting and storage data quality checks archiving power control and distribution system diagnostics data output

3.7.1. TDAU Timing and Control Functions

The system shall control and schedule the following: time out and restart when processes are interrupted or nonfunctional; manual entry and display functions; synchronous data collection; synchronous one-minute observations; METAR, and SPECI reports. The TDAU shall have a watchdog timer to provide a system reset in the event of software malfunction.

3.7.2. Real Time Clock (RTC)

3.7.2.1. Prior to TCTO 31M1-FMQ19-TBD and fielding of the JET, the FMQ-19 shall use a Real Time Clock (RTC) as a time reference for all events within the TDAU, and shall be a product of the processor. Typically, days, hours, and seconds are provided as a system output for use in system displays. The day shall be expressed in the Gregorian Calendar. Hours and minutes shall be indicated numerically from 0000 to 2359. The clock function shall be accurate within 15 seconds each month. The operator shall be able to set or reset the RTC, using an OID. The RTC shall contain a rechargeable long-term (minimum 2 years) or non-rechargeable 5-year back-up power supply to maintain the clock at specified accuracy during AC power outages. Timing shall be provided for all data acquisition, communication and processing functions. Control functions include data acquisition, operating peripherals, and reporting data via communication ports.

3.7.2.2. After TCTO 31M1-FMQ19-TBD and replacement of N-TFS by JET, time reference shall be synchronized with the JET interface.

3.7.3. TDAU Data Acquisition and Communications

All sensor data acquisition shall be via the FDCU. Additional interfaces shall be provided to communicate with multiple OIDs, one observer notification device, various communication circuits. Communication protocol and interface requirements for communication circuits are described in Section 3.9.

3.7.4. Data Processing

The following data processing capabilities shall be provided:

3.7.4.1. Convert data received from sensors into engineering units (if not performed by the FDCU).

3.7.4.2. Average the measurements as appropriate for each weather element.

3.7.4.3. Calculate the one-minute observation for display and long line transmission.

3.7.4.4. Prepare hourly METAR/SPECI messages at the hourly report time, +/- 5 minutes around the hour + 55 minutes. The METAR/SPECI messages shall be transmitted at the hourly transmission time. The METAR report shall be adjustable in 1 minute increments over a +/- 5 minutes period around the hour + 55. The transmission time shall be adjustable in 1-second increments from 1 second to 5 minutes following hourly report time.

3.7.4.5. Provide notification via alarms to operators whenever a METAR or SPECI observation is prepared.

3.7.4.6. Provide notification of the form “METAR PENDING” or “SPECI PENDING” on the top of one-minute screen while a METAR or SPECI observation is pending (i.e. edit time has not expired).

3.7.4.7. Continuously monitor data thresholds to determine if special reports are required e.g., ceiling minimums, thunderstorms, and freezing rain. Prepare a SPECI using METAR format whenever processing of an algorithm calls for one. The SPECI transmission shall be within 5 minutes after detection of the need for a special report, adjustable in 1-second increments. Processing shall continue during the period between detection and transmission of the Special Observation. If the processing indicates a need for another SPECI then:

3.7.4.7.1. If the second special is caused by reversal of the ceiling or visibility trend, which caused the initial special, neither shall be transmitted. A message shall be sent to the OID screen(s) indicating that the SPECI was canceled.

3.7.4.7.2. If the second special is caused by continuation of the ceiling or visibility trend, which caused the initial special; or if the second special is caused by a different parameter than the initial special, the first special shall be deleted and not transmitted. The second special shall be transmitted after allowing an edit period and archived in normal fashion.

3.7.4.7.3. If the METAR report time occurs while a special is pending, the special shall be deleted and the METAR observation shall be transmitted at the hourly transmission time.

3.7.4.7.4. If a METAR observation is pending when a special continuation occurs, delete the specials and transmit the METAR at hourly transmission time.

3.7.4.7.5. If a METAR observation is pending when a SPECI reversal occurs, cancel the SPECIs, and transmit the METAR at the hourly transmission time.

3.7.4.8. Perform quality checks of the parameters. This shall include sensor out-of-limits checks plus time continuity and comparison checks. When errors are detected, the system shall discontinue reporting of the affected parameters. It shall provide notification via alarms to the OID. The system shall provide identification of the fault by appending a status character to the METAR, and storing the fault identification as maintenance data. If sensor quality is restored, the system shall restart parameter reporting and note restoration/repair in the maintenance log. However, pressure reporting shall never be restarted automatically after an error has been detected.

3.7.4.9. Continuously monitor operator interface functions to incorporate operator changes that affect the algorithm processing and data output.

3.7.4.10. Continuously monitor precipitation accumulation data thresholds to determine if METAR or SPECI reports are required.

3.7.4.11. Prepare a special or urgent special when requested by an operator.

3.7.5. Data Formatting and Archival

The FMQ-19 system shall retain a record of the OMO/METAR/SPECI reports, as well as the data entered through the keyboard, for use by accident investigators. The interval between archived reports shall not be more than 20 minutes, and the report shall be retained for at least 96 hours (4 days) (i.e., 96 hours of data is archived on a last in, last out, sequence). A method shall be provided for the retrieval of archived reports using a computer disk or other permanent record (e.g., a hard copy print out), and the operator shall be able to suspend the updates of the archived weather reports to freeze the data until retrieval may be accomplished. A CD Read Write capability is required to provide adequate file back up for certification and accreditation requirements. The capability must provide back-up for site-specific configuration data necessary to restore the system.

3.7.5.1. Maintenance data – archived for 31 days plus current date’s data.

3.7.5.2. Aircraft Accident Archival. A two-hour period of data shall be permanently archived at operator request.

3.7.6. Data Quality

Sensor self-test status signals and data quality checks shall be processed by the TDAU to assure that RMA requirements are fully met. Whenever this processing indicates that a parameter should be missing, the system shall activate audible and visual alarms and replace the appropriate parameters with “M”. Alarms shall not be activated if a parameter is reporting missing due to report processing being turned off by the operator. Sensor data shall remain accessible to an operator via the OID functions. The status character shall be appended to all METAR messages until, a technician has taken corrective action. FMQ-19 shall employ error detection and correction on all information transmitted on communication circuits.

3.8. Operator Interface

3.8.1. Peripherals and External Interfaces

The peripheral equipment specified for each FMQ-19 site in the Site Table shall be interfaced with the TDAU and shall include OIDs.

3.8.1.1. OID Requirements.

The OID shall consist of a video display, and a keyboard, which may be an integrated desktop unit. The primary OID shall be located up to 100 feet from the TDAU and shall be capable of transmitting/receiving at a minimum rate of 9600 baud at that distance. The contractor shall provide the capability to extend the distance of a primary or secondary OID beyond 100 feet, with a 9600-baud or higher transmission rate modem if a single cabinet system is proposed.

3.8.1.1.1. The OID display shall be readable by a person with normal vision (corrected to 20/20) in levels varying from normal office lighting to near darkness, at angles up to 45 degrees to the plane of the display, and at a distance of 6 feet. The screen shall be non-glare and rectangular. There needs to be a 10 inch diagonal display available for tower and RAPCON OIDs, and up to 15 inch diagonal displays available for weather personnel and maintainer OIDs. The tower and RAPCON OIDs must display data similar to the one shown in Figure 3.8-1. The device shall include a variable intensity audible alarm for weather and maintenance OIDs.

3.8.1.1.2. The minimum acceptable display resolution shall be 640 x 200 pixels.

3.8.1.1.3. The display shall be flicker-free with an update rate of at least 60 Hz.

3.8.1.1.4. The display shall be at least (8) eight colors.

3.8.1.1.5. Character box shall be at least 8 pixels wide by 8 pixels high.

3.8.1.1.6. Control shall consist of at least:

ON/OFF switch

Contrast control

Brightness control

Audible alarm intensity

3.8.1.1.7. This display shall accept data from the TDAU and display that data for operator interaction through the keyboard. The display shall have a highlighting capability (e.g., varying colors, varying levels of brightness or reverse video). Any character at the cursor position shall always be clearly visible.

3.8.1.1.8. The OID keyboard shall provide active function keys, and separate active cursor control keys for performing the OID functions. Keys shall have tactile feedback, and shall have a layout similar to a standard PC keyboard.

3.8.1.1.9. When the TDAU OID port is active, and it is the only active OID port, the OID shall operate at a speed of at least 9600 bps.

3.8.1.1.10. The operator must be able to interact with the FMQ-19, performing various functions through the OID. All operator functions must be accessible through all on-site OIDs. The remote maintenance function shall not be available until after the user provides secure authentication. Passwords shall be provided for each type of user.

3.8.1.1.11. Simultaneous execution of OID commands from more than one terminal is not required; however, response to and servicing of more than one terminal simultaneously is required.

3.8.1.1.12. FMQ-19 shall disconnect communications with an unsigned remote user after 5 minutes has elapsed from the completion of the last transmission to that remote user.

3.8.1.1.13. A general description of OID functions is given below.

3.8.1.1.13.1. The OID shall notify operators by audible alarm of variable intensity and visual alarm under control of the TDAU. The audible alarm shall not last more than one minute and shall be easily disabled by the operator both against future alarms, and when it sounds. A message shall be displayed (on the one-minute screen) which indicates the status of the alarms.

3.8.1.1.13.2. When a METAR or SPECI is available for edit, (i.e., pending) the pending observation shall be displayed on the one-minute screen in place of the transmitted observation.

3.8.1.1.13.3. The following functions shall be available to all signed on operators (ATC has limited capability as defined under ATC functions):

3.8.1.1.13.3.1. Sign ON/OFF. Only one observer shall be signed on the system at any given time. Only one controller shall be signed on at given time.

3.8.1.1.13.3.2. Review the files listed below:

Observations (METAR)

One-minute data

Current sensor data

Site-specified data (except external communications data, available only to technicians and system managers)

Maintenance Log

Communications Log ne-minute observations for the past 12 hours

Archived observations for selected 2 hour period during the past 4 days

3.8.1.1.13.3.4. Pull down menu for the following functions. WEATHER, USERS, SENSORS IN MANUAL mode, shall be available. The data provided for WEATHER, USERS, and SENSORS IN MANUAL mode shall be updated each minute.

3.8.1.1.13.3.5. Turn off report processing such that if left in automatic mode the output to the general display and observations shall be “M” for missing. If report processing is turned off, on the next update of the One-Minute screen, the “M” shall be highlighted and an alarm shall sound for 1 minute. Sensor data shall remain accessible for review via the OID function. The status character shall be appended to all METAR surface aviation observations until corrective action has been taken.

3.8.1.1.13.3.6. Whenever Report Processing is turned off for the precipitation identifier sensor or if the sensor is reconfigured or disabled, the system shall examine the user status to see if an observer (OBS) is signed on:

If an OBS is not signed on, the system shall delete the automated present weather remark and generate the remark PWINO until report processing is turned back on or the sensor is reconfigured or enabled. The letters “PWINO” shall be flashed in a high contrast color for a period of one minute on the bottom of the one-minute screen. The message “PWINO” shall continue to be displayed until report processing is turned back on or the sensor is configured or enabled. The remark FZRANO shall also be appended if the five-minute ambient temperature is less than or equal to 36 degrees F or is missing. The remark FZRANO shall not be appended if the five-minute ambient temperature is greater than 36 degrees F.

If an OBS is signed on, the remark PWINO shall not be generated.

When the precipitation identifier sensor is configured, enabled, and contains no data quality errors; the system shall remove PWINO from the remarks. If the FZRA sensor is configured, enabled, and has no data quality errors, the system shall remove the FZRANO remarks. Whenever the precipitation identifier data is restored, and the OBS is logged on, the system shall announce the restoration of the present weather identifier data by flashing the words: “PRECIP IDENT DATA AVAILABLE”, at the bottom of the one-minute screen for a period of 1 minute. The message “PRECIP IDENT DATA AVAILABLE” shall continue to be displayed in a constant intensity, high contrast color.

3.8.1.1.13.3.7. Whenever Report Processing is turned off for the freezing rain (FZRA) sensor or if the FZRANO sensor is reconfigured, the system shall examine the user status to see if an OBS is signed on:

If an OBS is not signed on, the system shall delete the automated FZRA remark and generate the remark FZRANO if the five-minute ambient temperature is less than or equal to 36 degrees F or is missing, until report processing is turned back on or the FZRA sensor is reconfigured. The remark FZRANO shall not be appended if the five-minute ambient temperature is greater than 36 degrees F. The words “FZRA DATA N/A” shall be flashed in a high contrast color for a period of 1 minute on the bottom of the one-minute screen. The message “ZE DATA N/A” shall continue to be displayed in a constant intensity, high contrast color, until report processing is turned back or the sensor is configured or enabled.

If an OBS is signed on the remark FZRANO shall not be generated.

When the FZRA sensor is configured, enabled, and contains no data quality errors, the system shall remove FZRANO from the remarks.

Whenever the FZRA sensor is restored, and the OBS is logged on, the system shall announce the restoration of the present weather identifier data by flashing the words: “FZRA DATA AVAILABLE”, on the bottom of the one-minute screen. The message “FZRA DATA AVAILABLE” shall continue to be displayed in a constant intensity, high contrast color.

3.8.1.1.13.3.8. Whenever the lightning sensor is reconfigured or disabled, the system shall examine the user status to see if an OBS is signed on:

If an OBS is not signed on, the system shall automatically generate the remark TSNO until lightning sensor is configured or enabled, and valid thunderstorm data is received from the sensor. The maintenance flag “$” shall not be generated for TSNO. The TSNO shall appear in the remark field on the one-minute page and in the METAR. The bottom of the one-minute screen shall display the words: “TSTM DATA N/A”. Note: Under no circumstance shall the present weather field of the METAR contain a “T” when a TSNO is present.

If an OBS is signed on the remark TSNO shall not be generated.

3.8.1.1.13.3.9. Whenever the lightning sensor is configured and enabled and lightning data is being received, the system shall remove “TSNO”. If the OBS is signed on, the system shall notify the user or restoration of the thunderstorm data by flashing the words: “TSTM DATA AVAILABLE” on the bottom of the one-minute screen on the OID, and sounding an audible alarm on the OID. The message “TSTM DATA AVAILABLE” shall continue to be displayed in a constant intensity, high contrast color.

3.8.1.1.13.3.10. The EDIT REMARKS page (EDIT-REM page) shall provide a manual toggle to selectively add or delete the TSNO, FZRANO, and PWINO remarks.