SOW__PositioningSystem_TBedit.docx

STATEMENT OF WORK

FOR

COMPACT RANGE POSITIONING SYSTEM

INTRODUCTION

The Naval Research Laboratory’s (NRL’s) Radar Division maintains and operates an Antenna/Radar Cross Section (RCS) Measurement Facility suitable for:

· characterizing radiation and impedance properties of antenna systems,

· performing radar cross-section (RCS) measurements,

· measuring the s-parameters of radio frequency (RF)-system components, and

· determining reflection/transmission properties of radomes and other dielectric materials.

The facility offers compact range (antenna and RCS), near-field (planar and cylindrical), and far-field measurement options. Availability of multiple measurement techniques allows for comprehensive characterization of complex antenna systems including scattering matrix measurements, volumetric pattern analysis, 2D radiation pattern cuts, RCS determination, and isolation measurement. In order to support wide-ranging measurement techniques, a complex multi-axis positioning system is required.

The Measurement Facility currently consists of three (3) main sub-facilities; the Compact Range, the Anechoic Chamber and the Small Near-Field Scanner. The capability, equipment, and pertinent hardware for each sub-facility is tabulated below, in Table 1: List of Existing Hardware and Software, in Measurement Facility. This purchase will replace the following five (5) items in the Compact Range Facility:

· Slide Axis

· Azimuth Pedestal

· Roll/Elevation Head

· Feed Positioner

· Positioner Controller (Contact Range Axes)

The items are being replaced due to obsolescence issues that have resulted in degraded/insufficient performance

All replacement hardware shall maintain compatibility with the Compact Range Facility’s Near-Field Scanner (see item (6), in Table 1, below) to maintain seamless operation of planar and cylindrical near-field scanning. This includes the ability to operate, in conjunction with the Compact Range Facility’s Positioner Controller (Near-Field Scanner Axes) (see item (7) in Table 1, below), without modification to item (7) or item (6).

The software items (23)-(25) control all data acquisition equipment, control positioner controllers, and perform all required data processing. The same software packages are utilized in all three (3) measurement systems, which allows seamless transition of equipment among systems, when necessary, while requiring expertise in only a single software package. Consequently, any hardware acquisition to replace items (1)-(5) must be capable of being controlled by the software in (23)-(25) OR include software that can provide this capability to control all three (3) measurement systems. A more detailed description of each required component/subcomponent is provided in following sections.

TABLE 1: LIST OF EXISTING HARDWARE AND SOFTWARE IN MEASUREMENT FACILITY

BACKGROUND

The Radar Division Antenna and RCS Measurement Facility supports many programs from within the division, as well as many from other divisions (including Remote Sensing, Optical Sciences, and Tactical Electronic Warfare (TEW)) within NRL and organizations outside of NRL. The measurement facility is intended to provide full characterization of Navy systems by providing antenna pattern measurements and radar cross-section measurements. In recent years, the frequency range of many modern Navy systems is increasing to respond to threats with stressing requirements due to increased frequency range (extending into millimeter wave) and polarization purity.

The Radar Division currently has position system which it utilizes to perform its measurement functions. However, the existing positioning system remains from the original chamber installation and is nearing end of life which means that it has many components that are obsolete and does not provide sufficient accuracy for evolving system requirements. Previous acquisitions have upgraded the RF equipment, near-field measurement system, and the absorber treatments in the measurement facility to support high frequency measurements. However, some of the upgrades were not accurate enough to handle high frequency systems and the performance of the compact range mechanical positioning system was not upgraded to allow for these aforementioned RF systems enhancements to be fully utilized. Accurate characterization of the radiation pattern and polarization for these RF systems requires positioning accuracy not achievable with current hardware. The existing positioning system lacks the accuracy on the azimuth, elevation, and roll axes to repeatedly position antennas with narrow beamwidths, and feed axes that control the illumination of the compact range reflector lacks the accuracy for precise polarization alignment and the z-axis required for optimizing the illumination at high frequencies. This acquisition would replace the existing positioning system with one providing sufficient accuracy and repeatability.

The current positioning system is utilized for four (4) antenna and RCS measurement systems: compact range antenna measurements, compact range RCS measurements, planar near-field measurements, and cylindrical near-field measurements. The Antenna and RCS Measurement Facility utilizes the Orbit/Flam & Russell, Inc. (FR) 959 Data Acquisition Software by Microwave Vision Group (MVG) to control all four (4) of these modalities as it contains software drivers to control all existing positioning and measurement hardware. In order to preserve all current capabilities, any upgraded positioning system must either function seamlessly with the Orbit/FR 959 capabilities or include new software that replaces all existing capabilities.

OBJECTIVE

Currently, there are no compact ranges, at NRL, capable of providing the positioning accuracy and polarization purity required for these kind of measurements. In order to characterize these systems, the measurements currently must be performed at a facility outside of NRL. This acquisition would provide the Radar Division the ability to perform these measurements, on-site, and thus be of immediate benefit to users lab-wide. This will result in a more efficient resource saving time and reducing overall associated cost.

SCOPE

The contractor shall deliver a turnkey compact range positioning system that adheres to the requirements below.

HARDWARE REQUIREMENTS

The contractor shall provide the required hardware components of the Compact Range Positioning System listed below, consistent with items (1)-(5) in Table 1. This list includes some additional items, including an offset slide axis, model tower, cabling, and RF absorber treatments. These items are required to place antenna targets over the center of rotation at the center of the quiet zone, control all axes within the chamber, and maintain RF performance within the measurement facility.

MOTORIZED FLOOR SLIDE

The contractor shall deliver and install one (1) motorized floor slide. The floor slide shall provide approximately eight (8) feet of travel to allow positioning targets as far forward as the overhead crane and as far backwards as the nearfield scanner.

AZIMUTH POSITIONER

The contractor shall deliver and install one (1) heavy-duty azimuth positioner. The contractor shall install the azimuth positioner directly onto the slide axis. The azimuth positioner shall provide 360 degrees of travel and support a vertical load of at least 20,000 pounds.

OFFSET SLIDE AXIS

The contractor shall deliver and install one (1) offset slide axis that will be mounted in between the azimuth positioner and a model tower. This offset slide axis can be manual, but shall allow for multiple locations to be assigned to keep device under test (DUT) directly over the center of rotation of the lower azimuth positioner.

MODEL TOWER

The contractor shall deliver and install one (1) model tower. The model tower must be at a height to hold a target/DUT under test in the vertical center of the quiet zone – nominally, 108 inches off the floor.

ANTENNA/TEST POSITIONERS

The contractor shall deliver and install two (2) separate positioners that can be mounted on top of the model tower. These positioners shall be (1) a light duty roll over elevation and (2) a medium duty azimuth over elevation positioner. Both positioners shall be removable to provide flexibility in test configurations.

POSITIONER CONTROLLER

The contractor shall deliver and install positioner controller that enables software controlled motion of all new positioner axes (floor slide, azimuth positioner, antenna/test positioners, and feed positioner). The existing Orbit FR AL-4164-1 must remain to operate the 17’ x 17’ near-field scanner without modification. The Antenna and RCS Measurement Facility uses 959 data-acquisition software developed by Orbit/FR/MVG. Consequently, software drivers shall exist for all positioner controllers to facilitate seamless integration into the existing system.

LOCAL CONTROL UNITS (LCUS)

The contractor shall deliver and install LCU(s) (quantity as needed) with the positioner controllers for manual control of all axes within chamber.

FEED POSITIONING SYSTEM

The contractor shall deliver and install one (1) feed positioning system. The feed positioning system shall hold/control feed antennas located at the focal point of the offset-fed corrugated reflector of the compact range measurement system. The positioning system shall allow three-dimensional (3D) movement of the feed antenna as well as rotation about the polarization axis of the system. There shall also be an interface to standard flange arrangements for existing compact range feeds.

CABLING

The contractor shall provide cable carries (quantity as needed) and - where applicable - rotary joints (quantity as needed).

RF ABSORBER TREATMENTS

The contractor shall deliver and install RF absorber treatments on all positioning equipment installed in the compact range to help minimize reflections. Designs must be coordinated with the Radar Division Installation Representative and Contracting Officer’s Representative (COR) assigned to the project before install.

SOFTWARE REQUIREMENTS

The contractor shall successfully integrate all equipment into the NRL Antenna and RCS Measurement Facility.

The Compact Range Positioning System Components shall be compatible with existing compact range data acquisition/control software and existing near-field measurement hardware. As a result, all axes shall be controllable by the Orbit/FR 959 data acquisition software as well as by a LCU. The contractor shall deliver all drivers required for accurate automated motion control from within the Orbit/FR 959 Data Acquisition Software. Those components are described below.

EXISTING DATA ACQUISITION SOFTWARE:

· Orbit/FR 959 Data Acquisition Software

EXISTING NEAR-FIELD MEASUREMENT SYSTEM:

· Orbit/FR AL-49520-18-17.7-V

· Vertical near-field scanner from MVG

· Controller: AL-4164

CAPABILITIES:

· Compact range antenna pattern measurements

· Gated CW compact range RCS measurements

· Cylindrical near-field measurements

· Planar near-field measurements

· Cylindrical near-field transform

· Planar near-field transform

· Synchronized control of all positioning Equipment (including near-field scanner)

Any software delivered shall either interface with existing range equipment or all applicable equipment must be replaced with new systems that have the same characteristics and performance of the existing equipment to ensure successful software integration and to preserve all existing measurement capabilities as outlined in this statement of work.

All software provided shall preserve all current measurement modalities including compact range antenna pattern measurement, compact range gated continuous wave (CW) RCS measurements, planar near-field measurements, and cylindrical near-field measurements.

OTHER REQUIREMENTS

CABLE MANAGEMENT PLAN: The contractor shall provide a cable management plan that provides cable carries, rotary joints, and any additional hardware required to protect all positioner control cables and existing RF cables from damage under movement.

FIELD PROBING: The contractor shall perform a detailed field probing at the conclusion of the installation to ensure measurement capabilities have not been degraded and to prove that the feed positioning system has positioned all feeding antennas at the focal point of the existing compact range reflector.

SYSTEM ENGINEERING AND ANALYSIS: The contractor shall perform necessary systems integration and analysis to confirm that the operation of all positioning equipment enables operation of all existing measurement modes. The contractor shall ensure that the feed positioner placement locates feed antennas at the focal point of the existing compact range reflector.

WARRANTY: A warranty of at least one (1) year from the time of installation shall be provided on all hardware to protect against product malfunctions and defects.

MAINTENANCE AND SUPPORT: The vendor shall prepare a maintenance and support contract for software/hardware that enables the availability of necessary expertise to troubleshoot, upgrade, and maintain all provided hardware and software.

ON-SITE REQUIREMENTS: The contractor shall comply with the requirements for on-site contractors, as outlined in Attachment 2 – Requirements for On-Site Contractors.

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