Maximizing Range Productivity

Mentoring

From time to time, you may experience the need for assistance in range operations to either adapt your current range for new test requirements or how to configure your instrumentation to make specific measurements. Whatever the need may be, NSI-MI Technologies can provide the assistance to ensure your productivity is optimized.

NSI-MI Technologies has a mentoring program that allows you to take full advantage of working alongside NSI-MI’s experienced and qualified engineers. This program utilizes hands on learning of best measurement practices while using your own range equipment. Topics covered may include best practices for basic range set up and instrumentation operation to measured data analysis. While on site, NSI-MI’s engineer will also be able to assess the range measurement efficiency and make recommendations on how to improve measurement performance.

Equipment

When faced with equipment challenges due to either changing test requirements, availability, or inoperability, NSI-MI Technologies can assist with ensuring that your range remain operational as much as possible. Whether faced with a short term need or a more permanent solution to replace outdated or unrepairable instrumentation, NSI-MI can provide the needed equipment.

NSI-MI maintains equipment inventory for most range applications and can provide the equipment on short notice. However, if you are aware of an aging product and its planned obsolescence, NSI-MI can provide a migration path to upgrade the equipment to the latest technology available. These programs are available to reduce your risk of downtime due to product availability or ability to repair. Whether needing a single piece of equipment on loan or complete replacement, NSI-MI can deliver to ensure your range remains operable.

Range Assessment

NSI-MI Technologies can also provide value added services to ensure your ranges are performing as expected or to assess their performance characteristics. Understanding a range’s capabilities avoids any uncertainty in performance when faced with changing test requirements. NSI-MI’s qualified engineering resources and range characterization equipment provides a qualitative assessment of your range’s performance.

In addition to evaluating an antenna’s properties for a given range configuration, NSI-MI can provide range alignment and accuracy measurement services as well. NSI-MI uses laser tracking technology for measuring the alignment of range components as well as measuring position accuracy.

NSI-MI's Chamber Accuracy Testing will help you insure your test range provides you with the optimum and documented performance for your antenna measurement facility. The method of accuracy testing will vary with your specific installation and complement of equipment. A common method of range accuracy testing is to use an NSI-MI Standard Gain Horn (SGH) and perform range pattern testing at two different distances separated by 1/4 wavelength, or on a spherical NF range by comparing 360phi sphere data to 180phi sphere data. The comparison of the results gives an estimate of the range reflection performance. In the image above, you can see the result of a complete range reflection test NSI-MI did on one of its test ranges over the full frequency range of 1 to 40 GHz.

NEAR-FIELD RANGE EVALUATION TESTING USING NIST 18 TERM ERROR MODEL

Any antenna range, near-field or far-field, is subject to error sources which must be carefully analyzed or evaluated. The near-field industry has adopted an evaluation technique based on a set of error terms first proposed by NIST (“Error Analysis Techniques for Planar Near-field Measurements”, IEEE Trans. Antenna and Prop. Vol. 36, no. 6, June 1988, by Allen Newell).

These 18 terms are typically evaluated by a combination of analysis and tests. NSI has extensive experience in performing complete range evaluations for gain, side lobes levels, cross-pol levels, and beam pointing errors. During system installation and training, we typically include a brief overview of the range evaluation process. A complete range accuracy evaluation including all testing, analysis, and summary report can be quoted as an optional service.

The following table shows an example of the results of the range evaluation on one of NSI’s large near-field ranges used for testing the Globalstar satellite antennas.

NSI-MI's 18-term error assessment will provide a detailed evaluation of your antenna range performance. Error assessment can be compiled for antenna gain, side lobe level (SLL) at different levels and cross-polarization accuracy. Each error assessment is only valid for a particular antenna at a particular frequency in a particular facility. Some items may be generalized, but most items in the error assessment cannot. The validation does therefore not extend to all frequencies for any antenna to be tested in that facility. The error assessment, therefore, does not extend to other frequencies or antennas tested in that facility.

Maintenance and Calibrations

Another method to consider for optimizing your range productivity is to maintain a rigorous maintenance and calibration program. NSI-MI maintains a staff of engineers that travel worldwide to perform various maintenance and calibration services on equipment. These services can be provided either on a contracted, periodic cycle or as-required basis.

NSI-MI Technologies also offers a software maintenance program to receive latest releases and updates to NSI-MI Technologies' software for your system, access to engineers for phone support, and discounts on system upgrades. Maintenance and calibration programs minimize the risk of downtime or out-of-calibration scenarios.