Error Assessments

Error Assessments

Our comprehensive Error Assessment services to ensure your test ranges consistently meet performance expectations. We product tailored assessments to provide valuable insights into your specific range's capabilities, crucial for adapting to evolving test requirements with confidence.

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Qualitative Range Performance Assessment

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).

Range Alignment and Accuracy Measurement

Beyond evaluating antenna properties, NSI-MI specializes in range alignment and accuracy measurement services. We employ state-of-the-art laser tracking technology to ensure precise alignment of range components and accurate position measurement.

Accuracy Testing Methods

Our error assessment methodologies are customized to your specific installation and equipment configuration. A common approach involves using NSI-MI Standard Gain Horns (SGH) for range pattern testing at varying distances. For instance, comparing range pattern data collected at two distances separated by 1/4 wavelength provides insights into range reflection performance.

Near-Field Range Evaluation Testing Using NIST 18 Term Error Model

Antenna ranges, whether near-field or far-field, are susceptible to error sources that require meticulous evaluation. NSI-MI adopts evaluation techniques based on the NIST 18 Term Error Model, established to analyze and mitigate potential errors in range measurements. We specialize in evaluating gain, side lobes levels, cross-pol levels, and beam pointing errors to ensure accurate and reliable test results. The table to the right is an example table showcasing the results of a range evaluation conducted on one of NSI-MI’s large near-field ranges, specifically used for testing Globalstar satellite antennas.

Comprehensive Range Evaluation Services

Our services extend to complete range accuracy evaluations, encompassing comprehensive testing, detailed analysis, and a comprehensive summary report. This optional service provides a thorough assessment of your range's performance across its operational spectrum.

Partner with NSI-MI Technologies to elevate the precision and reliability of your test ranges, ensuring consistent and accurate antenna measurements. Contact us today to discuss how our Error Assessment services can optimize your testing capabilities.


SAMPLE TEST DATA - RESULTS MAY VARY


Uncertainty (dB)
Beam-1 Co-po
Term Item Gain EIRP -10 -20 -30 -40 Source
1 Probe relative pattern 0.00 0.00 0.09 0.09 0.34 0.34
2 Probe polarization ratio 0.00 0.00 0.01 0.04 0.14 0.40
3 Probe gain 0.09 0.09 0.00 0.00 0.00 0.00 Does not affect relative measurements
4 Probe alignment 0.05 0.05 0.02 0.08 0.08 0.11
5 Normalization constant 0.05 0.10 0.00 0.00 0.00 0.00 Repeatability of connectors and accuracy of attenuators
6 Impedance mismatch 0.05 0.06 0.00 0.00 0.00 0.00 Assumes a -30 dB match at all locations
7 AUT alignment 0.00 0.00 0.00 0.00 0.00 0.00 Does not affect relative measurements
8 Data point spacing 0.03 0.03 0.09 0.28 0.88 2.80 Does not affect relative measurements
9 Measurement truncation 0.01 0.01 0.04 0.12 0.39 1.12
10 XY errors 0.00 0.00 0.00 0.01 0.04 0.11 Based on a measured X-Y RMS error of 0.13mm
11 Z errors 0.00 0.00 0.00 0.01 0.02 0.06 Based on a measured Z RMS error of 0.07mm
12 Probe-AUT reflections 0.06 0.06 0.09 0.27 0.86 2.70 Compares Alenia file Gtour63
13 Receiver linearity 0.02 0.02 0.06 0.19 0.60 1.90 Simulation with HP8530 linearity specs.
14 Systematic phase 0.00 0.00 0.01 0.02 0.05 0.20 Based oncable phase tests. Files: Cable_x1.dat, Cable_y2.dat.
15 Dynamic range 0.00 0.00 0.01 0.02 0.05 0.20 Measured 70 dB dynamic range
16 Room scattering 0.04 0.04 0.11 0.34 1.10 3.40 Based processing Gstar008 and comparing Z1Z3 vs. Z1aZ3a
17 Leakage and crosstalk 0.01 0.01 0.04 0.11 0.34 1.10
18 Random errors 0.00 0.00 0.00 0.00 0.00 0.00 This term is already included in item 16
19 RSS total 0.15 0.18 0.21 0.59 1.87 5.76

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.