IEEE 1502-2020 pdf download

IEEE 1502-2020 pdf download.IEEE Recommended Practice for Radar Cross-Section Test Procedures.
4.2.4 Developing a standardized RCS measurement process
The remainder of this clause is devoted to laying out procedures and practices that make up a standardized RCS measurement system. The first requirement is to dciinc the RCS mcasuremcnt process. Key issucs arc the proper characterization of the range and its environment, the development of a range uncertainty budget, and an examination of the issues associated with calibrating the RCS measurernenls. Finally, an approach to implementing these standards is proided.
4.3 Standardized test procedures
4.3.1 Purpose
The development of standardized test procedures provides a framework for many components of the nscasLlren)ent process. linpoitant components of the measurement process that are to be standardized include the following:
– Data collection
Range calibration
— Post-processing
– Range characterization Range ernst budget
By developing standardized procedures for these and other components of the measurement process, several advantages can be realized. One important advantage is that the technical approach will be consistent from range to range, which means that users of the data know what to expect during the testing process. Preparation for additional measurements or follow.on tests is easier, and ii becomes significantly easier to make comparisons between ranges. This last point should not be minimized, This type of comparison is often desired. but usually it is not earned out because the procedural dificrences between ranges (even of the same type i arc sometimes considered too great to overcome.
Another advantage that will result from standardization is a minimization of error, especially human error. By developing and following standardized procedures, there is less chance of incorrect procedures being used. It also helps in the verification psocess if standard procedures are followed at different ranges. By using the same basic procedures in multiple ranges, the experience base for that type of procedure is increased, which leads to greater confidence that the procedure is robust and will produce the correct results under a variety of circumstances. Finally, by using standardized procedures. there is less chance that the application of a particular process will be called into question if there isa problem for legal challenge) with the results at a later date.
4.3.2 Approach
Since there arc several types of ranges and many examples of each type. it is important to organize the test procedures to cover the unique features of each possible range type while maintaining as much commonality in procedures between the different range types as possible.
One way of accomplishing this goal is to identify the essential features of cach range type and to decide which features arc common to other range types and to what degree. Arranging the different range types in a hierarchical structure has several advantages, For instance, any procedures that apply to ranges at the “top” of the structure (the most common range features) should also apply to those iowcr” in the structure I ranges with more specific features). This approach implies that test plans developed for higher levels can be specialized for lower kvcls, which keeps the procedures used common to many dilterent range types. This approach al%o minimizes the work required to develop test plans and facilitates comparisons among dificrent ranges.
5. Measurement techniques
5.1 General
IFEE Std 149 should be consulted for antenna measurement procedures. The purpose of the test range is to provide an environnient that simulates free-space. far-field conditions Mea.%urcmcnts of objects placed in these environments and obtained by precision instrumentation radar can yield accurate measures of their RCSs.
5.2 Outdoor ranges
5.2.1 Introduction
To approxitnate the desired free-space, far-field conditions in an outdoor environment, it is common to separate the source radar physically from the targets with “sufficient separation” in a measurement environment that is free of unnecessary monostanc and bistatic radar clutter. The approximation to a plane wave is obtained by the range length and the approximation to fi-ec space by the absence of spurious signals originating from clutter multipath that esenlually propagates to the desired test zone as an undesired interference term. The amplitude field taper in the test zone is determined by the radiation pattern of the instrumentation radar: the phase taper is determined by the distance between the radar and the test zone:
and the amplitude ripple is determined by interference with the direct signal caused by spurious reflections. In the special case of the ground plane range. which is described in 5.12, the amplitude taper in the vertical direction is aLso determined by the ground-bounce geometry. Given surrounding aucas that are free of obstacles, the principal source of contamination to the incident field is the reflection from the ground surface. Consequently, the control of signal rellections from the ground surface constitutes the principal design objective of the range.