Analysis of concatenated waveforms and required STC

Abstract

In modern surveillance radar, pulse compression is applied to achieve long range coverage while maintaining both low transmit peak power and desired range resolution. When there is a requirement to increase the radarpsilas range without a corresponding increase in the transmitted peak power it is required that a longer uncompressed pulse be used. As a consequence the blind range, associated with blanking the receiver whilst transmitting the pulse, will increase and short range coverage will be lost. In this paper we initially present a system of concatenated waveforms that provide simultaneous radar coverage for both near and far ranges. The solution incorporates a combination of longer sub-pulses for far range and shorter sub-pulses for near range. Although the concatenated waveforms have a number of attractive attributes, they present a challenging problem in that different sub-pulses will reflect back from different ranges and be received at the same time. Therefore since each sub-pulse is not separable at the RF front end a more complex sensitivity time control (STC) is required. In the second part of this paper we analyze this phenomenon and propose a STC scheme to address the issue.