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Quantitative radar studies are an important component of studying the movements ofbirds. Whether a bird, at a certain distance from the radar, is detected or not dependson its size. The volume monitored by the radar is therefore different for birds of differentsizes. Consequently, an accurate quantification of bird movements recorded bysmall-scale radar requires an accurate determination of the monitored volume for theobjects in question, although this has tended to be ignored. Here, we demonstrate the importance of sensitivity settings for echo detection onthe estimated movement intensities of birds of different sizes. The amount of energyreflected from a bird and detected by the radar receiver (echo power) depends not only on the bird’s size and on the distance from the radar antenna, but also on the beamshape and the bird’s position within this beam. We propose a method to estimate thesize of a bird based on the wingbeat frequency, retrieved from the echo-signal, independentof the absolute echo power. The estimated bird-size allows calculation of sizespecificmonitored volumes, allowing accurate quantification of movement intensities.We further investigate the importance of applying size-specific monitored volumes toquantify avian movements instead of using echo counts. We also highlight the importance of accounting for size-specific monitored volumeof small scale radar systems, and the necessity of reporting technical information onradar parameters. Applying this framework will increase the quality and validity ofquantitative radar monitoring.

This paper presents a single antenna radar sensor with Ku-band radar transceiver IC realized in 0.13 μm CMOS processes. In the radar receiver, a sensitivity time control using a DC offset cancellation feedback loop is employed for constant SNR irrelevant on the distance. To reduce the direct coupled Tx signal to Rx in single antenna radar, stub tuned hybrid coupler is adopted instead of circulator. The measured distance is 8.2 m with horn antenna and metal plate target.

This paper presents a single antenna radar sensor with Ku-band radar transceiver IC realized in 0.13 μm CMOS processes. In the radar receiver, a sensitivity time control using a DC offset cancellation feedback loop is employed for constant SNR irrelevant on the distance. To reduce the direct coupled Tx signal to Rx in single antenna radar, stub tuned hybrid coupler is adopted instead of circulator. The measured distance is 8.2 m with horn antenna and metal plate target.

Sea clutter is interference background in radar target processing. It is difficult to detect long-range weak target in sea clutter. Sea clutter signal changes complex, with high intensity. For close signal, radar receiver will overload and reach saturation point. We are interested in the most dynamic range for displaying target echo and fast changing component of clutter. By analyzing spatial and temporal correlation of sea clutter, slow changing component can be minus from sea clutter. The innovation of this paper is to propose a linear prediction error method for sea clutter to increase dynamic range of radar receiver. It prevents overloading and reaching saturation point at close range.

Paper presents a Ku-band FMCW radar transceiver IC realized in 0.13 pm CMOS processes. In the radar receiver, a sensitivity time control using a DC offset cancellation feedback loop is employed, which preserves the receiver's SNR not depending on the distance. The radar receiver achieves the full chain gain of 82 dB, P1dB of −2.0 dBm at the minimum gain, and noise figure of 7.9 dB with 106 dB dynamic range. The measured result of the radar transmitter reveals 9 dBm output power. The radar transceiver consumes 115 mA from a 1.2-V power supply. With the aid of an external PLL, the Ku-band FMCW radar module is implemented and verified radar function by measuring the distance of various objects.

The effect of ship navigation radar signal processing has a great impact on the overall performance of the radar system. In this paper, the signal processing algorithm is studied. Firstly, the principle of radar azimuth and distance monitoring is introduced, then the pulse accumulation algorithm and median filtering algorithm are analyzed, and finally a sea clutter suppression algorithm based on sensitivity time control (STC) and a rain and snow clutter suppression algorithm based on constant false alarm rate are designed to improve the target monitoring performance of radar. In the test of the algorithm, the radar signal processing algorithm designed in this study has good precision as monitoring error of the target's azimuth and distance is controlled within 1%; and it also has a better suppression effect of sea clutter and rain and snow clutter, which can suppress the clutter well, improve the target clarity, and ensure the safe navigation of the ship. The experiment proves the effectiveness of the proposed algorithm and provides some theoretical basis for the better processing of radar signals, which is beneficial to improve the environment perception ability of ships in harsh environments and promote the further development of the navigation industry.

In order to solve the problem that the echo dynamic range is far greater than the range of the linear amplifier, this paper presents a short-range dynamic laser echo ranging approach. This method could generate wave by the FPGA and high speed DAC circuit, and then the STC (sensitivity time control) circuit could weaken the influence of the large echo dynamic range. Theoretical calculation and experimental results show that this scheme can be used for short-range laser radar echo processing, which not only can extend the distance of the dynamic range, but also can improve accuracy ranging. This method would be widely used in short-range laser radar systems.

We developed an underwater three-dimensional (3-D) imaging sensor using a 532-nm laser. The sensor system combines a dome lens with coaxial optics to realize a wide-scanning angle of 120 deg (horizontal)×30 deg (vertical) while having a compact size of 25-cm diameter and 60-cm length. A detector sensitivity time control circuit and a time-to-digital converter are used to detect a small signal and suppress the unwanted backscattered signals due to marine snow. 3-D imaging of the seafloor with 20-m width and 60-m length was demonstrated in the sea around Ishigaki Island, Japan.