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European Space Agency’s 2019 Living Planet Symposium, 13-17 May 2019, Milan, Italy, Monitoring ocean circulation at high resolution in both space and time is of paramount importance for understanding and modelling the ocean-atmosphere climate system, especially in coastal areas. Spaceborne radar altimeters have been used to successfully monitor ocean circulation on a global scale (>30km) in the deep ocean when the geostrophic approximation is generally valid. The ocean structures seen in high-resolution satellite measurements at meso (10-100km) and sub-mesoscale (, A dedicated system performance analysis tool has been implemented in order to derive all the instrument and obser-vation specifications to meet the requirements on the ocean surface observables. The key performances, which are driving the instrument are a measurement accuracy of 2D ocean surface motion of 5 cm/s (for velocities below 50cm/s and wind speed > 3m/s). The performance tool is based only on numerical models without assumptions and calculates the reflected power and the Doppler characteristic of each backscattering cell of the illuminated sea surface in dependency on the radar properties, the acquisition geometry, and the flight parameters. The performance of the instrument for the baseline design achieves a swath width larger than 2km in case of wind speed of 3m/s. The noise equivalent sigma zero (NESZ) is between -30dB and -45dB and the radiometric resolution is better than 0.1dB. The velocity accuracy that the system can obtain is fulfilled from look angles lower than 20 degrees up to look angles above 63 degrees, resulting in more than 3km of swath available. A functional test campaign over ocean is planned in summer 2019 in the Iroise Sea to verify the end-to-end functionality and performance of the fully integrated instrument, including internal calibration capabilities, and of the processor by means of on-ground testing and flight tests

The key issue in the design of a MRA antenna is the technique used to obtain the required phase shift in the field reradiated by different elements. In the past many solutions have been proposed. Stub loaded patches, patches of variable sizes and identical patches with variable rotation angles are the most popular techniques. A technique was introduced at IRCTR (International Research Centre for Telecommunications and Radar) which is based on patches with slot of different sizes. The slot changes the resonant frequency of each element of the array, which in turn gives a change in the phase of the reradiated field. The analysis was first carried out on a 32.5GHz single element and then extended to large arrays of finite dimensions, at the same frequency. Some of these arrays were manufactured and their performance measured. A waveguide simulator exploiting the concept of infinite array is successfully implemented in the characterization of reflected phase. A hollow patch antenna at Ka-band is encapsulated between two air-filled waveguide and its phase-frequency curve is measured. A comparison of the simulations using method of moment and the measurement results show a good agreement. The phase variation is in the range of +160° to -160° for a frequency sweep from 26 to 38GHz.

For the detection and tracking of a football on a playground, a transponder was developed on a flexible substrate suitable for integration in the ball. The transponder secures permanent detection and identification with FMCW radar, thus enabling an easy and cost-effective tracking of the ball. The transponder consists of a dipole antenna and a microprocessor controlled switch which shorts at a programmable rate the input port of the dipole. The user selectable switching frequency or switching sequence can be recognised in the radar Doppler spectrum, since the transponder’s received amplitude and phase vary between the on- and off-state. This approach is patented under nr. 07112606.4. The design, realisation and first results of the transponder are discussed in this article.