o achieve this vision, we will address major global research challenges towards the establishment of the "quantum internet" —?globally interlinked quantum networks which connect quantum nodes via quantum channels co-existing with classical telecom networks. These research challenges include: low-noise quantum memories with long storage time; connecting quantum processors at all distance scales; long-haul and high-rate quantum communication links; large-scale entanglement networks with agile routing capabilities compatible with - and embedded in - classical telecommunicatons networks; cost-effective scalability, standardisation, verification and certification. By delivering technologies and techniques to our industrial innovation partners, the IQN Hub will enable UK academia, national laboratories, industry, and end-users to be at the forefront of the quantum networking revolution. The Hub will utilise experience in the use of photonic entanglement for quantum key distribution (QKD) alongside state-of-the art quantum memory research from existing EPSRC Quantum Technology Hubs and other projects to form a formidable consortium tackling the identified challenges. We will research critical component technology, which will underpin the future national supply chain, and we will make steps towards global QKD and the intercontinental distribution of entanglement via satellites. This will utilise the Hub Network's in-orbit demonstrator due to be launched in late 2024, as well as collaboration with upcoming international missions. With the National Quantum Computing Centre (NQCC), we will explore applications towards quantum advantage demonstrations such as secure access to the quantum cloud, achievable only through entanglement networks. Hub partner National Physical Laboratory (NPL) working with our academic partners and the National Cyber Security Centre (NCSC) will ensure that our efforts are compatible with emerging quantum regulatory standards and post-quantum cybersecurity to bolster national security. We will foster synergies with competing international efforts through healthy exchange with our global partners. The Hub's strong industrial partner base will facilitate knowledge exchange and new venture creation. Achieving the IQN Hub's vision will provide a secure distributed and entanglement-enabled quantum communication infrastructure for UK end-users. Industry, government stakeholders and the public will be able to secure data in transit, in storage and in computation, exploiting unique quantum resources and functionalities. We will use a hybrid approach with existing classical cyber-security standards, including novel emerging post-quantum algorithms as well as hardware security modules. We will showcase our ambition with target use-cases that have emerged as barriers for industry, after years of investigation within the current EPSRC QT Hubs as well as other international efforts. These barriers include security and integrity of: (1) device authentication, identification, attestation, verification; (2) distributed and cloud computing; (3) detection, measurement, sensing, synchronisation. We will demonstrate novel applications as well as identify novel figures of merit (such as resilience, accuracy, sustainability, communication complexity, cost, integrity, etc.) beyond security enhancement alone to ensure the national quantum entanglement network can be fully exploited by our stakeholders and our technology can be rapidly translated into a commercial setting.

Measuring the volume and structure of a tree accurately allows us to calculate the total above-ground carbon (C) stored in the tree, a very important property. Trees remove CO2 from the atmosphere during photosynthesis and can store this C for decades or even centuries until the tree dies, when some of it is released back to the atmosphere through decomposition. Tropical forests store around half of all above-ground terrestrial C, but are at particular risk due to deforestation and degradation, as well as from changing rainfall and temperature patterns. Surprisingly, our knowledge of tropical forest C stocks is quite poor, and errors in these stocks are large and uncertain. This uncertainty feeds into estimates of CO2 emissions due to deforestation, degradation and land use change. We will address this major uncertainty in the terrestrial C cycle by deploying a new, NERC-funded terrestrial laser scanner (TLS) to scan 1000s of trees in tropical forests on three continents: Amazonia, the Congo Basin and SE Asia. The laser data will allow us to measure 3D tree volume and biomass non-destructively to within a few percent of the best current estimates, made by destructive harvesting and weighing. The current, large uncertainties arise because weighing a tree is extremely difficult: tropical trees may be over 50m tall, and weigh 100 tonnes or more. Harvesting also precludes revisiting trees over time to measure change. In practice, a small sample of trees that have been harvested and weighed are related to easy-to-measure parameters of diameter and height, using empirical 'allometric' (size-to-mass) relationships. These relationships are then used to translate diameter and height measurements made over wider areas into estimates of biomass. Allometry is also the only way to infer biomass at very large (pan-tropical) scales, from remote sensing measurements. Unfortunately, the sample of harvested trees underpinning global allometric relationships is geographically limited, and contains very few large trees. Current estimates of tropical forest C stocks from satellite and ground data, all based on these very limited allometry samples, diverge significantly in size and pattern, leading to heated debate as to why this should be. We hope to settle this debate, given that our lidar-derived estimates of biomass are completely independent of allometry and unbiased in terms of tree size. We will 'weigh' more trees than are currently included in all global pan-tropical allometries and quantify uncertainty in the allometry models. We will also test assumptions made in allometric models regarding tree shape and wood density. Our measurements will also answer fundamental questions about geographical differences in structural characteristics across tropical forests. Our data will be vital for testing new estimates of biomass from remote sensing; the UK-led ESA BIOMASS RADAR and NASA GEDI laser missions will both estimate pan-tropical C stocks by relying on allometric relationships between forest height and biomass. Our work will feed into these two missions through long-standing collaborations with the lead scientists. More generally, the large number of tree measurements we will collect would be of great interest to researchers in tropical ecology, forestry, biodiversity, remote sensing and C mapping, among others. A key aim of the project is to ensure the widest use of our results, by making our data and tools publicly available. We will work with partners to explore routes for commercial developments and input into government policy, particularly relating to forest management and C mapping and mitigation. Lastly, we will make our work accessible through a range of outreach activities, including developing links between a school in the Amazon and UK schools, to raise awareness of scientific, conservation and policy issues surrounding tropical forests.

CASCADE will be a keystone in the current aerial robotics revolution. This programme will reach across a wide range of applications from fundamental earth science through to industry applications in construction, security, transport and information. There is a chasm between consumer level civilian drone operations and high cost military applications. CASCADE will realise a step change in aerial robotics capability and operations. We will be driven by science and industry problems in order to target fundamental research in five key areas; Integration, Safety, Autonomy, Agility, Capability and Scalability as well as overall project methodology. In targeting these six areas, CASCADE will free up current constraints on UAV operations, providing case study data, exemplars, guidance for regulation purposes and motivating links across the science and engineering divide. The landscape of aerial robotics is changing rapidly and CASCADE will allow the UK to be at the forefront of this revolution. This rapid change is reflected by the wide range of terminology used to describe aerial robots including; Drones, Unmanned Aerial Vehicles, Remotely Piloted Aerial Systems, and Small Unmanned Aircraft Systems (SUAS). Supporting technologies driving the aerial robotics revolution include improved battery technologies, actuators, sensors, computing and regulations. These have all significantly expanded the possibilities offered by smart, robust, adaptable, affordable, agile and reliable aerial robotic systems. There are many environmental challenges facing mankind where aerial robots can be of significant value. Scientists currently use resource intensive research ships and aircraft to study the oceans and the atmosphere. CASCADE will focus on reducing these costs and at the same time increasing capability. Some mission types involve prohibitive risks, such as volcano plume sampling and flight in extreme weather conditions. CASCADE will focus on managing these risks for unmanned systems, operating in conditions where it is not possible to operate manned vehicles. Similarly, there are many potentially useful commercial applications such as parcel delivery, search and rescue, farming, inspection, property maintenance, where aerial robots can offer considerable cost and capability benefits when compared to manned alternatives. CASCADE will focus on bringing autonomous aerial capabilities to a range of industry applications. For both scientific and industry purposes, CASCADE will consider a range of vehicle configurations from standard rotary and fixed wing through to hybrid and multi modal operations. These will bring unique capabilities to challenging operations for which there is no conventional solution. At present, because of concerns over safety, there are strict regulations concerning where and how aerial robots can be operated. Permissions for use are granted by the UK Civil Aviation Authority and operations are generally not permitted beyond line of sight, close to infrastructure or large groups of people, or more than 400 feet from the ground. These regulations currently restrict many of the potentially useful applications for aerial robots. CASCADE aims to undertake research into key underpinning technologies that will allow these to be extended or removed by working with regulating authorities to help shape the operating environment for future robotic systems. CASCADE will prove fundamental research through a wide variety of realistic CASE studies. These will be undertaken with academic and industry partners, focussing on demonstrating key technologies and concepts. These test missions will undertake a wide range of exciting applications including very high altitude flights, aerial robots that can also swim, swarms of sensor craft flying into storms, volcanic plumes and urban flights. Through these CASCADE will provide underpinning research, enable and educate users and widely support the aerial robotics revolution.

This Hub accelerates progress towards a new "quantum era" by engineering small, high precision quantum systems, and linking them into a network to create the world's first truly scalable quantum computing engine. This new computing platform will harness quantum effects to achieve tasks that are currently impossible. The Hub is an Oxford-led alliance of nine universities with complementary expertise in quantum technologies including Bath, Cambridge, Edinburgh, Leeds, Strathclyde, Southampton, Sussex and Warwick. We have assembled a network of more than 25 companies (Lockheed-Martin, Raytheon BBN, Google, AMEX), government labs (NPL, DSTL, NIST) and SMEs (PureLiFi, Rohde & Schwarz, Aspen) who are investing resources and manpower. Our ambitious flagship goal is the Q20:20 engine - a network of twenty optically-linked ion-trap processors each containing twenty quantum bits (qubits). This 400 qubit machine will be vastly more powerful than anything that has been achieved to date, but recent progress on three fronts makes it a feasible goal. First, Oxford researchers recently discovered a way to build a quantum computer from precisely-controlled qubits linked with low precision by photons (particles of light). Second, Oxford's ion-trap researchers recently achieved a new world record for precision qubit control with 99.9999% accuracy. Third, we recently showed how to control photonic interference inside small silica chips. We now have an exciting opportunity to combine these advances to create a light-matter hybrid network computer that gets the 'best of both worlds' and overcomes long-standing impracticalities like the ever increasing complexity of matter-only systems, or the immense resource requirements of purely photonic approaches. Engineers and scientists with the hub will work with other hubs and partners from across the globe to achieve this. At present proof-of-principle experiments exist in the lab, and the 'grand challenge' is to develop compact manufacturable devices and components to build the Q20:20 engine (and to make it easy to build more). We have already identified more than 20 spin-offs from this work, ranging from hacker-proof communication systems and ultra-sensitive medical and military sensors to higher resolution imaging systems. Quantum ICT will bring great economic benefits and offer technical solutions to as yet unsolveable problems. Just as today's computers allow jet designers to test the aerodynamics of planes before they are built, a quantum computer will model the properties of materials before they've been made, or design a vital drug without the trial and error process. This is called digital quantum simulation. In fact many problems that are difficult using conventional computing can be enhanced with a 'quantum co-processor'. This is a hugely desirable capability, important across multiple areas of science and technology, so much so that even the prospect of limited quantum capabilities (e.g. D-Wave's device) has raised great excitement. The Q20:20 will be an early form of a verifiable quantum computer, the uncompromised universal machine that can ultimately perform any algorithm and scale to any size; the markets and impacts will be correspondingly far greater. In addition to computing there will be uses in secure communications, so that a 'trusted' internet becomes feasible, in sensing - so that we can measure to new levels of precision, and in new components - for instance new detectors that allow us to collect single photons. The hub will ultimately become a focus for an emerging quantum ICT industry, with trained scientists and engineers available to address the problems in industry and the wider world where quantum techniques will be bringing benefits. It will help form new companies, new markets, and grow the UK's knowledge economy.

There is growing interest in the UK space sector for communications, imaging and earth observation. Key to this is sending and receiving electromagnetic waves. To enable higher communication rates and get greater accuracy in imaging often higher frequencies are used. This project will develop new structures using microfabrication techniques to develop novel antennas and polarizers for satellites and the earth segment over frequencies from 28 GHz up to 1 THz. This frequency range overlaps and extends the currently used frequencies. ANISAT will address these five technical challenges: 1) Designing anisotropic metamaterials; 2) Exploiting these properties to design novel antennas, polarizers and RF devices; 3) Developing novel methods of measuring these properties; 4) Microfabricating heterogeneous anisotropic structures; 5) Combining these elements into a series of demonstrators. The above five points are addressed in more detail below: i) When an electromagnetic wave moves through a material it is slowed down by the dielectric properties. If an artificial dielectric can be composed of small (compared to a wavelength) rectangular or elliptical inclusions, then this composite material will behave differently when the incident electromagnetic wave has different polarizations. This can be exploited to create circularly polarized antennas where the electric field traces a circle in time. This is an advantageous property for space communications. ii) Currently, dielectric measurements only consider the dielectric properties for one polarization and effectively assume the materials are isotropic. ANISAT will develop a novel measurement system using resonant metasurfaces that can measure the properties along all three axes. This will open a new degree of freedom for antenna and radiofrequency engineers. iii) These anisotropic artificial dielectrics will be used to design novel circularly polarized antennas. It is currently challenging to feed antennas to create circular polarization at frequencies above 50 GHz due to the small scale of the feed structure. High gain multi beam cavity antennas and polarizers will be designed at a range of frequencies up to 1 THz. iv) Initial anisotropic artificial dielectrics will be fabricated using 3D-printing. This provides a simple and readily exploitable fabrication process. However, the upper frequency range is limited to approximately 40 GHz by the size of the small-scale air/metal inclusions inside the composite. Above this frequency the inclusions approach the scale of a wavelength and they become resonant. To extend the frequency range, novel microfabrication processes in clean rooms will be developed and exploited. These include fully metallised SU8 photoresist polymers and/or silicon layers with a high dimensional accuracy of the scale of a few microns. v) The learning process will be multidisciplinary and iterative as each stage innovates further advances. The close geographical proximity of the two universities will be highly beneficial in this regard. The plan is to create laboratory demonstrators that can be showcased to industry. These provisionally include: a novel dielectric measurement system; a high gain circularly polarized antenna at Ka band (26 - 40 GHz); a circularly polarized Fabry-Perot antennas at frequencies up to 110 GHz; and linear to circular polarizers and beam splitters from 220 - 300 GHz and at a central frequency of 640 GHz.