Nuclear magnetic resonance (NMR - the technology behind magnetic resonance imaging or MRI as used in medical scanning) offers enormous opportunity for materials detection and characterisation in the "real-world": that is open-access, electromagnetically unshielded applications outside of the laboratory where it is necessary to assess the quality, state or presence of materials. These applications include: the minimisation of delays to allow concrete to cure during construction or the assessment of building degradation in the built environment; managed forestry in order to decide which trees to fell or to minimise energy consumption from timber drying during processing; or illicit material detection at secure locations such as airports; and down bore-hole logging for oil and gas well exploration. However, save oil and gas exploration, where the earth's crust provides a natural electromagnetic shield, external radio frequency interference (RFI) pick-up restricts materials detection limits using affordable and practical light-weight, low-field strength magnets and hence inhibits the technology being taken up widely by industry. The problem is unwanted pick-up of radio signals such as aeronautical communications and amateur radio. The pick-up dominates and masks the weak NMR signals coming from materials to be inspected in open-access detectors. It is the purpose of this proposal to address RFI pick-up head on. We propose a new method to eliminate pick-up called active RFI suppression. We will build a technology demonstrator for active RFI suppression in an open-access NMR system. Our target is a greater than 10 times improvement in the signal-to-noise ratio, sufficient to enable take-up in construction, forestry and homeland security. The project takes advantage of recent rapid developments in real time signal processing and radio frequency engineering emanating from the mobile communications industry that enable modern devices to process radio signals in real time at the carrier frequency. With these advances we are able to measure the RFI pick-up independently of the NMR signal. Hence we can eliminate the pick up from the NMR signal. The team assembled for the project uniquely comprise experts in NMR techniques and applications and applied radio frequency electronic engineering. The project builds on an RFI characterisation and software feasibility study carried out jointly with Dstl during 2014 and our own experience of using NMR in construction and forestry both in the laboratory and outside in the "real-world" on construction sites and in forests. Dstl remain involved and contribute through support for an engineering doctorate research student, the provision of technical hardware on which to build the demonstrator and detailed knowledge of security applications.