Emeritus Solutions Ltd

Delivering Ingenuity

In a Nutshell

Emeritus Solutions Ltd is a UK based Engineering Consultancy active in Underwater Acoustics, Navigation, Positioning, and all aspects of Digital Signal Processing from algorithms to implementations.

Emeritus Solutions Ltd competencies include:

  • Signal Processing, Navigation and Positioning, algorithms and analysis;
  • Embedded and Processing System Design using FPGAs, SOCs, DSPs, GPUs, PCs and microcontrollers;
  • Platform design using FPGAs, digital, analogue, PC, embedded computer and microcontroller hardware;
  • System implementation using C / C++, Delphi / Pascal, assembler and HDLs;
  • System Remediation and Consultancy.


Our two page shortform highlights selected capabilities and offerings, primarily our capabilities in the fields of underwater acoustics and navigation. Two of our computer instrumentation offerings are also showcased. Our soft SCSI technology which permits the real-time moitoring and exploitation of parallel SCSI disk traffic and data; for example, to provide non-intrusive verification of embedded system operation. Also, our Leech technology which permits the exploitation of the ASCII logs commonly used to store NMEA and sensor data on Linux systems. The Leech forwards data, in real-time, to (multiple) client compulters; for example, for additional processing. The beauty of the Leech technology is that its use is transparent to the Linux applications it leverages.

Acoustic Signal Acquisition and Recording

On the 28th of November 2013 we presented our paper All I Wanted was an Acoustic Recording ... at the 53rd Marine Measurement Forum at the National Oceanography Centre, Southampton; the abstract is reproduced below.

Hydrophones, used to receive acoustic signals, are probably the classic underwater sensor – what could be simpler ? However, when the signals click and the FFT spectrum surges, one might wish for something less troublesome than that simple ball hydrophone. This presentation will review the acoustic signal acquisition signal chain and comment on selected higher order design issues affecting the delivery of sweet signals from the receiver to the user. The technologies presented include ladder filters (1950’s), gyrators (1970’s), DSP, AOIP and 56 Henries of inductance in a PU moulding.

Navigation and Positioning

On the 29th of October 2008 we presented our paper Sharp Tools for Optimising Navigation Sensor Arrays at NAV 08 in London; the abstract is reproduced below.

For most navigators DOP is a given, and activities are tailored to it. However some navigators, who deploy sensor networks, “make their own DOP”. Undersea navigation is a domain in which this paradigm is increasingly important, similarly location services make every radio mast a navigation sensor. This increase in the volume of sensor network design requirements requires sharper tools, which can inform design decisions by less expert users. To do so, they must be better not only graphically but also in the metrics they present to inform the designer’s decisions.

Significant factors in sensor network design include: the required areal and vertical coverage, the quality of coverage required, system constraints (e.g. poor clock accuracy), the topography or bathymetry, and certainly at sea the propagation medium’s characteristics. Traditionally in designing sensor networks an expert navigator / surveyor has considered these explicit factors together with a substantial body of tacit knowledge, e.g. the often catastrophic reduction of position accuracy outside the sensor array. Beyond managing the data, tomorrow’s tools need to offer a sharper critique of performance than a washed out spatial DOP plot.

Plots of DOP are the de facto standard for the “quality” of a position fix. However, DOP values are only as valid as the assumptions which define the problem analysed. Questionable, common assumptions in undersea navigation include: precise knowledge of the propagation velocity and the absence of clock biases. DOP plots generally indicate modest degradation at the edge of sensor arrays. However, the practical navigator knows that without a fair measure of symmetry in the user – sensor geometry a fix is, in the absence of perfectly corrected measurements, very likely to be biased. The metrics used by tomorrow’s tools must address this limitation.

This paper will approach the sensor network synthesis problem from analytic and practical perspectives, propose metrics which we consider powerful compliments to DOP, and present comparative examples. The examples presented will range from the tutorial, through the underwater realm and European Loran coverage. The presentation will use graphical tools which permit the designer to work with tens of sensors and the constraints imposed by DTMs (digital terrain maps).

The VuGraphs are also available (as pdf) : Sharp Tools for Optimising Navigation Sensor Arrays - VuGraphs

On the 11th of June 2008 we presented our paper Predicting NavigationFix Accuracy : A Realistic Alternative to Over-Optimistic DOP Values at UDT 2008 in Glasgow; the abstract is reproduced below.

DOP (Dilution of Precision) “defines” how good a position fix is. If only it was so simple. Like too many statistical metrics, DOP depends more on the assumptions underpinning the analysis than on the data from which the fix is computed.

It is well known in the surveying community that symmetric geometries are highly beneficial where accurate, unbiased position solutions are desired. However, where symmetry is lacking, such as at the edge of a tracking range biased fixes are likely to result. Significantly, the usual DOP analysis and metrics do not identify this performance shortfall and are seriously flawed.

As tracking range deployments become more frequent, performance analysis techniques and tools are increasingly important to mission success. The limitations of the DOP paradigm and an alternative metric which encompasses intuition and is in operational use will be described with comparative examples presented.

The VuGraphs are also available (as pdf) : Predicting NavigationFix Accuracy : A Realistic Alternative to Over-Optimistic DOP Values - VuGraphs

PDP-8 on an FPGA : A Case Study in Obsolescence Management

Our PDP-8 on an FPGA implementation represents an exemplar both of our execution skills and of the innovative aproaches to customer problems, such as obsolescence management, we can offer.

Our paper PDP-8/E on an FPGA : A CaseStudy in Obsolescence presented at the Component Obsolescence Group (COG) quarterly meeting on 24 September 2008 focuses first on system and software obsolescence and on how this can be mitigated for both new and legacy software. Then, the feasibility of reimplementing the hardware elements of a system to preserve "the system in being" are demonstrated using the PDP-8 on an FPGA as an exemplar. The feasibility not only of re-implementing "any" computer system or digital logic, but also the potential for risk reduction provided by using JTAG to implement targeted, custom instrumentation within the design is demonstrated. And, of course, these JTAG based techniques are equally applicable to new systems and designs.

An earlier version of this paper PDP-8/E on an FPGA : A CaseStudy in Obsolescence which was presented at the MAE Show on 26 September 2006 additionally provides a broader review of obsolescence and a more detailed consideration of software obsolescence issues, before presenting the PDP-8 on an FPGA exemplar.

Additionally, selected references on Software Obsolescence are listed on the Obsolescence page

Core Competencies

Emeritus Solutions core competencies, based on the skills of Eur Ing Dr Martin Bishop and his associates, span the consultancy, engineering science, technology and implementation domains. Technical consultancy to effect troubleshooting, reviewing, architectural design, preparation of specifications, and independent verification and validation (IV&V) is available. Consulting assignments in engineering science can be performed on a broad range of topics, including: digital signal processing theory, navigation and positioning algorithms, communication algorithms, EMC and signal integrity, underwater acoustics analysis, and statistics and engineering mathematics. Technologies with which Emeritus Solutions can implement simple or complex systems include: digital signal processing, real time embedded computer systems, digital electronics using HDLs, FPGAs and SoCs, analog electronics, object oriented software for user interfaces and data analysis, and of course a broad range of EDA and productivity tools. Specimen applications to which Emeritus Solutions' expertise has been applied include: audio processing, GPS and radio navigation systems, telemetry systems, underwater acoustics calibration, trilateration tracking, and equipment design and development.