Software Defined DCF77 Receiver

This paper shows the solution of time stamp software defined receiver integration into low cost com-mercial devices. The receiver is based on a general pur-pose processor and its analog to digital converter. The amplified signal from a narrow-band antenna is connected to the converter and no complicated filtration has to be used. All signal processing is digitally provided by the processor. During signal reception, the processor stays available for its main tasks and signal processing con-sumes only a small part of its computational power

Efficient Spectral Power Estimation on an Arbitrary Frequency Scale

The Fast Fourier Transform is a very efficient algorithm for the Fourier spectrum estimation, but has the limitation of a linear frequency scale spectrum, which may not be suitable for every system. For example, audio and speech analysis needs a logarithmic frequency scale due to the characteristic of a human’s ear. The Fast Fourier Transform algorithms are not able to efficiently give the desired results and modified techniques have to be used in this case. In the following text a simple technique using the Goertzel algorithm allowing the evaluation of the power spectra on an arbitrary frequency scale will be introduced. Due to its simplicity the algorithm suffers from imperfections which will be discussed and partially solved in this paper. The implementation into real systems and the impact of quantization errors appeared to be critical and have to be dealt with in special cases. The simple method dealing with the quantization error will also be introduced. Finally, the proposed method will be compared to other methods based on its computational demands and its potential speed

Ecosystem Development in the Constructed Catchment “Chicken Creek”

Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances, or transgression of thresholds. We propose a conceptual framework of feedback processes in early states of ecosystem development affected by spatiotemporal environmental drivers. To test this concept, we used 10-year time series of hydrological, biological, geomorphological, and soil data from the constructed catchment Chicken Creek.” The 6ha site was left to unrestricted development since 2005 and was intensively monitored. The data showed a very rapid development of the site with an increasing complexity and heterogeneity. In the first years, stochastic signals like the initial substrate conditions and external drivers like extreme weather events were the most important factors resulting in abiotic/abiotic feedback mechanisms shaping the morphology of the site and creating site diversity. Initial abiotic feedback mechanisms between water and substrate were soon followed by abiotic/biotic feedbacks between biological soil crusts, invading vegetation, geomorphology, and hydrology resulting in state transitions of catchment functioning

Between biodiversity conservation and sustainable forest management - A multidisciplinary assessment of the emblematic Bialowieza Forest case

The tension between biodiversity conservation and multipurpose forest management may lead to conflicts. An internationally prominent example is the Bialowieza Forest Massif (BFM), an extensive forest complex with high levels of naturalness. We apply a systematic, multidisciplinary assessment process to review empirical evidence on different dimensions of the BFM conflict. While there is broad consensus that this forest massif is an exceptional place worth conserving and that a way forward is a zonation system combining conservation with management, exactly how this should be done has yet to be agreed upon. Our assessment shows that the key reasons for the BFM controversy go beyond the availability of knowledge on the ecological status of the BFM and include: 1) evidence stemming from different sources, which is often contradictory and prone to different interpretations; 2) knowledge gaps, particularly with regard to socio-economic drivers and beneficiaries as well as uncertainties about future trends; 3) fundamentally different values and priorities among stakeholder groups, resulting in power struggles, and an overall lack of trust. We conclude that evidence-based knowledge alone is insufficient to cope with complex conservation conflicts. While more evidence may help assess the consequences of decisions, the actual management decisions depend on different actors' worldviews, which are rooted in their professional identities and power, and their political and legal realities. This calls for conflict management through a well-organized participatory process organized and supervised by a body deemed legitimate by the groups involved