Crop Phenology Estimation Using a Multitemporal Model and a Kalman Filtering Strategy

In this letter, a new approach for crop phenology estimation with remote sensing is presented. The proposed methodology is aimed to exploit tools from a dynamical system context. From a temporal sequence of images, a geometrical model is derived, which allows us to translate this temporal domain into the estimation problem. The evolution model in state space is obtained through dimensional reduction by a principal component analysis, defining the state variables, of the observations. Then, estimation is achieved by combining the generated model with actual samples in an optimal way using a Kalman filter. As a proof of concept, an example with results obtained with this approach over rice fields by exploiting stacks of TerraSAR-X dual polarization images is shown.

Outsourcing and strategy in Spanish town halls: a field study

Purpose – This study seeks to analyse the links between strategies, structures and processes in the case of the largest Spanish town halls, using the Miles and Snow's models about organisational strategies, and asking the following questions: “What is the situation of municipal services' outsourcing in the largest Spanish town halls?”; “Do Spanish town halls follow the strategies suggested in Miles and Snow's model?”; and “Is there a relationship between the strategic position adopted by town halls and their stance on outsourcing?”. Design/methodology/approach – In order to achieve these aims a questionnaire was administered to the human resource managers in the town halls of the largest Spanish cities. Findings – The paper finds that outsourcing is a complement, which seeks to improve the services delivered, and local institutions do not resort to it due to a lack of internal resources but as a way to complement their own capabilities. Originality/value – The paper has identified three distinct strategic profiles in the town halls interviewed which coincide with the profiles that Miles and Snow call prospective, defensive and reactive strategies. It reveals that town halls which outsource to a greater extent are the ones which identify more with the prospective or reactive strategy, whereas those which outsource less are closer to the defensive strategy.