ResumoO Sensoriamento Remoto é a ferramenta que viabiliza o monitoramento das feições terrestre por meio de sensores a bordo de satélites, possibilitando uma análise holística e de baixo custo de grandes áreas da superfície terrestre. O presente trabalho analisou o comportamento espaço temporal no período de 1999 a 2019, de corpos hídricos, áreas irrigadas, vegetações e área urbana do município de Petrolina -Pernambuco, a partir do albedo e temperatura da superfície obtidos com dados orbitais dos satélites Landsat 5 e 8. Na análise comparativa dos dados, o albedo e a temperatura da superfície foram confrontados com a ocorrência dos dados pluviométricos e a classificação SCP (Semi-automatic Classificator Plugin) se mostrou uma ferramenta eficaz para a observação do desenvolvimento antrópico correspondente a urbanização. Os resultados evidenciaram que a temperatura da superfície apresentou em 2017, ano mais seco, valor máximo de 37ºC, e a ocorrência de pixels com temperaturas superiores a 30ºC foi observada em quase toda a área estudada; nos outros anos, foi factível observar o avanço das altas temperaturas da superfície de maneira menos abrangente. Em 2019, as maiores temperaturas da superfície concentraram-se nas áreas antropizadas que circundavam a malha urbana de Petrolina.

In remote areas, especially in the north-east of Brazil, small farmers have difficulty in accessing information and obtaining technical assistance on irrigation. The purpose of this paper is to develop a decision support system for irrigation water management via SMS, called IGmanejo, that offers information and irrigation advice on the farmer’s mobile phone. Simulations were performed to evaluate water savings based on current and historical data comparing the values obtained by FAO CropWat 8.0 software. The greater water savings observed in the cycle that began in the transition season showed a reduction of 26%. The proposed software showed that it is able to reduce water waste in agriculture and send simple and quality irrigation advice to remote areas with a technology already assimilated in rural areas, that is, the mobile phone.

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This research proposes a low-inclined orbit concept and design for the Internet-of-Things (IoT) using lean satellite standards in near-equatorial regions. The study aims to evaluate the coverage of various inclination angles at various latitudes and inclination angles in order to determine the most suitable satellite design for providing IoT coverage in these regions. The main methods applied in the study included analyzing the coverage performance of different inclination angles, the link budget analysis using simulations and the definition of the mission criteria. The results of the study show that the overall coverage performance decreases with an increase in the inclination angle. Satellites with lower inclination angles have ground tracks that are more closely aligned with the equator, while satellites with higher inclination angles have ground tracks that are inclined further toward the poles. In addition, the results show that the fraction of orbits with coverage (expressed as a percentage) declines with increasing latitude. Based on these findings, a low-inclined orbit of 24° provides the best coverage for IoT in near-equatorial regions within ±20 and 26° latitude, with a peak coverage of 27% at 24° latitude and a minimum coverage of 10% in the region spanning from 0° to ±27° latitude. This design offers more coverage time and a shorter revisit time to the selected regions for communication missions.

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