Diante da possibilidade da utilização da geotecnologia para a atualização de área construída dos imóveis urbanos, foi analisada a precisão de uma imagem aérea obtida por meio de um Veículo Aéreo não Tripulado (VANT) sem a utilização de pontos de controle, na medição de um imóvel. Para isto, utilizou-se diversas resoluções espaciais, de maneira a comparar, qual seria o erro de cada um deles. Alcançaram-se bons resultados com o pixel de 2, 5 e 10 cm, mas, um resultado inferior na resolução espacial de 20 cm, já que a última pode gerar algumas confusões.

Soybean is one of the main crop species grown in the world. However, there is a decline in productivity due to the various types of stress, including the nematodes Heterodera glycines and Pratylenchus brachyurus. The objectives were to determine the best spectral band for detecting H. glycines and P. brachyurus at the beginning of flowering (R1). Soil and root sampling was conducted at nine sampling sites in each of the five nematode-infested regions, totaling 45 sampling points. Flights were made at all regions using Phantom 4 Advanced, Sequoia and 14-band customized Sentera. For H. glycines, the red spectral band best explained the variability on soil and root nematode counts as well as the second stage of juveniles in soil. For P. brachyurus, Sentera RedEdge best explained the variability in root nematode counts and Sequoia NIR best explained soil juveniles. A multiple linear regression model using spectral data for detecting P. brachyurus and H. glycines improved R² compared to simple linear regressions. At flowering growth stage (R1), soybean spectral reflectance was associated with the number of H. glycines and P. brachyurus on soil and roots using low-cost and multispectral sensors.

Eficiência de distribuição do sistema de irrigação, por meio de um veículo aéreo não tripulado de baixo custo Efficiency of irrigation system distribution through a low-cost unmanned aerial vehicle

The change in the use of natural vegetation by annual or perennial crops, sugarcane and fast-growing forests causes changes in the biophysical variables, and these changes can be monitored by remote sensing. The objective of this work was to evaluate, on a temporal scale, the impacts of land use changes on biophysical variables in the county of Santa Helena de Goias-Goias/Brazil. Between the years of 2000 to 2015 areas were identified for agricultural crops 1 (annual crops), water, agricultural crops 2 (sugarcane), natural vegetation, pasture and urban areas. The MODIS (Moderate Resolution Spectroradiometer) sensor products were selected for study: MOD11A2-Surface temperature; MOD16A2-Real evapotranspiration, MOD13Q1-Enhanced Vegetation Index and rainfall data from TRMM (Tropical Rainfall Measuring Mission). The geographic coordinates referring to the land uses were inserted in the LAPIG platform, searching the information of the biophysical variables referring to the selected pixel. The impact of land use change was evaluated by calculating the weighted average through the quantitative classification of the areas. It is concluded for the period of study that the index of average vegetation of the county had increase. There was an increase in the evapotranspiration volume of the county from 28% from 2000 to 2013 and the average surface temperature of the county showed a reduction of 2 °C in the period from 2000 to 2015.

The measures of precipitation and evapotranspiration can be realized by means of meteorological predictors or by meteorological satellites. Both types have advantages and disadvantages. Emission is one of the most important climatic parameters for a region’s socioeconomic and environmental formation, while evapotranspiration is more important for global and local climate mediators. The objective of this work was to analyze the comparative form of the rainfall satellite data through the TRMM and evapotranspiration satellite, by the MODIS satellite, with surface data, that is, of meteorological demarcations, distributed in the State of Goiás, in the years of 2012 and 2013. The monthly measurements were taken in meteorological stations (automatic and conventional), distributed and representative in the State of Goiás. Data collection of the stations was done through the INMET website. The data of the TRMM satellite were obtained from the LAPIG-MAPS platform, developed by the Laboratory of Image Processing and Geoprocessing of the Federal University of Goiás (LAPIG/UFG), for the generation of the quarterly maps for the year 2012 and 2013. The high regression between the data of the surface meteorological stations and the data of TRMM satellite for the year of 2012 and 2013 allows to affirm a high reliability to the orbital data. The evapotranspiration data present low correlation between satellite data (MOD16) and surface stations. Still, this information evidences high potentiality and availability of information in large spatial and temporal scale.

No abstract

A agricultura digital, a aquisição e análise de informações remotas dos dados vem se tornando frequente com o uso dos Veículos Aéreos Não Tripulados (VANTs) e miniaturização dos sistemas de sensores. Com isto, esta pesquisa teve como objetivo, analisar o uso do sensoriamento remoto para a predição de variáveis agronômicas como diâmetro de caule, altura de planta e área de copa de goiabeiras, bem como para a diferenciação de alvos predominantes na área de estudo. Em função dos resultados, é possível com o sensoriamento remoto, determinar-se a área de copa, altura de planta e diâmetro de caule. Além disso o sensoriamento remoto permite a separação das plantas de goiabas, plantas daninhas, solo exposto, sombra de plantas e de palhada, selecionando de forma adequada as faixas espectrais ideias para a diferenciação de cada alvo.

To improve crop development, commercial substrates are recommended without distinction for different crops and/or varieties without considering their characteristics and needs; therefore, their composition and nutritional condition must be studied for each type of plant in its initial formation.The objective of this study was to evaluate the development of shoot and root systems of two lettuce cultivars produced in 10 different substrates. Great Lakes and Simpson Black Seed cultivars were evaluated in 10 substrates formulated by mixing a commercial substrate, organic compounds (swine, cattle, poultry) and sugarcane bagasse. Great Lakes cultivar had a higher development of the aerial part, whereas Simpson Black Seed cultivar had a more robust root system. The substrate with swine and poultry favored the development of the aerial part of the seedlings and lettuce, while the substrates with 33% of sugarcane bagasse improved the development of the root system. The commercial substrate used in isolation showed the lowest performance.