Single point positioning (SPP) mode, related to pseudorange measurements, limits the level of accuracy to several meters in open sky and to several dozens of meters in urban canyons. This paper explores the effect of using a large number of SPP observations from low-cost global navigation system (GNSS) receivers, smartphones, and handheld GNSS units. Data segmentation and bootstrapping statistical methods were used to obtain the deviation, which can describe the accuracy of the large sample. The empirical test recording data showed that the error may achieve a sub-meter horizontal accuracy by the simple process of increasing the measurements of smartphones and handheld GNSS units. However, the drawback is the long period of time required. To reduce the satellite tracking time, a least squares solution network was applied over all the recorded data, assisted by the external geometric conditions. The final goal was to obtain the absolute positioning and associated deviations of one vertex from three or five GNSS receivers positioned on a network. The process was tested in three geodetic network examples. The results indicated that the enhanced SPP mode was able to improve its accuracy. Errors of several meters were reduced to values close to 50 cm in 25–37 min periods.

Mapping aboveground carbon density in tropical forests can support CO₂ emission monitoring and provide benefits for national resource management. Although LiDAR technology has been shown to be useful for assessing carbon density patterns, the accuracy and generality of calibrations of LiDAR-based aboveground carbon density (ACD) predictions with those obtained from field inventory techniques should be intensified in order to advance tropical forest carbon mapping. Here we present results from the application of a general ACD estimation model applied with small-footprint LiDAR data and field-based estimates of a 50-ha forest plot in Ecuador’s Yasuní National Park. Subplots used for calibration and validation of the general LiDAR equation were selected based on analysis of topographic position and spatial distribution of aboveground carbon stocks. The results showed that stratification of plot locations based on topography can improve the calibration and application of ACD estimation using airborne LiDAR (R² = 0.94, RMSE = 5.81 Mg·C·ha⁻¹, BIAS = 0.59). These results strongly suggest that a general LiDAR-based approach can be used for mapping aboveground carbon stocks in western lowland Amazonian forests.

Desde la Topografía hemos estado trabajando en obtener la modelización tridimensional de elementos arqueológicos haciendo uso de los sistemas láser escáner de corto, medio y largo alcance. Hemos efectuado el modelado de piezas arqueológicas para museos, levantamientos de yacimientos para equipos científicos y documentación general de áreas de interés cultural. En este artículo pretendemos exponer cómo habiendo llegado a un punto de vista lleno de escepticismo, en el que se podía pensar que la realidad virtual había encontrado un límite en la representación de la arqueología, se puede iniciar un nuevo camino. Proponemos una búsqueda de nuevos modos y procedimientos de análisis con la información recopilada, en definitiva de nuevos documentos para la interpretación científica de la arqueología que participen en la creación de conocimiento, desde las nubes de puntos adquiridas en campo. En este trabajo exploramos los documentos de análisis que son utilizados actualmente en el proceso de creación de modelos de realidad virtual e iniciamos la búsqueda de nuevos planteamientos.