Tests of reception of the combination of GPS and GLONASS signals under and above forest canopy in the Black Forest, Germany, using choke ring antennas

Blum, Ronny; Bischof, Rainer; Sauter, Udo Hans; Foeller, Joerg

doi:10.1080/14942119.2015.1122945

Cited by 8 publications

(7 citation statements)

References 9 publications

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“…However, there was little variation in values of HDOP in this study, where values ranged between 0.5 and 0.9 (Table 1, Figure 6). Values of HDOP may increase under canopy conditions (Blum et al 2016), and although the data were collected during final fellings, partial canopy coverage may have been present during collection of some of the data used in this study. Although we did not find a strong correlation between positional errors and the number of observed satellites, positional errors were limited to around 1.5 meter when only using measurements with at least 19 observed satellites.…”

Section: Discussionmentioning

confidence: 99%

Coupling a differential global navigation satellite system to a cut-to-length harvester operating system enables precise positioning of harvested trees

Noordermeer

Sørngård²,

Astrup

et al. 2021

International Journal of Forest Engineering

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Cut-to-length harvesters collect detailed information on the dimensions and characteristics of individual harvested trees. When equipped with global navigation satellite system (GNSS) receivers and motion sensors, the obtained measurements can be linked to locations of single harvested trees, benefitting a range of forest inventory applications. We propose a way of georeferencing harvested trees using a Komatsu 931XC harvester, which measures and records the machine's bearing, crane angle and crane length for each harvested tree. We replaced the harvester's standard GNSS receiver with a dual-antenna differential GNSS receiver. From the coordinates obtained, rotations calculated from the GNSS receiver and data on crane length, we determined the location of 285 trees harvested in eight final fellings in Norway. We compared the obtained locations to control measurements taken on the corresponding stumps directly after harvest using a differential GNSS receiver. The mean distance between planimetric coordinates of trees measured by the harvester and corresponding control measurements was 0.88 m with a standard deviation of 0.38 m. By correcting the crane lengths for systematic deviations between harvester and control locations, the mean distance was reduced to 0.79 m. This study shows that measurements of single harvested trees can be georeferenced with sub-meter accuracy, by mounting a differential GNSS receiver on a harvester and without installing additional sensors. The results also suggest that the positional accuracy can be further improved by measuring and recording the length of the telescopic boom, and that with minor adjustments, the system could be fully automated.

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Section: Discussionmentioning

confidence: 99%

Coupling a differential global navigation satellite system to a cut-to-length harvester operating system enables precise positioning of harvested trees

Noordermeer

Sørngård²,

Astrup

et al. 2021

International Journal of Forest Engineering

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“…The fused dataset contains noise resulting from the forest data, the machine data and the data fusion process. One relevant error source is the location recorded by the GNSS receiver, in particular when the forest canopy is blocking the satellite signal (Kaartinen et al 2015;Blum et al 2016). The resulting machine location is somewhat erratic, as can be seen in Fig.…”

Section: Discussionmentioning

confidence: 99%

Fusion of open forest data and machine fieldbus data for performance analysis of forest machines

Melander

Einola²,

Ritala

2019

Eur J Forest Res

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Forest resource data is important in targeting the forestry operations, and it is in the hearth of the precision forestry concept. The forest resource data can be produced with many techniques, and the number of existing forest data sources has increased during the years. In addition to the forest resource data, other data describing the circumstances of the forest site, such as trafficability and weather conditions, are available. In Finland, a forest data platform gathers the data sources under a single service for easier implementation of the precision forestry applications. This data is useful in operations planning, but it also describes the conditions that prevail when the forest machine arrives to the forest site. This study proposes data fusion between fieldbus time series of the forest machine and the forest data. The fused dataset enables explorative statistical analysis for examining the relationship between the machine performance and the forest attributes and provides data for building predictive models between the two. The presented methods are applied into a dataset generated from a field test data. The results show that some fieldbus time series features are predictable from forest attributes with R 2 value over 0.80, and clustering methods help in interpreting the machine behavior in different environments. In addition, an idea for generating a new forest data source to the forest data platform based on the fusion is discussed.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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“…If sub-meter accuracy is desired under canopies, similar to precision forestry applications that require accurate marking of skid trails or individual trees [35], ground based augmentation systems (GBAS) may be necessary. GBAS determine the degree of error and transmit corrections to rover units which can then re-calculate their positions accordingly [19].…”

Section: Discussionmentioning

confidence: 99%

Characterizing Rigging Crew Proximity to Hazards on Cable Logging Operations Using GNSS-RF: Effect of GNSS Positioning Error on Worker Safety Status

Wempe

Keefe

2017

Forests

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Logging continues to rank among the most lethal occupations in the United States. Though the hazards associated with fatalities are well-documented and safe distances from hazards is a common theme in safety education, positional relationships between workers and hazards have not been quantified previously. Using GNSS-RF (Global Navigation Satellite System-Radio Frequency) transponders that allow real-time monitoring of personnel, we collected positioning data for rigging crew workers and three common cable logging hazards: a log loader, skyline carriage, and snag. We summarized distances between all ground workers and each hazard on three active operations and estimated the proportion of time crew occupied higher-risk areas, as represented by geofences. We then assessed the extent to which positioning error associated with different stand conditions affected perceived worker safety status by applying error sampled in a separate, controlled field experiment to the operational data. Root mean squared error was estimated at 11.08 m in mature stands and 3.37 m in clearcuts. Simulated error expected for mature stands altered safety status in six of nine treatment combinations, whereas error expected for clearcuts affected only one. Our results show that canopy-associated GNSS error affects real-time geofence safety applications when using single-constellation American Global Positioning System transponders.

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Tests of reception of the combination of GPS and GLONASS signals under and above forest canopy in the Black Forest, Germany, using choke ring antennas

Cited by 8 publications

References 9 publications

Coupling a differential global navigation satellite system to a cut-to-length harvester operating system enables precise positioning of harvested trees

Coupling a differential global navigation satellite system to a cut-to-length harvester operating system enables precise positioning of harvested trees

Fusion of open forest data and machine fieldbus data for performance analysis of forest machines

Characterizing Rigging Crew Proximity to Hazards on Cable Logging Operations Using GNSS-RF: Effect of GNSS Positioning Error on Worker Safety Status

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