spanner <img src="https://github.com/bi0m3trics/spanner/blob/master/img/spanner_hex_logo.png" width="150" align="right"/>

Definition of spanner <br/>1 (chiefly British): WRENCH <br/>2: a wrench that has a hole, projection, or hook at one or both ends of the head for engaging with a corresponding device on the object that is to be turned <br/>3: implements algorithms for terrestrial, mobile, and airborne lidar processing, tree detection, segmentation, and attribute estimation (Donager et al., 2021), and hierarchical patch delineation (Girvetz & Greco, 2007).

<img src="https://github.com/bi0m3trics/spanner/blob/master/img/tshirt3.png" width="100%" height="auto" align="center"/>

Install spanner

Get the latest released version of spanner from github.

remotes::install_github('bi0m3trics/spanner')

Workflows

Terrestrial Lidar Tree Attributes and Segmentation

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This package implements the tree detection and segmentation algorithm described in <a href="https://doi.org/10.3390/rs13122297">Donager et al. (2021)</a>. The algorithm estimates tree locations and DBH by rasterizing individual point cloud values of relative neighborhood density and verticality within a slice of the normalized point cloud around breast height (1.37 m), then performs individual tree (instance) segmentation following ecological principles for "growing" trees based on input locations in a graph-theory approach. Implementation relies on work of <a href = "https://doi.org/10.1016/j.rse.2020.112061">Roussel et al. (2020)</a>, <a href="https://doi.org/10.1016/j.isprsjprs.2015.10.007">Tao et al. (2015)</a>, and <a href="https://doi.org/10.1016/j.compag.2017.10.019">de Conto et al. (2017)</a>.<br/><br/>

Citation: Donager, Jonathon J., Andrew J. Sánchez Meador, and Ryan C. Blackburn 2021. Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare? Remote Sensing 13, no. 12: 2297. https://doi.org/10.3390/rs13122297

PatchMorph: Patch Delineation Algorithm

<img align="right" height="240" src="./img/pm_output.png">

The patchwoRk function implements a patch delineation algorithm [at present it only implements <a href="https://doi.org/10.1007/s10980-007-9104-8">'PatchMorph' (Girvetz & Greco 2007)</a>, which can delineate patches across a range of spatial scales based on three organism-specific thresholds - (1) land cover density threshold, (2) habitat gap maximum thickness (gap threshold), and (3) habitat patch minimum thickness (spur threshold)].

Citation: Girvetz EH, and Greco SE. 2007. How to define a patch: a spatial model for hierarchically delineating organism-specific habitat patches. Landscape Ecology 22: 1131-1142. http://dx.doi.org/10.1007/s10980-007-9104-8