Latest Contributions by JoeBanker

I'm having issues when projecting habitat suitability rasters (WGS84) to a projected coordinate system (Africa Albers Equal Area Conic). The reason I reproject the rasters is so that I can calculate the area of suitable habitat which is intended to be used for conservation-related purposes. Considering that I have about 900 individual rasters that need to be reprojected for area calculation purposes I decided to automate the process in R. However, I realised that there is a difference in 'cell size' values for the same rasters between R and ArcMap 10.7. For example, when I use 'Raster A' (cell size: X: 0.00833333376786619; Y:0.00833333376786619) and project it to Africa Albers Equal Area Conic the cell sizes are different between R and ArcMap and therefore also the area of suitable habitat... After reprojecting in ArcMap the cell size of the rasters are X: 879.789038737608                                                                                               Y: 879.789038737608          But in R the 'cell size' is different: X: 853                                                        Y: 902 The resampling method used was bilinear when reprojecting the raster. This turned out to be a massive headache to me because I do not know which area calculated is the correct one as both R and ArcMap provide area estimates vastly different from one another. Area calculated from R = 18000km2 and in ArcMap 14000km2. Any advice would be much appreciated. ... View more

I need to select a random subset of spatially independent grid cells for a species occupancy modelling study.  I defined my sampling units as 100x100m grid cells covering the entire study area. However, these grids are continuous and not independent from one another (see attached). I would like to select a random subset of grids (let's say 50%) which is at least 100m from the closest grid (between each grid cell there must be at least a 100m distance). Any advice on this will be much appreciated, also, I'm using ArcGis 10.6. ... View more

I have three transects on opposing slopes. Each transect has ibutton data loggers set to record temperature at hourly intervals. The loggers are spaced at 20m altitudinal intervals from 1550 - 1810m (west-facing slope) and 1550 - 1690m (east-facing slope). Each transect has three ibuttons per altitudinal interval for replication and averaging purposes. I have the average temperatures for each altitudinal interval (average of three ibuttons for each elevational interval) and have split the data according to seasons. I would like to interpolate the averaged seasonal temperatures of to create a temperature layer (interpolate to a DEM) which I would then want to use as a covariate for occupancy modelling of a vulnerable species of lizard. The other problem is that in the south of my study site the elevation is ca. 1450m (see attached map for context)  for which I have no temperature data so I would have to interpolate outside of my known data points (if that makes sense). How can I do this in ArcGIS (if it is possible to do)? ... View more