Large segment size in DSM limit the spatial resolution of density covariates

[Laura]

 In open landscape with species (e.g. large ungulates) detected at great distances, the recommended segment size will be large (2w x 2w). The landscape heterogenity within these segments can be large and important covariates of density distriution may only be detected at fine-scale resolution. Has there been any recent advances to enable smaller segment sizes (while accounting for increased probability of segments autocorrelation)? We work towards obtaining environmental variables with greater spatial resolution, but then still need to lump them coarsly... 

[Eric Rexstad]

Laura

We understand there is a tension between large segment sizes and spatial heterogeneity within the segment in predictor variables. Shrinking the segment size may reduce within-segment heterogeneity, but at the same time will likely increase the proportion of empty segments in your analysis. I don't know if there have been advances to resolve this tension.

One (non-ungluate) paper that has investigated the effect of segment size upon estimates is

• Redfern JV, Barlow J, Ballance LT, Gerrodette T, Becker EA (2008) Absence of scale dependence in dolphin–habitat models for the eastern tropical Pacific Ocean. Mar Ecol Prog Ser 363:1-14. https://doi.org/10.3354/meps07495

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Sent: 22 July 2025 09:21
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Subject: {Suspected Spam} [distance-sampling] Large segment size in DSM limit the spatial resolution of density covariates

 

 In open landscape with species (e.g. large ungulates) detected at great distances, the recommended segment size will be large (2w x 2w). The landscape heterogenity within these segments can be large and important covariates of density distriution may only be detected at fine-scale resolution. Has there been any recent advances to enable smaller segment sizes (while accounting for increased probability of segments autocorrelation)? We work towards obtaining environmental variables with greater spatial resolution, but then still need to lump them coarsly... 

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