Attributed North American Grid-Based Offshore Sampling Frames

This sampling frame is a set of grid-based, finite-area frames spanning the offshore areas surrounding Canada, the United States, and Mexico, and is intended for use with the North American Bat Monitoring Program (NABat). A Generalized Random-Tessellation Stratified (GRTS) Survey Design draw was added to the sample units from the raw sampling grids (https://doi.org/10.5066/P9XBOCVV). The GRTS survey design algorithm assigns a spatially balanced and randomized ordering (GRTS order) to each cell within its respective framework. Grid cells are prioritized numerically; the lower the number, the higher the sampling priority. Cells can then be selected for monitoring following the GRTS order, ensuring both randomization and spatial balance. Monitoring within this standardized framework allows statistical inference to non-surveyed locations and ensures the validity of analyses at regional and range-wide scales. NABat is a continental collaboration including state and provincial, federal, and local agencies intended to standardize the collection and storage of bat data. Alaskan and Canadian waters are combined into a single grid. There are 5 grids in total: Alaska/Canada (AKCAN) Offshore grid, Continental United States (CONUS) Offshore grid, Mexico Offshore grid, Hawaii Offshore Grid, and Caribbean Offshore grid. Grid boundaries are based on World Exclusive Economic Zone oceanic political boundaries and extend into the shoreline 30 kilometers.

本抽样框为一套基于网格的有限区域框架，覆盖加拿大、美国及墨西哥周边近海水域，专为北美蝙蝠监测计划（North American Bat Monitoring Program, NABat）设计使用。研究人员从原始抽样网格中为抽样单元引入了广义随机镶嵌分层（Generalized Random-Tessellation Stratified, GRTS）抽样设计抽选方案，相关原始抽样网格的详细信息可参见https://doi.org/10.5066/P9XBOCVV。GRTS抽样设计算法会为对应框架内的每个网格单元分配兼具空间均衡性与随机性的排序（GRTS order，即GRTS排序）。网格单元按数值进行优先级划分，数值越小，抽样优先级越高。后续可按照GRTS排序选取监测单元，既保障了抽样的随机性，又兼顾了空间均衡性。在该标准化框架内开展监测工作，可对未调查区域开展统计推断，并确保区域及全分布区尺度下分析结果的有效性。NABat是一项大陆范围内的合作项目，汇聚了各州/省、联邦及地方相关机构，旨在统一蝙蝠数据的收集与存储规范。阿拉斯加与加拿大海域合并为一个单一网格。本次数据集共包含5个网格：阿拉斯加/加拿大（Alaska/Canada, AKCAN）近海水域网格、美国本土（Continental United States, CONUS）近海水域网格、墨西哥近海水域网格、夏威夷近海水域网格以及加勒比海近海水域网格。网格边界以世界专属经济区（Exclusive Economic Zone）的海洋政治边界为基准，向岸线延伸30公里。