{"id":495452,"date":"2022-02-22T19:11:42","date_gmt":"2022-02-23T03:11:42","guid":{"rendered":"https:\/\/www.esri.com\/about\/newsroom\/?post_type=arcuser&p=495452"},"modified":"2022-02-22T19:11:42","modified_gmt":"2022-02-23T03:11:42","slug":"noaa-buoy","status":"publish","type":"arcuser","link":"https:\/\/www.esri.com\/about\/newsroom\/arcuser\/noaa-buoy","title":{"rendered":"Site Suitability Modeling for Locating Tidal Buoys"},"author":1031,"featured_media":0,"menu_order":0,"template":"","format":"standard","meta":{"_acf_changed":false,"sync_status":"","episode_type":"","audio_file":"","podmotor_file_id":"","podmotor_episode_id":"","castos_file_data":"","cover_image":"","cover_image_id":"","duration":"","filesize":"","filesize_raw":"","date_recorded":"","explicit":"","block":"","itunes_episode_number":"","itunes_title":"","itunes_season_number":"","itunes_episode_type":"","_links_to":"","_links_to_target":""},"categories":[24962,1031,15412],"tags":[472461,477742,271],"arcuser_issues":[477652],"class_list":["post-495452","arcuser","type-arcuser","status-publish","format-standard","hentry","category-focus","category-natural-resources","category-oceans","tag-arcuser","tag-datum","tag-mapping","arcuser_issues-winter-2022"],"acf":{"short_description":"The author developed a suitability model that allows users to determine suitable anchorage locations for NOAA GNSS tide buoys.","pdf":{"host_remotely":false,"file":495462,"file_url":""},"flexible_content":[{"acf_fc_layout":"blockquote","content":"Editor\u2019s note: The author developed a suitability model that allows users to determine suitable anchorage locations for National Oceanic and Atmospheric Administration (NOAA) Global Navigation Satellite System (GNSS) tide buoys located in the US Exclusive Economic Zone (EEZ)."},{"acf_fc_layout":"content","content":"Identifying the anchorage of NOAA GNSS tide buoys is an important component that supports one of NOAA\u2019s primary missions: charting depths for safe and efficient navigation via its nautical chart suite. Deploying GNSS tide buoys to update vertical datums is the principle reason that this anchorage suitability model is important. [According to NOAA, \u201cA geodetic datum is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps. Horizontal datums measure positions (latitude and longitude) on the surface of the earth, while vertical datums are used to measure land elevations and water depths.\u201d]<\/em>\r\n\r\n "},{"acf_fc_layout":"image","image":495502,"image_position":"left","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"GNSS tide buoys allow NOAA to collect ellipsoid heights and water level data, evaluate the measurements, and empirically determine the vertical difference between the ellipsoid and tidal datums. [A tidal datum is a standard elevation defined by a certain phase of the tide.] Equipped with accurate information derived from tide buoys, NOAA hydrographers and cartographers can properly chart soundings (or depths), which use vertical transformations between the ellipsoid and tidal datum to convert in situ sonar depth data to the appropriate tidal datum such as Mean Lower Low Water (MLLW), which is the tidal datum used for the majority of US nautical charts. [MLLW is the average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch (NTDE). NTDE is a 19-year period established by the National Ocean Service for collecting observations on water levels and calculating tidal datum values.]<\/em>\r\n\r\nAs the quantity and density of measurements increases, vertical transformation models, also known as separation (SEP) models, increase in accuracy. Therefore, more buoys are needed to acquire more accurate data.\r\n\r\n "},{"acf_fc_layout":"image","image":495512,"image_position":"left","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"After extensive testing and validation of the anchorage suitability model, the use of GNSS tide buoys will be expanded to support NOAA field operations. This will require predetermining suitable locations to anchor the buoys. Buoys must maintain position for long durations under defined environmental conditions. It is equally critical that suitable anchorage locations for the buoys are established throughout the entirety of waters within the US EEZ. This is the area where the US government assumes jurisdiction over the exploration and exploitation of resources 200 nautical miles offshore from the nearest shoreline maritime boundary point.\r\nThe main objective of this project is to allow users to determine suitable anchorage locations for NOAA GNSS tide buoys in the US EEZ based on depth, slope, seabed, current, and wave characteristics using Python scripts that utilize GeoPandas [an add-on for the open-source Pandas library]<\/em> to manipulate tables and ArcPy, a Python site package, to create custom ArcTools that run suitability analysis and geoprocessing. The following steps were taken to facilitate the determination and evaluation of suitable anchorage locations for NOAA GNSS buoys:\r\n