Great Lakes CoastWatch Land Masks and Shoreline Data Files
URL Contents
http://coastwatch.glerl.noaa.gov/ftp/masks/gfx/ Modified [political boundaries REMOVED] versions of graphics data files supplied with IDIDAS v.1.5, which are higher resolution than the shoreline data supplied in CoastWatch image files. http://coastwatch.glerl.noaa.gov/ftp/masks/stream/ Above graphics data files in byte stream format. http://coastwatch.glerl.noaa.gov/ftp/masks/512/IDIDAS/lo_res/ Lower resolution masks embedded in CoastWatch image files. http://coastwatch.glerl.noaa.gov/ftp/masks/depth/ Great Lakes bathymetric data masks. http://coastwatch.glerl.noaa.gov/ftp/masks/1024/cwglsyrd_1024.byt Great Lakes high resolution (1024x1024) mask file (raw data). http://coastwatch.glerl.noaa.gov/ftp/masks/1024/cwglsyrd_1024.asc Great Lakes high resolution (1024x1024) mask file (asc format).
Data files have names of form "CWGLRRTT.EXT", where: EXT is the extension: GFX = Graphics data file in IDIDAS ANALYZE .GFX format, using compression type B. BYT = Graphics data file in byte stream format RR is the CoastWatch Great Lakes Region subscene covered by the file: EO = Lakes Erie/Ontario scene MH = Lakes Michigan/Huron scene SU = Lake Superior scene SY = Great Lakes scene TT is the type of data contained in the file: CL = coastline data LM = land mask data RD = land mask with lake regions defined by pixel value, as follows: (1) image size 512x512 Pixel Value Geographic Area ----- --------------- 00 Lake Superior 01 Thunder Bay 02 Black Bay 03 Nipigon Bay 10 Lake Michigan 11 Green Bay 12 Grand Traverse Bay 20 Lake Huron 21 Georgian Bay 22 North Channel 23 Saginaw Bay 30 Lake St. Clair 40 Lake Erie 50 Lake Ontario 100 Lake Nipigon 101 Lake Winnebago 102 Lake Simcoe 103 Lake Wanapitei 104 Lake Nipissing 255 Land (2) image size 1024x1024 Pixel Value Description of Defined Region ----- ----------------------------- 00 Lake Superior 01 Thunder Bay 02 Black Bay 03 Nipigon Bay 04 Western Lake Superior 05 Eastern Lake Superior 06 Whitefish Bay 07 St Marys River North 10 Lake Michigan 11 Green Bay 12 Grand Traverse Bay 13 Northern Lake Michigan 14 Southern Lake Michigan 20 Lake Huron 21 Georgian Bay 22 North Channel 23 Saginaw Bay 24 Northern Lake Huron 25 Southern Lake Huron 26 St Marys River South 30 Lake St. Clair 31 Detroit River North 40 Lake Erie 41 Western Lake Erie 42 Central Lake Erie 43 Eastern Lake Erie 44 Detroit River South 50 Lake Ontario 51 Western Lake Ontario 52 Eastern Lake Ontario 255 Land