RTS File Format (RiverTools Sequence)RiverTools Sequence (RTS) files are a simple extension of the RTG file format that allow a sequence of RTG files to be stored in a single file. That is, an RTS file is a simple concatenation of RTG files that each have the same data type. The main purpose of this format is to provide support for landscape evolution models and spatially-distributed hydrologic models in the RiverTools environment. For example, a landscape evolution model produces a sequence of DEMs, each of which represents the topography of the landscape at a particular time in its evolution. Similarly, a spatially-distributed hydrologic model may produce a sequence of grids, each of which shows how water depths or discharges are distributed spatially at a particular time during a storm. The various RTG files contained within an RTS file are referred to as frames, and all of the frames are assumed to have the same data type. In version 3.0, only the 4-byte floating point or FLOAT data type is supported. In TopoFlow, the frames in an RTS file can be shown as an animation using Plot → RTS File. Alternately, the Display → Grid Sequence dialog in RiverTools 3.0 can be used to create animations, save them in AVI file format, or interact with them in various ways. Note that an RTG file with a data type of FLOAT is identical to an RTS file with a single frame. Unlike the file formats used for movies, no data compression is used in RTS files because that would result in a loss of information and each pixel of each frame is assumed to represent valuable data. As a result, however, RTS files can be quite large and must therefore be managed appropriately. Typically, the number of rows and columns for any given frame in an RTS file will be numbers less than 500. The filesize of an RTS file can be computed as filesize = (ncols x nrows x BPE x nframes) where BPE is the number of bytes per element or pixel. BPE is equal to 4 for the FLOAT data type and 8 for the DOUBLE data type. |