Application: uSimModemNetwork

Brief Synopsis:

Request/Response service module returning the current multipath eigenray solution for a transmitter/receiver pair in a underwater modem network.

Authors:

  • Henrik Schmidt

Groups:

Dependencies:

Distribution:

  • lamss.mit.edu

Contact Email:

  • henrik@mit.edu

Function:

Upon request returns the instantaneous multipath eigenray solution (delay, amplitude, doppler etc.) for a transmitter/receiver pair in a multinode modem network. Intended for real-time timeseries generation for dynamic modem networks in a variable Virtual Ocean, it implements a highly efficient nested environmental acoustic modeling framework. Thus, it maintains a database of the sound speed profile in all vertical ocean slices in the network, regularly updated via requests to uSVP_OceanModel, typically once a minute. Using the latest svp updates it continuously updates an eigenray database for each transmitter/receiver pair via requests for raytracing solutions to iBellhop, covering a grid around the receiver, typically each 5-10 seconds. When requested, the eigenray solution is then achieved through simple ray interpolation in the receiver grid and returned through the MOOSDB with a delay of order 0.1 second. Supports arbitrary volumetric receiver arrays. uSimModemNetwork is the principal computational acoustics module in the NETSIM hardware-in-the-loop modem network simulator. However, starting in ICEX20 it has also become a core topside utility for environmentally adaptive modem network control. Thus, another request/response service returns a suite of communication performance metrics for a transmitter/receiver pair, which can then be used for either manually or automatically selecting an optimal network transmitter for commanding a particular undersea asset.

Lines of Code:

  • 2,347 (with libraries: 11,233)

Files of Code:

  • 3 (with libraries: 53)

Work Years:

  • 0.49 (with libraries: 2.45)