5238results about How to "Accurate acquisition" patented technology

As an embodiment of the present invention, in a navigation system using an acceleration sensor, when position information cannot be obtained from a GPS processing section, a velocity detecting unit performs an operation using detected acceleration αG, a measurement time mt, a velocity V0 at a time t0, gravity acceleration g and an amount of height change Dh, according to Expression (11). By using the relationship among a gravity acceleration component gf, the gravity acceleration g, the amount of height change Dh and distance Dm shown in Expression (4), the gravity acceleration component gf can be offset by the amount of height change Dh. Therefore, velocity V can be calculated with high accuracy without receiving the effect of the gravity acceleration component gf.

A method for geometric calibration of a CT scanner, including, for each row of at least one row of detector cells, establishing a complete geometric description of the CT scanner, including at least one unknown geometric parameter, establishing a description of a forward projection function using the complete geometric description, acquiring actual projection coordinates of a calibration phantom placed in a scanning field of view (SFOV) on a current row of detector cells and corresponding to a plurality of angles, acquiring calculated projection coordinates of the calibration phantom on the current row of detector cells and corresponding to the plurality of angles using the description of the forward projection function, and acquiring a calibrated value for the at least one unknown geometric parameter by evaluating the at least one unknown geometric parameter based on the acquired actual projection coordinates and calculated projection coordinates via a nonlinear least square fitting algorithm.

Location method for locating a portable device (1) from a server (2) configured to communicate with said portable device (1) through a wireless communications network (3), in which said portable device (1) comprises a transmission / receiving module (12), an A-GPS positioning module (11) and a microprocessor (15) configured to manage said modules (11, 12), in which the method comprises the steps of: sending GPS assistance information from the server (2) to the portable device (1) through said wireless communications network (3); obtaining in an A-GPS positioning module (11) of the portable device (1) a GPS signal (4) from a satellite system (8); calculating in said portable device (1) a location of the device (1) itself from said GPS signal (4) and from the GPS assistance information sent by the server (2); sending said location to the server (2) from the transmission / receiving module (12) through said wireless communications network (3). It also comprises the steps of: when the portable device is stopped, hibernating the A-GPS positioning module and the microprocessor, maintaining the transmission / receiving module turned on; and when the portable device is in an area in which it is receiving service from said wireless communications network from a cell recognized by said device and stored in a memory thereof, turning off the A-GPS positioning module, such that the server can provide position information associated to said area without having to interrogate the device, thus saving the battery and increasing the autonomy of the portable device.