gga.java

国外的一个开源gps模拟器源代码

/*
 * Copyright (c) 2007 by the University of Applied Sciences Northwestern Switzerland (FHNW)
 * 
 * This program can be redistributed or modified under the terms of the
 * GNU General Public License as published by the Free Software Foundation.
 * This program is distributed without any warranty or implied warranty
 * of merchantability or fitness for a particular purpose.
 *
 * See the GNU General Public License for more details.
 */

package ch.fhnw.imvs.gpssimulator.nmea;

import ch.fhnw.imvs.gpssimulator.data.GPSData;

public class GGA extends NMEASentence {

	@Override
	public String getName() { return "GPGGA"; }
	
	@Override
	public String getSentence(boolean content) {
		String sentence;
		if (content) {
			String ns = GPSData.getNS().name().substring(0,1);
			String ew = GPSData.getEW().name().substring(0,1);
			
			StringBuffer buf = new StringBuffer(getName());
			append(buf, getTimestamp()); 			// time position is taken in UTC [hhmmss.ss]
			append(buf, NMEASentence.getNMEALatitude());		// latitude [ddmm.mmmm]
			append(buf, ns);						// [N|S]
			append(buf, NMEASentence.getNMEALongitude());	// longitude [dddmm.mmmm]
			append(buf, ew);						// [E|W]
			append(buf, GPSData.getQuality());	 	// GPS Quality: 
														// 0 fix not available or invalid
														// 1 GPS mode, fix valid
														// 2 DGPS, fix valid
														// 3 PPS, 4 RTK, 5 Float RTK, 6 Estimated, 7 Manual, 8 Simulator
			append(buf, GPSData.getSatellites());	// Number of satellites being tracked [<=12]
			append(buf, GPSData.getHDOP());			// Horizontal dilution of position [d.d]
			append(buf, GPSData.getAltitude());		// Altitude, above mean sea level
			append(buf, "M");						// Altitude unit
			append(buf, "0");						// Height of geoid (mean sea level) above WGS84 ellipsoid
			append(buf, "M");						// Height of geoid unit
			append(buf, "");						// time in seconds since last DGPS update
			append(buf, "");						// DGPS station ID number [0000-1023]
			sentence = buf.toString();
		} 
		else {
			sentence = "GPGGA," + getTimestamp() + ",,,,,,,,,,,,,";
		}
		return sentence;
	}

}