NavCom StarUtil-3000 Rev.G - Manual (Page 172)

StarUtil 3000 User Guide – Rev G
11-170
 Output start time / Output end time: If enabled, the Output Start and Output End times allow
the user to parse a large raw data file into a smaller snap shot of the overall data collection
period. Caveats are that the GPS Week Number, and the GPS Time Of Week (TOW in
seconds) be entered. Refer to the sections below,
GPS Week Number and for details on
these values.
 If the Output Start and Output End times are disabled, the RINEX Utility will process the
entire data collection period.
GPS Week Number
The GPS Week Number count began at midnight on the evening of 05 January 1980 / morning
of 06 January 1980. Since that time, the count has been incremented by 1 each week, and
broadcast as part of the GPS message. The GPS Week Number field in the data stream is
modulo 1024. This meant that at the completion of week 1023, the GPS Week Number rolled
over to 0 on midnight GPS Time of the evening of 21 August 1999 / morning of 22 August 1999.
The SF-3040 and SF-3050 use an adjusted 16-bit integer (U16) in the data to avoid this
confusion. They can handle up to week 65535.
For example, in Figure 161 the GPS Week Number for the Output Start / End times is 1313. To
determine the week/date, subtract 1024 from 1313, which is 290. Then add 290 weeks to 21
August 1999. The result is Sunday 6 March 2005.
GPS Time
The GPS time (seconds into the week) always starts on Sunday morning at 00:00 GMT. Each
24 hour period contains 86,400 seconds. A full week contains 604,800 seconds. Please see the
table below for a breakdown of hourly / daily increments.
Table 17 : GPS Time
GMT Sun Mon Tue Wed Thu Fri Sat
0:00:00 0 86400 172800 259200 345600 432000 518400
1:00:00 3600 90000 176400 262800 349200 435600 522000
2:00:00 7200 93600 180000 266400 352800 439200 525600
3:00:00 10800 97200 183600 270000 356400 442800 529200
4:00:00 14400 100800 187200 273600 360000 446400 532800
5:00:00 18000 104400 190800 277200 363600 450000 536400
6:00:00 21600 108000 194400 280800 367200 453600 540000
7:00:00 25200 111600 198000 284400 370800 457200 543600
8:00:00 28800 115200 201600 288000 374400 460800 547200
9:00:00 32400 118800 205200 291600 378000 464400 550800
10:00:00 36000 122400 208800 295200 381600 468000 554400
11:00:00 39600 126000 212400 298800 385200 471600 558000
12:00:00 43200 129600 216000 302400 388800 475200 561600
13:00:00 46800 133200 219600 306000 392400 478800 565200
14:00:00 50400 136800 223200 309600 396000 482400 568800
15:00:00 54000 140400 226800 313200 399600 486000 572400
16:00:00 57600 144000 230400 316800 403200 489600 576000
17:00:00 61200 147600 234000 320400 406800 493200 579600
18:00:00 64800 151200 237600 324000 410400 496800 583200
19:00:00 68400 154800 241200 327600 414000 500400 586800
20:00:00 72000 158400 244800 331200 417600 504000 590400
21:00:00 75600 162000 248400 334800 421200 507600 594000
22:00:00 79200 165600 252000 338400 424800 511200 597600
23:00:00 82800 169200 255600 342000 428400 514800 601200
23:59:59 86399 172799 259199 345599 431999 518399 604799

Example: 518400 = Sat 0:00:00 GMT