ASHTECH TIMESTAMP UNIT ProFlex Lite DG14

INTRODUCTION

On OBS surveys we need to time stamp shot events (when the airguns fire) to within the nearest millisecond, in order to synchronize this event to clocks in the seismic recorders that are operating autonomously on the seafloor.

This is the second-generation Ashtech unit we employ for this purpose.

SCOPE OF SUPPLY

The order in 2012 comprised the following positions:

--------------------------------------------------------------------------
  Pos  Qty   P/N     Description                     
--------------------------------------------------------------------------

   1   (1)  990656    ProFlex Lite DG14                        
                      Options:
                      - Event Marker (Photogrammetry)
                      -  1 PPS 1,2,5 & 10
                      Plus others as specified in email
                      dated 23 May 2012.

   2   (1)  802133    ASH-660 (L1 GNSS Antenna - 38dB)        

   3   (1)  702455-S  30m Low Loss LMR-240 GNSS cable     
                      (TNC male / TNC male)

Label on Proflex Lite box, with serial number

DOCUMENTATION

User's Manual

Download (also link to local copy)

COM port pinout

Ashtech DG14 COM port pinout, from page 13 in manual.

Unit configuration

Check options installed by issuing the $PASHQ,RIO command, ref.page 15 in the manual. Here is the response:

  $PASHR,RIO,DG16,DD04,,TOPUB_LE_C__YXDR___I,71168612DG6201222026*17

Attach:Ashtecg-GPS-timestamp-commands.txt

Old Ashtech GG24 config


; Setup for Ashtech GG24
: ===========================
;
; Reset with default settings
$PASHS,RST
;
; Set receiver in mixed GPS/GLONASS mode
$PASHS,SYS,MIX
;
; Set elevation mask to 10 degrees
$PASHS,PEM,10
;
; Send NMEA message GGA on port C
$PASHS,NME,GGA,C,ON
;
; Send NMEA message SAT on port C
$PASHS,NME,SAT,C.ON
;
; Send NMEA message ZDA on port C
$PASHS,NME,ZDA,C,ON
;
; Set NMEA "send message interval" to 1 Hz
$PASHS,NME,PER,1.0
;
; Set event marker signal to falling edge
$PASHS,PHE,F
;
; Set 1PPS trigger edge to falling edge
$PASHS,PPS,01.00,+000.0000,F
;
; Output Event marker message on port C
$PASHS,NME,TTT,C,ON
;
; Output Signal-to-Noise-Ratio (SNR) in dB*Hz
$PASHS,SNR,DBH
;
; Output Event marker time in GPS-system-time
$PASHS,TSC,GPS
;
; Save settings in battery backed-up memory
$PASHS,SAV,Y