Changes between Version 12 and Version 13 of Sensors/LeicaLIDAR/FWMikesNotes

Timestamp:

Apr 10, 2013, 7:20:47 PM (11 years ago)

Author:

mggr

Comment:

Clarifications

Sensors/LeicaLIDAR/FWMikesNotes

@@ -20 +20 @@
 The full waveform digitiser (FWD) is supplied as an upgrade to the existing ALS50v2 (and up) sensors, and essentially consists of an upgraded data logger and an intensity digitiser (the FWD).  The discrete point recording subsystem is unchanged.  In implementation, the FWD is added as a spur after the automatic gain controller (AGC).  There is a trigger from the discrete system to the FWD that tells the FWD when to start recording.
 {{{
-                                                 +--->  Full waveform digitiser   -->--+
-                                                 |                 ^                   |
- Laser receiver -> Automatic Gain Controller  -->|                 |                   |-->  Data logger
-                                                 |                 |                   |
-                                                 +--->  Discrete point subsystem  -->--+
+                                                 +--->  (fixed gain booster) ---> Full waveform digitiser -->--+
+                                                 |                                     ^                       |
+ Laser receiver -> Automatic Gain Controller  -->|                                     |                       |-->  Data logger
+                                                 |                                     |                       |
+                                                 +----------------------->  Discrete point subsystem  -->------+
 }}}
 
@@ -52 +52 @@
  * the .LWV files cannot be easily linked to the .SCN (discrete files) - there is no direct linkage between LWV file 2 and SCN file 2
 
-
-
-
-where did gain come from in waveform viewer
+Where did gain come from in waveform viewer?
  - volts= digitized value * gain + offset
  - not agc gain, this is a fixed amplication on the waveform board
@@ -62 +59 @@
  - system digitises from 0 to 4.something volts
  - gives you volts as received at the waveform board, after AGC applied, etc - probably only useful for engineering team
-  
+   * More information on gains and corrections to remove the AGC effect is at [wiki:Sensors/LeicaLIDAR/FWMikesNotes/FWGainDiscussion]
 
 ops changes: various.. relevantish ones to us are