Point Observation - ashtech Z-Xtreme System Manual

For post-process surveying

Hide thumbs Also See for Z-Xtreme:

Operations & reference manual (62 pages)

System manual (102 pages)

Quick start manual (6 pages)

Table Of Contents

Table of Contents

You have a landfill that you need to topo. Being that the project site is a

landfill, most of the area has no obstructions with the possible exception of

trees along the perimeter. You set up your base station in an open area.

You then set up your rover system. You turn on the rover system immedi-

ately. As you finish your preparation, the rover system is collecting data

for initialization on some arbitrary location. After two minutes, you are

ready to begin locating topo points. You decide to start at the northeast

corner of the landfill because it is wide open with no obstructions. It takes

you approximately 1 minute to walk to the location of the first topo shot.

By this time, you have already collected 3 minutes of data that will be used

towards your initialization. You begin collecting topo points. In the next 2

minutes, you have collected 4 topo points without lose-of-lock. By this

time, the system has collected 5 minutes of data, enough to initialize.

Without hesitation, you continue with your survey.

When this data is processed, the kinematic survey will initialize using the

data collected during the start of the survey. Even points collected prior to

initialization will result in precise positions.

You successfully continue to collect topo points for approximately 30 min-

utes without loss-of-lock. You now are in the perimeter areas were there

are trees close to the edge of the landfill. While attempting to locate topo

points right on the edge of the trees, the kinematic alarm in the receiver

sounds indicating that you have loss your initialization. You must now re-

initialize. It is good practice to establish a re-initialization point near an

area where you think you may loose lock. This is done by simply driving a

PK into the ground and observing this point prior to entering into the

obstructed area. If lose-of-lock occurs, you can simply observe the re-ini-

tialization point for 10 seconds to regain initialization. As an alternative,

once you loose lock, you can move out of the obstructed area and collect

data on other points where there are no obstructions for approximately 5

minutes, giving the system enough clean data to re-initialize. Then move

back into the obstructed area to collect more points.

On-the-fly initialization is an effective method for initializing your kinematic survey

since there is no time wasted waiting for the system to initialize. But, you must be

careful that you collect clean data during the initialization period or you run the risk of

getting poor positions on some of your points.