Galaxy G6
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5)Power on, confirm the static mode, the mainframe begins to search satellites and satellite lights
begin to flash. Recording condition reached, the status light flashes in accordance with the set
sampling interval, flashing once indicates the acquisition of an epoch.
6)After the test, the mainframe shut down, and then begins data transmission and data processing
(data transmission sees Chapter IV, data processing, please read another manual GPS data
processing software operation manual).
§7.1.4 GPS Net Design
The net design mainl subject to the users requirement, but outla , time interval of
observation,
type of receiver and the receiver amount, etc also relate to the net design.
In order to satisf the users requirement, we should keep the principle as follows:
1. GPS net normally forms closed graph by independent observation borders, such as triangle,
polygon or connecting traverse, etc, to add checking conditions and to improve the net
consistency.
2. When designing the net, the net point should be superposition with the original ground net
points. The superposition points are generally no less than three and distribute evenly on the net
in order to ensure the changing parameters between GPS net and local net.
3. GPS net point should be superposition with the level points, and the other points are normally
united
surveyed with level surveying way or the equivalent way. You can also set some level
united
surve ing points in order to offer geoid s information.
4. In order to observe and level united survey, we often set GPS net points at a clear and easy
arriving field.
5. We often distribute some well eyeshot azimuth points around GPS net to ensure united survey
direction. The distance from azimuth to observation station should be more than 300 meters.
According to different purpose of GPS surveying, independent observation borders of GPS net
should compose definite geometry graph. The basic graphs are as follows:
Triangle net
The triangle in GPS net is composed of independent observation borders, it has strong geometry
structure and well self-checking ability, it can also find out the coarse difference of result and to
share the difference to each baseline with adjustment.
But this net need a lot of observation, especially when receivers are lacking it will greatly
prolong the observation time. So only when accuracy and security are required very high, and
receivers are more than three, we can use this graph, see fig 5-3.
Circle net
Circle net is composed of many loops which are formed of many independent observation
borders. This net is similar with one of the classical surveying-- lead net. Its structure is a little
worse than triangle net. The amount of baselines in closed loop decides the self--checking ability