need help in 2d reflection land survey

[fairyland]

hi,
i'm planning to run 2d reflection survey at an area with interest depth of 200m.
need help on the parameters of the survey design.
how to determine the offset, record length and sampling rate or any other parameters need to consider during planning a survey line?

is there any book or journal to share?

thx..

[jeepster]

That is pretty shallow. Just off the top of my head, I would say you need 1 ms sample rate. Your far offset would be a bit more than your target depth. So something like 96 channels at 2.5 meter spacing. For a split spread that's 192 channels.
I think 5 m receiver spacing would be too coarse for shallow work.

[fairyland]

hi jeepster
my purpose is to detect cavity and may using 24 to 48 ch.
is it
a) max offset 200m
b) min offset 50m
c) geophone spacing 2.5m
d) record length ?
e) sample rate 0.1ms
6) fold 12fold
7) source interval 5m
8) seismic line inline with cavity

appreciate if can answer my questions.
thanks

[kochichiro]

I think you should better use electro-magnetic survey (from airplane, for example) -

[link Point to another website Only the registered members can access]
It provides you with far much better results on shallow depths.

[jeepster]

I have no experience in cavity detection. I think you will need a high-frequency source, such as Betsy shotgun, or preferably drill shotholes and try 25 gram boosters. Single geophones with a frequency of 30 Hz would be preferred. Also time the shots when the wind is quiet so
you could do a bit of spectral boost in processing.
I doubt there is a book on the subject. You might find some papers about cavity detection in the EAGE or SEG conference abstracts.