Feature group

Feature

Sigma

Cableless systems with only shootblind capability

Cableless systems with some data return capability

Benefit of feature and related issues

24 or 32 bit

32 bit

Mostly 24 bit

Mostly 24 bit

Limits use, especially for passive operations.

Memory, address limitation

2 TB limit

In some cases limited to 2 or 4 GB

In some cases requires maintaining real time link or system will not function

2/4GB and/or need for real time link may be too restrictive.

Data output

SEGY & SEGD

Most offer only one data format

Most offer only one data format

International norms vary,needing both data formats.

Operating temp. range

-40 to +85 deg C

Most systems have more limited range

Most systems have more limited range

Lower temperature range restricts operations.