Is there a managed library for reading the coordinates from a geotiff file in .NET ?
I know it can be done thru GDAL, but I am looking for a managed alternative.
You can use the GDAL included .NET wrappers. This allows you to access any of the GDAL functionality from within managed code.
You won't see many in managed C#, due to the performance and memory usage limitation imposed by the .NET Framework memory management layer. Don't get me wrong -- I love C# and .NET. However, native C++ is much faster and (in my opinion) less frustrating to write, in this case.
Surveys typically contain many GeoTIFF files, which requires a lot of memory and manipulation of data, when performing geotransforms (i.e. WGS82 to UTMM to TIFF X-Y coordinate, and then back again.) Demand for memory performance and management efficiency increases further, when you involve things like compiling results of linear, radial, and area surveys.
You probably don;t want to hear this, but writing a parser in native C++ and then wrapping it into C# is going to greatly increase performance and eliminate memory limitations. Writing a parser is actually pretty easy, and will be very lightweight, as you can tailor it to your needs. You will find this particularly true, when integrating more advanced features, such as automatic selection and spanning of GeoTIFF files.