Hi Reefmaster Team,

my name is Arnaud, I live in France and I have to use Reefmaster in my job to create lake maps. I used to use Dr Depth but I would prefer now develop some working methods with Reefmaster for me and other similar structures (fishing federations).

For the work I do, I need to exprort reefmaster map in a Geographic Informations System program (QGIS) to analyse, calculate and draw differents maps. With Drdepht, it is possible to export the map on .grd format («ESRI GRID-WGS 84 grid ") wich is really interresting for us because the picture is Georeferenced on the WGS 84 system and each pixel of the picture is associated to a depth (great for the map treatment).

Do you think it would be possible to have this kind of exportation option on Reefmaster?

many thanks for your answer!

Regards,
Arnaud

PS : Sorry for my english wich is not perfect!!! Hope you'll understand my request!

Hi Arnaud,
Thanks for the suggestion!
We already have ESRI grid export coming in the next release, which is due some time around the beginning of next month. There are also some other changes coming in that release that will probably be of interest to you - particularly the generation and (Shapefile) export of depth areas (isobaths).

Matt

Hi Matt,

Thank for your quick answer! The next relase seems to be perfect for me!

We keep in touch,
Cheers,
Arnaud

Surfer Grid Format (v6 or v7) wouldn't be a bad format to be able to export to, as well.

Thanks Greg - that looks like a simple format, so we may add that too, although it does not appear to be a geo-referenced format, nor does it support a "no data" value. I haven't used Surfer, so I don't know how much of an issue that would be.

Matt

It's georeferenced by SW corner and resolution specification.

The "no data" value is technically anything outside Z Low and Z High but we use -FLT_MAX internally.

Thanks Greg. I was looking at an older format (v6) - and missed the location fields.

gpiverson wrote:
Gregory, can you tell us what are the benefits of Surfer Grid Format? Or more in general, why should we use Surfer for? I am not familiair with that package.

DannyGeysen wrote:
ESRI's open grid format is ASCII text whereas Surfer is a straight binary format.

This makes Surfer faster to read by applications (and especially faster to read a specific depth within the grid because it can seek directly to it). Since the format is binary, the outputted files are smaller. The processed Z value ranges are available in the header which makes it so you can generate color scales while parsing only the header.

This said, I don't use the Surfer package but a ton of companies use their grid format (including Lowrance). The only thing I dislike about the Surfer7 is the data is stored with double precision (not necessary in a depth grid) and can't be toggled in a setting so we exclusively use Surfer6...when you have hundreds of gigabytes (and soon to be terabytes) of depth grids on hand, doubling the size of these depth grids can get expensive.