Hi,

who did not knows, there is the free program called SAS.Planet. With this everybody can download satelite image with kml calibration file. Then just using IMC like we always do with RM raster images we can have satelite pics layer on HDS screen. Very easy and usefull.

sasgis.ru/

p.s. webpage in russian language only, but program itself is in English .

Hello rimart,


thanks for the tip. This program is very interesting.
But i only find a export option for aerial photos with 96 dpi resolution. This would be to little for the most use in HDS (but good for RM background). Do You have found other export options with more dpi?


Best wishes
fjordfisher

Jorg,

with most of these applications - thats why they are free....... !! You want better you gotta pay!

T

Correct, only 96 dpi photos. But I tryed on my HDS 7 - looks ok for me. In compare with Navionics Platinium+ for my area and these that I did my self using SASPlanet plus vector map with GME and depths with RM, my map looks a lot better for me :)

Yes, it's much better/possible. I only mean, that the zooming is not so good or You need a lot of more part-pictures for the same effect. With other GIS applications (no problem with 300 ... > 1.000 dpi) is the effort much lower.
I would ever prefer GIS applications like ArcGIS, GM etc. if possible. But i don't know, which resolution i can accomplish in QGIS (not tested). Have anybody experience with max. dpi from aerial photos in QGIS?



Best wishes
fjordfisher

спасибо!! (spasibo!)

I have been trying for sometime (6-8 months) to create a map file which will display a satellite image on a Lowrance HDS unit. Comments in this thread have given me hope. I have been recording sonar logs and generating contour maps for several years (Dr Depth and now Reefmaster) but I am absolutely GIS illiterate. I have done a ton of reading (hours and hours) from this forum and the various program help files trying to figure out how to make such a map, but all of my efforts have hit roadblocks and ended in frustration. Everyone here makes it sound easy, but for this dumb engineer this stuff is tough.

Here is where I have been:
Of course I own Reefmaster, have IMC, downloaded SAS Planet, and bought WinRar. Will get whatever else is needed.

I outlined a very small test image from Google Earth (one screen at zoom level 20) in SAS Planet and exported a .kml file. This file opens in Reefmaster but even though I have read the help file many times I cannot figure out how to export this "background" in any way to generate the necessary raster files for IMC conversion. I just got stuck and I don't even know if this is a necessary step, so I moved on to import the .kml directly into IMC.

In the IMC instructions under Keyhole there are instructions for importing a .kml. I can bring the file in, and then chose "Build". It says process complete and data appears in the Status Window, but I cannot find any output. The instructions indicate to extract a .kmz or .kml with WinRar to create a folder of files to be used for raster map generation. I bought and ran WinRar, but it will not create a folder containing the maps like the example shows. This seems pretty simple, but who knows what I am doing wrong. I tried renaming the .kml to .kml.zip as shown but this didn't work either. I just continue to get errors.

This forum is filled with great mapping experts and I almost feel embarrassed to post here, but I am so frustrated with this project that I broke down to ask for help. In the Midwestern US we fish a lot of flood control reservoirs and the aerial photographs often show very valuable structure information under low water conditions. The ability to see these images on a locator is 10 times more valuable than contours will ever be for certain sections of these reservoirs.

Currently I view the aerials using my Toughbook while on the water, but that requires an internet connection and chews up data time. Having a map on the locator would be much better. I am sure there are better ways to get the aerial maps on the Toughbook as well but I have not figured that out either.

Thanks in advance for any help. Danny and Jorg I appreciate your help in the past, but I just keep getting stuck because of my lack of GIS knowledge.

Hi Talon,

Welcome to the Reefmaster Forum.

From now on, you will produce your own Lowrance compatible aerial maps within a few hours.
We can assure you.

Hi Talon,

First up, RM does not export images to AT5 (yet!). We may well add this in the future - possibly quite soon.

For now, you need to do this using the IMC, and if you are starting with a KML/Z file, then it is a two stage process (in the IMC).

Firstly, create your KML/Z file as you have done. If you create a KML file for your image, then the KML file only contains information about the image - you need to make sure that the original image file is in the same directory as the KML file when you run the IMC. If you have a KMZ file, then the image file and the KML calibration file will both be contained within it (KMZ files are just zip files that hold other files - it makes things a bit more convenient).

Now - the IMC:

The IMC raster process does not use KML files. Instead it used a different type of calibration file known as a "world file", with the extension .pgw. "Keyhole" mode in the IMC simply reads the KML calibration file, and produces an equivalent .pgw file that you can then use in raster mode.

(note: I have just run through this process, but I have used a KML file and an associated .png image file throughout - I cannot state for sure that this works exactly the same with KMZ files, because I don't have one to hand for testing).

1. Open up the IMC and go to Keyhole mode. Add your KML file, and make sure the image file is in the same directory. Click Build. You should now have a new file in the same directory as the KML file, with a .pgw extension.

2. Go to Raster mode in the IMC. You need to add your image file here. Note that the IMC accepts folders only here, and adds all image files within the folder. You can make your life simpler by making a new folder which contains just your .pgw and image file. Set an appropriate min and max resolution. These values refer to pixels per metre of your original image. The IMC will rescale your image to match the values you use. I wouldn't sweat this one too much - just run with 1 - 8 for now. You can play with these values once you get used to the process (to determine the native resolution of your image, divide the width in pixels by the width in metres. You can find the width in pixels by right-clicking the image in Windows explorer and looking at the properties). Set your work directory, and click Build.

You should now have some output files in a directory called "BoundAT5s" sitting underneath your build directory. Copy these to your map card in a directory called "ShadedRelief" located at the root of the card (to be honest, I am not sure if the shaded relief directory is actually necessary).

Give that a go and report back if you have any problems.

Matt

Thanks Danny, I appreciate your confidence and hope to share it one day. Right now I feel like a can being kicked down the road in all directions as I try to absorb mapping information.

Locating and catching fish is easy compared to most of this, but the potential benefits of learning are obvious.

When our lakes rise (8-20 ft) and water covers the stumps shown in the aerial photos, they often hold some good fish, especially crappie. Being able to target the best looking stumps from the aerial photographs would be a huge advantage.

Unbelievable Matt. You are very fast.
I just completed the process myself, just to check.

Now I wanted to explain how to do it. And there it was already.

Nice,

Talon,

Just put these AT5-files in a folder ShadedRelief on your SD-card.
Put your HDS on Lowrance Charts Mode and Imagery= ShadedRelief.
Here you can find the (small) Raster AT5 map on 51° 39°N and 4° 10'E. (zoom in far enough)
Just as an example. It was built just the way Matt has described.


Edit,
Talon, I have sent them by email. I couldn't post it here.