Marine Electronics Forum - Radar application questions

Hello,
I would like to do a small application using a radar and would like to ask some questions before proceeding and buying all the staff. I know that radars are good detecting boat miles away from them but how good they operate when boats are close (less than 100 meters) and how good is it distinguishing boats that are close to each other.

Application Description:
A radar will be installed in a harbor and be connected to a computer. I want to write a program that will be able to count how many boats are in the harbor and also send alert when a boat is entering or existing the harbor.

Is this feasible or radars accuracy does not allow to distinguish between boats close to each other? Can radars see close or only far? Is it easy to interface with a computer? What messages they send (is there a standard format)?

Thanks

Regarding the interface, your NOT going to get that kind of info here, try calling the respective companies and talk to R&D. You may still not get what your looking for, good luck.

As far as accuracy, they are fairly accurate these days, but boats all packed together get p[retty dicey. The new broadband radar might do what you are looking for, but still, it will not be an exact science.

Here is what radar and LOTS of boats looks like at close range. This was during a fireworks show a few summers ago using Garmins 24HD dome:

http://www.thehulltruth.com/attachments/marine-electronics-forum/181281d1309886087-garmin-radar-images-24hd-dome-radar_1.jpg

http://www.thehulltruth.com/attachments/marine-electronics-forum/181279d1309886087-garmin-radar-images-24hd-dome-radar2.jpg

http://www.thehulltruth.com/attachments/marine-electronics-forum/181282d1309886087-garmin-radar-images-24hd-dome-range3qtr.jpg

Hello,
I would like to do a small application using a radar and would like to ask some questions before proceeding and buying all the staff. I know that radars are good detecting boat miles away from them but how good they operate when boats are close (less than 100 meters) and how good is it distinguishing boats that are close to each other.

Application Description:
A radar will be installed in a harbor and be connected to a computer. I want to write a program that will be able to count how many boats are in the harbor and also send alert when a boat is entering or existing the harbor.

Is this feasible or radars accuracy does not allow to distinguish between boats close to each other? Can radars see close or only far? Is it easy to interface with a computer? What messages they send (is there a standard format)?

Thanks

No problem seeing close (ie >30 meters). As far as distinguishing between boats, should be no problem as long as they are at least 2-3 degrees apart and or the farther boat more than 110% of the distance to the nearer boat. If a smaller boat is behind, but in line with a larger boat, you will not see it. You will also have to deal with false echos, at the risk of rejecting real returns.

A camera image may be as good, or better, than a radar image for your purposes.

May not be legal (without a license) to use on land.

the tough part will be the computer interface. I suspect you will end up digitizing the radar's video output. Otherwise, all very doable.

Thanks guys for all the information! Nice shot Birdman! This explains what I wanted to see. So the dense boats in the center how close are they and how far from you?

Do you think I will need a heading sensor for this application (the radar will be installed on land and it will not be rotated like boats are doing)?

I can see also that chartplotters process the information from radar and generate NMEA sentences described in this link:

http://www.marimsys.com/pages/nmea_codes.htm

So I can connect to NMEA bus and parse these messages and see the coordinates of all targets?

In my 2nd image posted, the range rings (lite white cirlces around the image) are 1/16th of a nauticale mile each. So the first ring is 1/16th of a mile from my boat, or 380 feet.

1 Nautical mile = 6076 feet

6076/16 = 380

So you can see the first couple of boats (closest ones) are about 1/4 of the distance between me and the 1st range ring, or about 380/4= 95' which in boating, is pretty close.

The Navico (Lowrance/Simrad) BroadBand Radar will be in a class by itself for your application.

http://www.panbo.com/archives/2011/12/simrad_broadband_radar_4g_hands-on_1.html

Contact Navico, they previously sold a software development kit for this radar, according to what I've heard a new scheme for developing third party applications for the BroadBand Radar will be released later this year.

I don't know abbor, if you compare my images (normal radar) with the panbo broadband images, mine look better!! I keep hearing the broadband radar is earth-shattering, but then I never see any images that impress me?

Panbo's articles are complete waste of time. He bables about how great a product or technology is, then posts images of it that don't look any different than anything else.

Thanks Birdman! So I can undestand that even the 18HD will be enough for my application (I do not need the 24HD since we are talking about extremely small distances).

Thanks Birdman! So I can undestand that even the 18HD will be enough for my application (I do not need the 24HD since we are talking about extremely small distances).

24 will give better target seperation which is very important for your application, no?

After reading these two reviews you will probably not consider Birdman as the definite authority when it comes to radar performance anymore:grin:

http://www.pronav.no/gendocs/PracticalBoatOwner_June2011_Radar.pdf

www.pronav.no/gendocs/4G_PBO_Article_Nov2011.pdf

BroadBand Radar is most probably the only radar where you will be able to get documentation for the interface.