I've read a bunch. There is some good test data out there:
http://offshore.ussailing.org/Assets/Of ... st.pdf.pdf
My question is, does anyone know what the radar image of a PDQ 32 looks like? I strikes me there is a lot metal there already, and many have mentioned that they feel a reflector is redundant. I am sure on a large boat it is rather ridiculous. We do have masts, wiring, barbecue grills, davits, smoke stacks, solar panels - the list varies with the boat, of course - and thus there must be some signature.
I don't sail in high-fog areas. If I did I would run radar and they would certainly see that emission first.
How stealthy are we? Has anyone seen another PDQ or similar boat using radar? Sandy?
Radar Reflectors
Radar Reflectors
Writing full time since 2014.
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- admiral
- Posts: 694
- Joined: Fri Oct 05, 2007 10:57 am
- Location: Orlando, FL S/V DogHouse PDQ32009
Re: Radar Reflectors
My Raymarine radar easily shows boats much smaller than a PDQ. I pick up individual marker signs on the ICW. The only thing it doesnt show are those damn crabpots!
In heavy seas markers and such could be lost in the sea clutter but I think a PDQ would still have a nice cross section.
In heavy seas markers and such could be lost in the sea clutter but I think a PDQ would still have a nice cross section.
- eepstein
- admiral
- Posts: 194
- Joined: Mon Jul 21, 2008 5:29 pm
- Location: Annapolis, MD (PDQ36 Hull 49)
Re: Radar Reflectors
A friend of mine just wrote a book on radar reflectors which also covers in detail, the image a boat shows on a radar. Here is the link. http://www.amazon.com/gp/product/193058 ... s_prod_img
In my much more limited and simple view as a communications engineer, I can summarize and say that depending on the sea state and range setting of the vessel's radar, a PDQ or any good sized cruising sailboat could look anything from very clear or practically invisible.
For instance, A ship with a radar mounted very high above the water, utilizing a long range setting to see the entrance to an inlet in the distance, say 20 miles away, will not see anything within a mile or two. Objects farther may return a small yet clear, or small and intermittent reflection depending on the sea state.
Such variables are one of the reasons that AIS has become so popular, so fast.
Hope this helps.
In my much more limited and simple view as a communications engineer, I can summarize and say that depending on the sea state and range setting of the vessel's radar, a PDQ or any good sized cruising sailboat could look anything from very clear or practically invisible.
For instance, A ship with a radar mounted very high above the water, utilizing a long range setting to see the entrance to an inlet in the distance, say 20 miles away, will not see anything within a mile or two. Objects farther may return a small yet clear, or small and intermittent reflection depending on the sea state.
Such variables are one of the reasons that AIS has become so popular, so fast.
Hope this helps.
Eric & Bonnie Epstein
s/v Desert Star, PDQ36, Hull 49
Annapolis, MD
s/v Desert Star, PDQ36, Hull 49
Annapolis, MD
Re: Radar Reflectors
Google radar + ouzo for a very depressing summary of the effectiveness of radar reflectors on small sailboats in average conditions. This is REAL stuff, not theory or lab testing. I'm retired from the NTSB. I consider Britain's MAIB to be the best in the world, so I give great credence to their findings because they are absolutely independent of commercial pressures and belligerently objective.
No radar reflector is worth its price, or even the scratches on your mast's anodizing if someone gave you one free.
I believe in AIS. For $200 you can see a ship coming 15 miles away. For $600 they can see where you are. AIS is about to be mandated on 17,000 more commercial vessels in U.S. Waters. I am NOT saying that AIS is a substitute for radar. Not, not, not. Both is best, but get AIS if you can't get radar.
The biggest problem with radar reflectors is that so many sailors think they work much, much better. The tragedy is when they let that belief lead them into danger.
No radar reflector is worth its price, or even the scratches on your mast's anodizing if someone gave you one free.
I believe in AIS. For $200 you can see a ship coming 15 miles away. For $600 they can see where you are. AIS is about to be mandated on 17,000 more commercial vessels in U.S. Waters. I am NOT saying that AIS is a substitute for radar. Not, not, not. Both is best, but get AIS if you can't get radar.
The biggest problem with radar reflectors is that so many sailors think they work much, much better. The tragedy is when they let that belief lead them into danger.
Sandy Daugherty "Page 83" PDQ 36026
Thanks for the replies
My reading of the data agreed with all that has been said hear.
In my work I have tuned numerous lab instruments for noise and gain; the constant is that you tune for what you are looking for and to ignore the rest.
I have always held that believing ones self to be invisible is the best bet.
In my work I have tuned numerous lab instruments for noise and gain; the constant is that you tune for what you are looking for and to ignore the rest.
I have always held that believing ones self to be invisible is the best bet.
Writing full time since 2014.
"Rigging Modern Anchors,"Seaworthy Press, https://www.amazon.com/Rigging-Modern-A ... 1948494078
Book Store. http://sail-delmarva.blogspot.com/2017/ ... store.html
"Rigging Modern Anchors,"Seaworthy Press, https://www.amazon.com/Rigging-Modern-A ... 1948494078
Book Store. http://sail-delmarva.blogspot.com/2017/ ... store.html