Thread Tools
Jul 14, 2005, 04:53 PM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP

Low Altitude Large Scale Reconnaisance - LALSR


My goal has been to create a sufficiently detailed aerial photograph of an area of archeological inerest that I can use it for a presentation to the BLM. On the last flight I got 81 pics ( I posted some of it). They were from 9 passes 9 shots each spaced 1.3 seconds apart at 1/1000th second shutter speed. I made a composite of 20 frames for the picture below. In Photoshop it is 24" wide and 20" high. I split it into 9 8x10 rectangles, printed 9 glossies and glued them to a sheet of foam board. The result is spectacular.

The presentation is in Power Point and uses the composite interspersed with Terra Server stuff and aerial and ground shots. As back up I have the composite minimized in Photoshop. You can pop it up on the screen then zoom in and out with the magnifying glass and move around with the hand. Not too shabby.

The area covered is about 600 feet square. Model altitude varied from 80 to 150 feet. I tried to cover additional area but ran into serious radial distortion problems. I have an idea of how to do it - try that next time.

AP is great! I'll let you know how the presentation goes.
Sign up now
to remove ads between posts
Jul 14, 2005, 05:11 PM
HeliAP'er!
Hogster's Avatar
WOW!! You've done an amazing job with that! Particularly considering how the height of the model wasn't constant the whole time .... how does this photo compare to a map of the area?

Fantastic work Tom!
Jul 14, 2005, 05:34 PM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
I started basing this work on a topo map. But topo's are only accurate to 180 meters. That's about a third of one side. As I tried to plot points the topo became useless. That's why I decided to use AP.
Jul 29, 2005, 10:12 AM
I'm Ginger & called Adam
Ginger Adam's Avatar
It's a shame there's not some software similar to this - http://www.snapdv.com/ for making tiled images from video.

Adam
Jul 29, 2005, 12:42 PM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Adam,

Cool link. Pretty intensive software. I'd like to let software do the task.

Stitching videos would be wild but I'm afraid the resolution is too low to be useful.
Jul 29, 2005, 05:10 PM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Presentation Results:

Made the first level presentation and got some results. I have a list of contacts to follow for possible State Programs for citizens to identify and preserve historic sites. What I am trying to do is get some official interest in these El Camino trackways. Need some kind of recognition so if I get caught doing soil conductivity surveys I don't get thrown in jail.

Did get an invitation to submit a paper for a conference next April. It is the "Instituto Nacional de Antropología e Historia" (sounds neat - huh) here in Socorro. It is an international organization with a strong interest in the El Camino Real.

Also got the name of a state BLM archeologist who has done some aerial surveys with full size aircraft. He may be the best next contact.

Hope to get some more AP tomorrow. I want to work on an area with more interesting features than ground up sand. We shall see.
Jul 29, 2005, 06:55 PM
I'm Ginger & called Adam
Ginger Adam's Avatar
I would have thought it's possible to generate a pretty good map from a sequence of hundereds of low-resolution images if you have the right software ? As long as the subject remains relatively still (scenery) then it does not matter that the image has been generated from a huge number of VGA quality stills @ 25 frames per second ?

The original software was (I heard) developed from some software that mapped the seabed from video feed from submersibles. Seems a very similar application to generating a detailed visual map from AP source.

Adam

Quote:
Originally Posted by Tom Harper
Adam,

Cool link. Pretty intensive software. I'd like to let software do the task.

Stitching videos would be wild but I'm afraid the resolution is too low to be useful.
Jul 29, 2005, 07:05 PM
Ascended Master
Sparky Paul's Avatar
To replace my dying Casio Exilim, I picked up a Nikon Coolpix 7600.
7.2 megapixels..3072x2304
7.8 to 23.4 lens.... (38 to 114 in 35 mm)
There's two interesting shooting modes..
Continuous, 4 frames every 3 seconds, for 14 frames,
and
Multi-shot 16, 16 frames consecutively, 1600x1200 images.
For getting a series of images on a single flight path, it has potential.
5+ oz with battery (2xAA).
SD card
3.2"x2.4"x1.5"
The lens extends with power on, so I'll be adding some type of lens protection to the plane I fly it in.
Jul 29, 2005, 10:46 PM
Registered User
Hey Sparky,

Have you figured your effective FOV with that lens? I mean, I know what a 38mm lens will get you at 1000 feet, but I reckon you have figured out the EFFECTIVE area of coverage at several different altitudes.

CTF
Jul 30, 2005, 06:48 AM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Sparky,

That sounds like a nice camera. Bet it set you back a bit. 5oz is nice I'll check it out.

These ~1 sec frame rates are just a little too fast unless you are flying right on the deck. I'm going to try running the lens half way out on telephoto to see if I can get about 50% overlap.

Gotta call Carl in an hour to get him away from his house painting long enough to go do some AP.
Jul 30, 2005, 07:03 AM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Sparky,

Looks like $300 street price for the Coolpix plus $50 for a 1 gb SD. Awsome and tempting.
Jul 30, 2005, 10:54 AM
Did You Hear That?
wattnoise's Avatar
Really cool project, Tom... Could you give more details as to what the El Camino trackways are?...

Kevin
Jul 30, 2005, 12:30 PM
Ascended Master
Sparky Paul's Avatar
Quote:
Originally Posted by Tom Harper
Sparky,

Looks like $300 street price for the Coolpix plus $50 for a 1 gb SD. Awsome and tempting.
.
Depends on which side of the street you're on..
The prices locally vary $60 for the camera..$400 at Circuit City, $340 at Best Buy across the street. and the 1G cards are $100.
I got the 512M at $31.
The LCD monitor can be powered down, which is good since we have no need for it in AP, saving battery power.
The field of view wth a 38mm lens from 1000 feet is about 890'x670'.
The camera doesn't have the RAW mode.
It saves in jpeg.
The usual excellent Nikon 540x480 30 fps video. Can be plugged directly into a tv or VCR.
Last edited by Sparky Paul; Jul 30, 2005 at 01:58 PM.
Jul 30, 2005, 06:08 PM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Sparky,

I was using eBay. Thinking about it.

Wattnoise,

I'll post a thread on the El Camino track ways.
Jul 31, 2005, 06:39 AM
Lift is cheap - Drag sucks
Tom Harper's Avatar
Thread OP
Sparky,

I can't find any specs on the 7600 shutter speed.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Fantastic Video (full scale) low altitude airflap Aerial Photography 16 May 09, 2007 08:03 AM
Low Altitude Large Scale Reconnaissance Tom Harper Aerial Photography 94 Aug 13, 2004 04:13 PM
Large Scale Electric Sailplane Report Dave Wenzlick / Slickraft Electric Sailplanes 36 Jun 18, 2002 11:24 AM
Best Large Scale Electric Heli new2heli Electric Heli Talk 23 Mar 12, 2002 10:11 PM
RDS (rotary driver system) and large scale models. Aero-BearAZ Scale Kit/Scratch Built 1 May 27, 2001 11:00 PM