CAP SLOW SCAN TV (SSTV)
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Update: Slow Scan is still in use, but the SDIS (satellite digital imaging system) has proven to be more techically compatible with the average CAP user, has shown better quality, and is generally more reliable. SSTV is great technology, but it is likely on its way out. There has been considerable interest lately in the use of Slow Scan television (SSTV) for Civil Air Patrol operations. These forward-thinking people are welcome and we hope they continue to investigate this exciting technology. The uses of SSTV in Civil Air Patrol are wide. Many people have already explored using the technology for damage assessment and other disaster relief activities. The idea here was that an aircraft launch and photo a floodplain, fire, bomb, or earthquake damage field. The image(s) recorded are then sent to the emergency operations center (EOC) or equivalent with a slight delay for transmission time. Turnaround? Less than 2 minutes. This was the original concept of operations. Civil Air Patrol operators need to expand this concept. The relatively recent release of new commercial slow scan equipment has the capability to revolutionize the way we think about SSTV and can even distinctly modify the way we do business. This "new" piece of equipment has been on the market for about a year, and marketed mainly to amateur radio hobbyists. You can go to Kenwood's site to see this product, the Kenwood VC-H1. The VC-H1 boasts a wide variety of features, including its small size, battery operation, multitude of functions, built-in camera, and built-in image display. With this unit (and a transceiver radio) you can send as well as receive digital images. Contrary to what you may read below, you can also use a separate camera with the unit. This will allow you better zoom capability. Members have used video cameras and digital cameras to accomplish this task. The scenario of an aircrew locating a target and then directing a ground rescue team to said target is well proven and rehearsed. We've been able to modify that scenario in recent years with the popularization of LORAN and Global Positioning System receivers. Aircrews now only need to find the target, relay the coordinates by radio to the ground team, and then return to base. While it is advantageous for the ground team and the survivors' morale that the aircraft remain on station until the ground team arrives, it is no longer necessary. What if an aircrew could, in addition to the simple
latitude-longitude coordinates, relay to the ground team a
god's-eye-view of the objective?
In an ideal world, every aircraft would have the BEK Advanced Materials, Inc. Slow Scan TV setup. It is a very durable, user friendly, and capable. When hooked up to a GPS unit, it can even include the lat-long of the photo's vantage point. The BEK system is fully self-reliant and is compatible with all the CAP prototypes and is compatible with the Kenwood VC-H1. The chief problem of this system is its cost: advertised at "under $10,000." I can reasonably see a wing having one or more of these units, but most individual members and even squadrons will not be able to raise that sort of capital. For sake of argument, however, lets say that each aircraft in your wing is equipped with the BEK Advanced Materials setup. Should only the folks back at mission base or in the EOC be able to view the images? So long as the equipment is properly set up, ground teams (as well as other ground units and even other aircrews) with a VC-H1 unit should also be able to receive and view the images. Furthermore, a ground crew that is properly equipped could even relay an image through the aircraft to the mission base if they are not in direct contact. I would think that mission coordinators would love near-real-time imagery both from the aircraft and on the ground. And I'm sure that ground team leaders would love imagery of their objective before they get there--that way they can at least go to the largest piece in the most expeditions manner possible. Ground team leaders would probably also like to know the extent of the debris field for a variety of reasons (security, area search, etc). A picture truly does say a thousand words. Foreseeably SSTV could even be used by the mission staff in the tasking of ground and air assets. During a missing person search, aircraft are only marginally successful at locating human-sized targets. If an aircrew could simply gather imagery of potential search areas, an MC could then assign dog a team to one area and a regular ground team to another, as terrain and foliage dictated. SAR SSTV can also help preserve and record the accident scene for the post-accident investigation. Images of undisturbed wreckage are always useful. Since the NTSB often delegates the investigation to FAA Ops inspectors for general aviation accidents, this would probably anger the Aircraft Owners and Pilots Association (AOPA), but I'm convinced they'll whine at ANYTHING the FAA does, simply because its the FAA. Yes, I'm an EX-AOPA member. Since a VC-H1 can act as a speaker-microphone, it is very possible to replace your aircraft radio's handheld microphone with the VC-H1. This allows the observer access to all pieces of necessary equipment and temporarily eliminates another microphone. Furthermore, it eliminates the need for another (dedicated) radio, as many setups are currently designed! All the observer needs to do is take the picture, switch the CAP FM radio to the appropriate transmit frequency, and send the photo. He or she can even warn the folks before switching off the voice freq. The extendible cord may even allow limited operation by the scanner in the back seat. Mississippi Wing is working on a VC-H1 setup such as this to complement its current stand-alone VC-H1 and VHF-FM radio combinations. The necessary step is a patch cord: more information and pictures to follow! Currently Mississippi's SSTV transmissions have been on an airborne HT using a rubber duck antenna from inside the aircraft. Its not the ideal, but it has worked so far! The link above is to images taken at the November 13, 1999 Evaluated SAREX. Mississippi garnered and OUTSTANDING rating due in part to its progress in SSTV operations. One Civil Air Patrol wing in the Northern part of the country has acquired a forward looking infrared system (FLIR, about $10,000). They are currently fitting it to the cargo door of a Cessna 172. It puts out normal video and still photos. This type of an application is ideally suited to the VC-H1, which can accept virtually any video source. The unit will digitize and transmit (via a radio, of course) that video still. We own the night! Care to know my take on the VC-H1 versus the BEK system? The VC-H1 is the 90% solution at less than 5% of the price. I personally think that this piece of equipment was slighted in favor of garnering more public funding for the more expensive (and, admittedly, tougher) system. Another huge advantage of the VC-H1 is that you don't require a personal computer to view the transmitted images. While the VC-H1 is not secure nor is it rugged, these qualities are not truly a requirement for the CAP user: if you can take care of your GPS unit, you can take care of your VC-H1. Be nice to it, and don't play Army. My first introduction to SSTV was a poor one. Due to poor planning on the part of the mission communications director, the same frequency that was used for voice air to ground communication was also used for SSTV air to ground communication. Thus every several minutes the aircrew and ground team were completely out of contact. Not a life and death situation by itself, but it significantly added to the time on target as well as being very frustrating. Please ensure this doesn't happen to you. Want to know more about the nuts and bolts of slow scan television? A SSTV Handbook is available online. Want to see what other CAP units are doing with SSTV? California Wing's Jon E. Kramer Composite Squadron 10 of Palo Alto has a Slow Scan Video Demonstration online. Texas Wing Liaison website also has some SSTV Samples. My current Wing, Mississippi, has some aerial photos online taken with and sent by the VC-H1 unit. Outstanding! This will give you a fairly concrete example of the capability of the VC-H1. Judge for yourself. AvWeb recently ran this article about CAP SSTV. Well worth a look! It recently occurred to me that an essential piece of information is missing in most SSTV images. Even though some images can have the GPS coordinates titled right onto them, the direction the camera is facing can elude even the most astute of observers. The solution? For those people sending an image, keep a log. Within that log keep write the direction that the camera was facing at the time of the photo. For time-critical transmissions, such as those to a ground team, include a separate voice transmission relaying the same information. During listserver discussion, Captain Will Flor of Wisconsin Wing had the following to say: He [Malcolm Kyser] doesn't say that it can't be used with an external camera; he says that "Both the Kenwood and the CSI systems can offer a variety of optional camera choices", which is certainly true. I usually use a Kodak digital camera as the video source, and it works pretty well. The main VC-H1 drawbacks that I've encountered are that it eats batteries, so it really needs to be powered from the aircraft electrical system, and the "power saver", which automagically turns the display off to save batteries, always does so at the most inopportune time. Luckily, it's pretty easy to turn this off. Of course, if you want to use the panel-mount FM, you need a way to interface the VC-H1 to it; building an interface box took me about 20 minutes and $4.00 or so in parts from Radio Shack. This interface box allows me to switch the panel-mount FM between audio panel and SSTV modes. To me, not a policy maker but an ES person in the field, the main advantage that the VC-H1 has is...we have them. We flew a nuclear power plant disaster drill this past week, and flew for the Governors' Conference the week before, both involving SSTV (whatever state you live in, your governor has probably seen SSTV pix taken and transmitted by me, because most governors were at the conference.) We used the VC-H1 because we had them...where were the CSI-100s? I have yet to see one, therefore they are not adequate. You can't use what you don't have. It's that simple. In further discussion, Dave Jeffries of South Dakota Wing had this to say: There is a another MAJOR plus to the Kenwood selection: Since the Kenwood set uses one of several "standard" amateur SSTV formats there are many other systems capable if interfacing with it. For example : Perhaps your local Amateur ARES/RACES unit with their station already in place down at the county EOC would be able to receive the data also, allowing the EM director to see what is going on while we directly serve the On-Scene Incident Commander with our ground gear. This is only one possible scenario available with the use of compatible equipment. The CSI-100 sets that we received are, I believe, compatible with nothing other than another CSI-100. Kind of like having an FM radio that only allows you to talk ONLY with others of the same brand and model. Don Wood of Florida Wing related this about the current cost of SSTV systems. He states: The base price of the BEK units (March 1998) is $5195 for the airborne unit (camera not included) and the ground unit is $4525. Any needed radio equipment is extra. The Kenwood unit is currently being sold (price from Amateur Electronic Supply http://www.aesham.com/ken.shtml ) for $350. Additional cost would include any needed cables ($40 or 50 dollars). At this point I am looking at either $9600 for a complete transmit and receive set for the CSI-100 type unit or $1000 dollars for two of the Kenwood units (one for the aerial unit, one for the ground receive unit). The price differential is hard to ignore. Being able to utilize the Kenwood units either in the air or ground would increase their utility. Editor's note: The following is a copy of the text sent out by LtC Maurice "Moe" Thomas of National Headquarters. It compares both of the pieces of equipment mentioned above and is well worth a read. Anything in brackets [] has been added by the CAP ES Resources website. After careful evaluation of both the Kenwood [VC-H1] and the CSI-100 [BEK Advanced Materials SSTV package], I have come to the following conclusions: 1. The Kenwood VC-H1 system pluses: offers a small, lightweight integrated system suitable for field use were a lack of sophistication and ready mobility are the primary considerations. The unit is suitable for all ground picture assessments by teams where the system is utilized as designed. The speed of deployment and availability of units will be the primary considerations for the mission. The receiving end of the link can be commonly available multimedia PC components to store and display pictures for evaluation. Security and privacy cannot be issues when using this system. The unit is easy to use, economical, and can run entirely on small batteries. It has a 10-frame buffer and a built in titler. It has many features available with outboard devices and options. The Kenwood unit has a built-in LCD display that makes it easy to frame and capture a picture. It is capable of all amateur standard slow scan formats. When used as designed and within its operating limitations, it is and excellent field piece for CAP. The unit does not require integration with other components to operate effectively. 2. The Kenwood VC-H1 system minuses: is not built to withstand the rigors of severe use in hostile environments. The unit will not be reliable if it is dropped, gets wet, or where the application requires additional electronics plugged into the unit, such as outboard cameras, GPS data, outboard power supplies, outboard video displays or recorders, and audio input/outs to the unit. These additional cables and functions will quickly remove its size and weight advantage as well as tend to reduce the reliability of the system. The case is consumer grade plastic with molded case jacks that will wear out prematurely if used over a long period of time. The integrated CCD camera produces acceptable pictures for images if taken at 5-25 meters from the subject and the subject is well illuminated. The system has limited depth of field and the Zone 1 sphere of focus is 75% of the picture field making it totally unacceptable for serious airborne survey work. Kenwood's built-in LCD display is small, has a limited viewing angle, and cannot be viewed easily in direct sunlight. The lack of automatic relay ability limits the unit to light of sight single link distances. The transmission format has no intrinsic security and none can be added in the video path. The video output from a similar receive unit can be displayed and recorded on any available consumer grade equipment but does not produce broadcast standard signals. The operating status of the unit is not immediately known with available indicators. The fusing and or circuit protection devices are not easily accessible. It is a fixed format package with no known upgrade path to digital video transmission. 3. The CSI-100 system requires component assembly by an electronics technician that has somewhat above average skills in systems integration. It has durability and reliability by simple virtue of its design and construction. Each of the CSI-100 system integrators had a common design goal, but with different implementations dependent on the perceived needs of the customer as well as the user. Features were recommended based on actual field utilization and experience. The use of additional components such as displays, cameras, GPS data, video titlers and distribution, outboard power supplies, outboard video displays or recorders, and audio input/outs to audio recorders and phone patches are optional components of the CSI-based designed integration. The selection of these additional components is dependent on the wants and needs of the customer. Each additional function adds to the system's size and weight. 4. All of the CSI-100 based system packages are built to withstand the rigors of severe use in hostile environments. Each CSI-based fabricated unit will be reliable if it is dropped or gets wet. It was built with the intention that it could withstand hostile, military-like environments. Packaging adds directly to the reliability of the CSI-based system. The cases used by Code Red, BEK, and the CAP prototype are all commercial grade high impact plastic made to accept considerable wear and tear as well as accidental abuse. A design objective would be to be able to easily replace any system component in the field and have a minimum of downtime. 5. The operating status of the CSI unit is immediately known with available indicators. The fusing and or circuit protection devices are easily accessible for reset or replacement. 6. The CSI-100 native signal has intrinsic security in that it cannot be easily decoded by a casual observer or unintended recipient. The CSI has the ability to share pictures sent to multiple receive locations and still remain relatively secure. In technical terms, both units use amateur Robot 36 and Robot 72 formats. The CSI unit has a proprietary header format but is capable of standard transmissions, externally selectable. It is a flexible format package with projected upgrade paths to digital video transmission. 7. The CSI-100 automatic relay feature allows the unit to extend its range beyond single link path distances if and when properly coordinated. Both signals can have extended range via available voice repeater links. 8. There has been considerable feedback on this issue in connection with the selection of and need for a video recorder and displaced GPS data. The design requirement for an independent video recorder is being considered. 9. The Kenwood unit wins for size, weight, price, and field agility. It is an amateur radio solution that is ideally suited for mission applications that fall within its design parameters using the unit itself, its own camera, and an associated transceiver. The receiving station must be a suitable PC for its elemental success. If the PC is a desktop station, it requires knowledgeable setup. If the computer is a laptop model, it must have a reliable source of power. The operator must have the requisite computer skill to receive and process the pictures. A second Kenwood unit and a means of recording the picture product is another possibility. If Kenwood were to produce a ruggedized commercial version of this unit, many of its mechanical limitations that affect reliability would disappear. The Kenwood VC-H1 is the correct solution for those applications where its economy make it available for ground assessments on short notice and where it can stay within its design parameters. Any other use voids its economic and field agility advantage. 10. The CSI-100 unit wins for ruggedness, reliability, flexibility, and security. It is a professional solution that is ideally suited for those applications where reliability and simple front panel operation are paramount. There are format agility options that allow for unsecured transmissions and reception on common PC workstations. The CSI-100, when packaged in a lightweight case and a minimum of add-ons, is the professional solution for airborne survey. 11. Both units offer robust signal transmission on commonly available FM and telco circuits that offer channel quieting better than 10 dB. Neither unit's signal is suitable for HF transmission on marginal circuits. While HF transmission is possible, multipath and selective fading will seriously degrade the linearity and resolutions of the received picture, making them difficult read and interpret for evaluative purposes. 12. Video I/O performance issues: Certainly the camera chosen to work with any of the CSI systems could also have a built-in screen. The display used in the aircraft must be small and light weight with low power consumption. The screen must be large and bright enough to be viewable in direct sunlight. Both the Kenwood and the CSI systems can offer a variety of optional camera choices for a wide variety of applications (thermal, night vision, high contrast black-and-white, electrical domain). Both units produce adequate 320TVL+ resolution pictures. Since the choice of camera is independent of the basic CSI-100 module, the most appropriate video source can be inputted to the unit without intermittent and unreliable jack connections as found on the Kenwood VC-H1. The apparent resolution will increase with higher quality video inputs. The CSI unit, with its DSP processor in the receiver, produces generally sharper pictures and high color resolution with much less chromanance-to-luminance delay and distortion. The CSI processor is capable of implying higher detail near the upper limit of its resolution if present on the input device. The CSI-100 decoded video output can be displayed and recorded on any available consumer grade equipment as well as produce broadcast standard signals without a PC. In order to capture and transmit the picture in a computer, a video capture device is required. No such capture device is required of the Kenwood unit. 13. Provision for upgrades to digital formats within the available bandwidth must be considered for the future. The packaging of the CSI-based unit means that only the basic codec unit would need to be replaced. The Kenwood system would require a wholesale unit replacement and a different decoding strategy at the receiving end. It is anticipated that there will be a solution to the bandwidth limit problem in the future. Automatically built MPG or JPG recompressed files could be sent by some packet technique that could be used for evaluative purposes. Effective throughputs would be a critical issue in any case. 14. System designers will add or modify market-driven features and performance that may well change the conclusions found in this report. The only rational conclusion is that we will have a mix of Kenwood units and CSI-100 based units in the field. The CSI-100 can create a signal that can be received in the clear by ordinary PC multimedia workstations as well as Kenwood VC-H1 units if that is a key mission requirement. Future enhancements that may allow fast-scan TV on compandored narrowband audio circuits must be considered a possibility if the commercial marketplace sees this as a need. PS: This report has been sent to all Region DCs and NHQ-DOK and NTC. You may share it freely. I have made an honest effort to be as objective as possible in this analysis. When responding to the issues raised here, please focus on the mission requirements and objective engineering considerations presented. Thank you. Maurice Thomas III, Lt Col, CAP Hello Ted! I REALLY appreciate you comments and the time you spent
composing your message to me. The CAP ES Resources(tm) website is only
as good as those who contribute to it. It isn't an official CAP site; it
is a private site intended to help out CAP. Neither does it purport to
be official--its purely information. I have no qualms, however, about
revising or changing an opinion or recommendation when it is warranted.
That being said, I would also like to post your comments on the page!
The intent is for an open forum. If there's a place where I wish to
include my opinions, I do so. The point between the BEK system and the
VC-H1 is that with neither does anyone need to put anything together.
They're complete systems. The VC-H1 is NOT the perfect solution, and at
$10k, neither is BEK. The VC-H1 gives a simple operating capability with
minimum training--an absolute premium in CAP. I am personally interested
in entertaining your third option, and would love it if you would be
able to provide a parts list. You also mentioned a VC-H1 based
system--if you could provide a parts list for that as well, I could
easily envision a line-by-line cost and capability comparison--based on
what you're telling me, someone moderately technically inclined could
put together a significantly more capable CSI-100-based system at a
reasonable, if not cheaper (when you include the VC-H1 necessitates a
decent camera to be viable), cost. I personally think that the aircraft
radio is a good option, particularly if they're standardized throughout
the wing. Easy to do in backwards Mississippi when you only have 6
aircraft. In any case, I will put up a link to the url you mentioned.
I'll even raise you--would you be willing to put together some
information regarding the system you put together, and how someone from
CAP Wing X could replicate it? _THAT_ is the goal of the CAP ES
Resources website. From: RTedA@aol.com To: |
This page of the CAP Emergency Services Resources™ website was last updated 02/04/2007
©1998 - 2007 Scott E. Lanis. All Rights Reserved.
SSTV makes this possible. If a mission coordinator can view an image
of the target, he or she can begin to verify (or not) that the object
located is, indeed, the search objective. The point is that SSTV has
its place in search and rescue as well as disaster relief missions.
Information regarding its use in counterdrug missions remains
controlled. In this photo, we see a parachute target photographed from
1,000 feet AGL with a Kenwood VC-H1 unit. While the clarity is not
crystalline, it is certainly adequate to describe to a ground team the
relative location of the target. Imagine the accompanying radio call,
"100 meters Southeast of the pond."