View Selection - What are the elements of interest?

Different users may look at the same picture and see different things. A radio dispatcher may concentrate on activity in the foreground. Weather observers may look at the sky, and potential visitors may check out the scenery in the background. These "elements of interest" may be different for each user, yet it's possible for a single view to include them all.

The person or organization sponsoring your efforts should have particular elements of interest in mind to serve their intended audience. Their interests must be satisfied, or at least listed, prioritized, and met as best possible. (They may want more than they can afford.) At the same time, with little or no additional expense, you may find that the interests of other users might be served as well. Try imagining who they may be, and what they would find interesting. You may find a new type of customer in these users.

We can usually build a list of possibilities which easily exceeds our budget. Now it's time to prioritize and separate the "must" from the "want" items. You may want to start simple and expand later, after you have some experience with success. Don't lose the "want" list, there should always be a place for your dreams.

Some views will be selected because you need them. Significant investment may be required in order to get that view. Other views may be "targets of opportunity", where the infrastructure is largely present and it would be easy to add another camera. As you work to meet your "Must" priorities, consider what else may be possible for little additional expense.

Long distance visibility is a frequent casualty of the weather. If possible, include elements in a scene both near and far. In that way, when it gets really foggy, you'll have something to see besides the inside of a cloud. Even a nearby tree can be an assurance that when visibility improves, the view will return.

Respect the privacy of anyone who may be in the field of view for any reason. Exterior views are generally uncontroversial. Cameras inside buildings can be unwelcome, as most people don't like being "watched".

Site Selection - Where to place a camera

For each alternative, try getting a picture of the view from that location. This will help in site selection, and possibly serve as the first picture in your prototype web page. Other pictures may help with the design process, by noting where potential useful (or interfering) structures may be located. As you look around, realize that a site must meet a few fundamental criteria:

1. View
   • Does the view include the "must" elements of interest?
   • Are there other interesting views?
2. Safety
   • Does it avoid creating additional safety hazards?
   • Staying "out of the way" is a good idea not only for the safety of others, but also for the survivability of your installation. People may blunder into it by mistake, or heavy machinery may trample or bash it.
3. Agreement
   • Does the owner of the site understand what you are proposing to do, and do they agree to allow you to do it?
   • This may take a few discussions, as you may not appreciate the extent of the final site design until later in the design process.
4. Electrical power
   • Can you plug-in, or bring it from nearby, or will you need to generate your own power from sun, wind, propane or other energy sources?
5. Network connection
   • Can you connect to your network using wire or wireless methods?
6. Room
   • Can you fit all you need into the site?

Making use of existing structures for support and protection (like sign posts, towers, and buildings) can relieve you of having to build the equivalent yourself. This can save a lot of time, money, and effort, and minimize the visual clutter your efforts will bring to the scene.

When you share a resource like a building, consider your impact on the other users. Antagonizing them may get you invited to leave, or simply treated with contempt. Keeping hardware running often takes good will and cooperation, so try to locate your equipment out of the way and minimize resources (like electrical outlets) that you will be using. This can help protect you from accidental damage, as the other parties are not necessarily concerned with protecting your best interests.

This initial site survey might be all you need to start developing a site design. Dimensions and locations of support posts, towers, windows, wall space, and lengths of cable runs would all be handy. Determining the angular width of the desired field of view may be needed to select a suitable lens. A stick held at arms length can be used to estimate the angle (to be measured & computed later), or draw a map of the site and include sight-lines for the field of view..

Site Design

Notice that the problems aren't limited to "forseen" conditions. What you can imagine may be only a small part of what nature eventually throws at it. People, either disinterested or malicious, can add yet more challenges.

"Non-ideal conditions" may affect your installation in one of these ways:

1. It has no effect
   - This is the objective of good design.
   - Designing a problem "out of existence" may be required to achieve this.

2. It may degrade operation
   - Still working beats the next alternatives . . .

3. It prevents operation, but does no damage
   - Surviving to operate another day can be a reasonable strategy.
   - The ability to recover without manual intervention would be good, as needing to re-visit the site can become annoying.

4. It quits working due to damage
   - The design failed.
   - This can be a slow and expensive way to get an education, and it's bad for reliability and reputation.

• View is compromised
  • Reflections off a window from items (behind the camera) which are brighter than the scene you are trying to observe.
  • Window has fog, frost, dust or bugs on it
  • Sun on a window that's not perfectly clean
  • Obscured by vegetation or snow drifts at the window or somewhere along the view's path
  • Weather (fog, rain, snow)
  • Sun in (or near) the field of view
    - Staring at the sun can destroy some cameras
    - Simply looking at a bright sky (in the direction of the sun at noon) can bleach a camera's color sensor, and "burn" an image (like a mountain silhouette) into it.
    - During the course of a year the azimuth of the sun's rising and setting may vary widely. So will its altitude above the horizon. A simple azimuth versus altitude chart for your latitude might be handy.
  • Is not being able to see at night a problem?
• Environmental problems
  • Temperature extremes may exceed equipment ratings
    - Equipment can be exposed to this even if it isn't being used.
    - Summer heat - Sun-baked hardware under a skylight can become too hot to touch
    - Winter cold - For installations outside of heated buildings
  • Water (Due to humidity, flooding, wind-driven rain, snow, rime ice)
    - Including whatever may fall onto your installation from higher up on a tower or building
    - And if the door blows open during a storm?
  • Dust, insects, (gnawing) critters - getting into the equipment
  • Lightning strikes
  • Wind
  • Forest fires
    - Burning-down buildings is an obvious hazard
    - Disrupting utilities and preventing site access for weeks
  • Intentional damage - Due to vandalism and theft
• Power supply problems
  • Outages - short term & long-term
    - How long do you want to operate on back-up power?
    - What needs to be done before the next power outage?
  • Brown-outs - as power sources gradually fail
  • Power surges - from lightning, construction tools like circular saws, and chairlift variable-frequency drives
• Network problems
  • An outage that disables a node in a series of links.
• Sharing resources with other users in a building
  • Power outlets - enough remain available?
    - Else they may unplug some of your equipment
  • Views out of a window - camera is in the way?
  • Space to place equipment - in the way?

Not every problem requires a complex solution. Simple can be good enough, cheap, and reliable, but it may not be the first thing we think of when trying to solve a problem. (NASA invented a nitrogen-pressurized ball point pen for its astronauts to use in space. Cosmonauts used pencils.)

Almost every one of the above examples has happened, and could (but will not) be described in annoying detail. In the case of power line surge protection, we once lost a computer power supply due to someone using a circular saw plugged into the same outlet. Surge protectors need to be located between what is creating the problem and what you are trying to protect. Don't make your protected power outlets accessible for use by other users.

Frequently used solutions for some of the above commonly encountered problems:

Site Installation

Planning should start with the making of four checklists:

1. Tasks - What needs to be done, and in what order?
   - e.g. Install window, build shelf, mount stuff, connect it, turn-on, test operation, ...
2. Equipment - What are the major items to be installed?
   - e.g. Camera, video encoder, network interfaces
3. Supplies - What else is needed to make the "equipment" operational?
   - e.g. Tripod head (camera mount), outlet strip, low voltage control & power wiring, black-out curtain, shelf brackets, . . .
4. Tools - What is needed to put it together and check it out?
   - e.g. Drill, screwdrivers, multimeter, video monitor, laptop computer, scissors, . . .
   - This stuff will not be left at the site after installation is done.

• Access
• Lighting
• Demolition
• Clean-up
• Rude surprises
• Finalize plans
• Installation
• Testing
• Clean-up
• Inspections

A complete equipment list is important because forgetting a major item will mean that some part of the site design isn't going to work.

Supplies are the small stuff like wire, nails, wood, and conduit fittings that help mount things and connect them together. Forgotten supplies may not prevent an installation, but they can slow you down and affect the quality of the workmanship.

Tools, like supplies, can be critical or just nice to have. There is usually a "right" tool for every job, and likely many "wrong" tools that could do in a pinch. Using the wrong tool may adversely affect time, effort, and quality of workmanship. Be especially vigilant for tools which are infrequently used, as they are most easily overlooked.

These checklists are essentially another design effort, so a good "design" needs to anticipate more than just installation under ideal conditions. What additional issues might you encounter and need to handle?

• If you don't exclusively own the site, you probably will need to negotiate permission for access, and have an understanding of how much of the site you expect to occupy.
• How will you get yourself, equipment, supplies and tools to the site?
• If the site already exists, you may need to clear other user's stuff from what is to become "your" space.
• If the site needs improvements, you may get to install them.
  - e.g. If carpentry work is needed, both demolition and construction tools (and supplies) may be needed.
• If the job involves accessing high places, a ladder might be handy
• If the weather turns cold or wet, proper clothing and/or shelter
• If the job lasts after sunset, or includes dark spaces, a flashlight (or better)
• To assure your own ability to keep going, sufficient food and water
• A broom and trash container will probably be useful
• Most windows could benefit from a cleaning before the job is done.
• How do you test the installation and know that it's working properly before you leave the site?

Before taking equipment into the field, consider assembling and testing it in a location conducive to troubleshooting. New equipment may not work, or cooperate with other equipment. The place to find and fix these problems is where debugging is most easily done. Reading user manuals is much more pleasant in the shop, and you may discover issues that are best handled before going into the field.

Getting successful operational and troubleshooting experience is also handy. The experience you gain at the test bench may also help fill-out your tool and supply checklists. Ideally the field installation will involve little more than mounting the hardware, making connections, and verifying that it works. Take the User Manuals, they may be handy in case of difficulties.

The actual installation can be a bit like an expedition. Use your checklists, but stay flexible. The list (or order) of jobs may need to change, and unexpected conditions may prevent completing the installation in one visit. Success may need to come in stages, especially at remote and less-developed sites. Your first objective may be to establish a secure enclosure to store supplies and support later visits. Getting materials to a site can be more difficult than getting yourself to the site, so watch the weather and try to get structures closed-in, secure, and supplies on-site before access becomes more difficult.

Workmanship issues become important when reliability is concerned. Take the time to do things methodically and right. Check things out as you go, so that you can to rely upon whatever has been put in place. Don't assume you'll get back to correct some detail later; do it right the first time. Expect things to take longer than you want and you will rarely be surprised. Take a flashlight, because the day may end before you are done with the job. The penalty for oversights can be a flakey or inoperative installation, and needing to re-visit the site to correct what should have been done right the first time.

While doing the installation, note any unexpected situations. Wind whipping cables on a tower may lead to broken wires: Do you need to lash them down more securely, or route them in conduit? It has been said that most battle plans do not survive first contact with the enemy, and the same may be true for new designs. You may need to alter the plans during the installation. This also suggests that taking more than a minimal kit of tools and supplies may be useful to handle simple design changes.

If follow-up visits are required the checklists will be handy to make sure you take the right supplies and tools for the job. Keep adding to the lists as emergent issues and needs are identified, either in the field or as you prepare for the next visit. It's annoying to forget a critical part, and it may be a long time until the next visit.

If you expect to maintain the hardware in the future, doing (or at least being present during) the installation will help assure that you know where things are located. This can make subsequent visits less traumatic when you have to go it alone. Consider taking pictures of the installation, to help remind you of otherwise undocumented details. Pictures can also help clarify details when enlisting the help of others.

Site Operation

Network Management

We had five camera sites which are linked together on a network using wireless "bridges". The hardware is very flexible, which is another way of saying that it takes a bunch of setting configurations to get it running the way you want. We encountered the following considerations:

We chose to use "static" IP addresses, which are determined by the network's system administrator. (That could be you.) Addresses are assigned once and do not change. (DHCP is "off")

Every "bridge" box, network camera, video encoder and computer on the video network has its own unique IP address (e.g. "192.168.1.241"). Addresses are specific to this network and it's best if you keep a written record of the assignments. You'll need to know what IP address to assign when the next piece of equipment (like a visiting laptop) wants to join the network.

We created two types of local HTML web pages to work with the hardware on the network. The first page created was for network administrative use. It is used to test for connectivity to every IP address. Every live and static video channel on every video encoder and network camera can be tested from this page with a single click. The page's HTML looks like:

Filename:  index_admin.htm

<HTML>
<BODY>
<H2> Wireless Network Development Test Page </H2>
<P>
<HR>
<H3> Wireless Bridge boxes </H3>
<UL>
<LI> <A HREF="http://192.168.1.230"> 192.168.1.230 - At South Lodge, to Easy Rider  </A> (login / password)
<LI> <A HREF="http://192.168.1.231"> 192.168.1.231 - At Easy Rider,  to South Lodge </A> (login / password)
...
</UL>

<HR>
<H3> Nodes on the wireless network </H3>

<P>
<UL>
<LI> <A HREF="http://192.168.1.239"> 192.168.1.239 - Base area temperature sensor </A> &
     <A HREF="http://192.168.1.239/setup.html"> set-up page  </A> (login / password)
<P>
<LI> 192.168.1.241 - Lodge -
     <A HREF="http://192.168.1.241"> 4 channel video encoder </A> (login / password)
<LI> 192.168.1.241 - Lodge - camera #1 -
     <A HREF="http://192.168.1.241/index.html?cam1=on&size=1&columns=2&mode=0"> live </A>
   - <A HREF="http://192.168.1.241/jpeg.cgi?0"> static </A>
...
<LI> 192.168.1.241 - Lodge - camera #4 -
     <A HREF="http://192.168.1.241/index.html?cam4=on&size=1&columns=2&mode=0"> live </A>
   - <A HREF="http://192.168.1.241/jpeg.cgi?3"> static </A>
...
</UL>

</BODY>
</HTML>

The second HTML page was created for local users to access the camera views. It relieves the users of needing to know anything about IP addresses or the URL syntax: All they need do is click upon the view which is of interest to them. A "main" page displays six static pictures, and updates itself every 6 seconds. Hyperlinks connect to other pages, of which there is a separate page for each group of cameras, plus a page for each individual camera. This collection of web pages can be copied and used by any computer connected to any port on the network.

Filename:  index.htm

<HTML>
<HEAD>
<TITLE> Hoodoo Butte pictures (6 second update) </TITLE>
<META HTTP-EQUIV="Refresh" CONTENT="6">
</HEAD>

<BODY>
<TABLE BORDER=5>
 <TR>
  <TD>
   <CENTER> 
    <A HREF="index_Grn0.htm"> <! Full-rate URL here>
     <IMG SRC="http://192.168.1.245/jpeg.cgi?0" WIDTH="320" HEIGHT="240">
     Green Chair top </A> &
    <A HREF="index_Grn.htm"> related cameras</A>
   </CENTER>
  </TD>

  <TD>
   <CENTER>
    <A HREF="index_Ed0.htm">
     <IMG SRC="http://192.168.1.243/jpeg.cgi?0" WIDTH="320" HEIGHT="240">
     Ed Chair top </A> &
    <A HREF="index_Ed.htm"> related cameras</A>
   </CENTER>
  </TD>

  <TD>
   <CENTER>
    <A HREF="index_Base.htm">
     <IMG SRC="http://192.168.1.241/jpeg.cgi?1" WIDTH="320" HEIGHT="240">
     Base area </A> 
   </CENTER>
  </TD>
 </TR>

 <TR>
  <TD>
    ...
  </TD>

  <TD>
   ...
  </TD>

  <TD>
   ...
 </TR>
</TABLE>

<P>
<UL>
<LI> <FONT COLOR="FF0080"> Click the "<A HREF="index.htm">REFRESH</A>" button, or any picture,
     or any link to continue if this page stops updating.
     </FONT>
  <UL>
  <LI> The "failure to update" problem does not seem to happen if two computers are running this web page.
  </UL>
</UL>

</BODY>
</HTML>

The following HTML page displays displays a single camera's live picture, and returns to the main page after 60 seconds:

Filename:  index_Ed0.htm

<HTML>
<HEAD>
<TITLE> Ed Chair top (live) </TITLE>
<META HTTP-EQUIV="Refresh" CONTENT="60;url=index.htm">
</HEAD>

<BODY>
<iframe src="http://192.168.1.243/popup.html?0"
        width="725"
        height="500">
</iframe>

<CENTER>
 RETURN TO
  <A HREF="index.htm"> Main page</A> or
  <A HREF="index_Ed.htm"> Ed Chair camera group</A> now,
   or automatically return after 60 seconds
</CENTER>

</BODY>
</HTML>

The "index_Ed.htm" page referenced in the above web page shows a live view from the primary camera at the site, plus static pictures from the other cameras in its group. Clicking upon a static picture allows the user to see live video from that camera. Limiting these web pages to show one live picture at a time is intended to minimize the network traffic.

Before a new box goes on the network it needs to be configured, where at a minimum its network address is set. The network's system administrator determines what the IP address will be. A CAT5 "cross-over" cable may be needed to directly connect between the configuring computer and the new hardware in case the device's default IP address is incompatible with the network.

Hardware can be operated anywhere on the network where it can be plugged into an available port on a "switch". New cameras can be tested and configured in the office, before being deployed in the field. A laptop computer can visit each site, yet can check-out equipment located anywhere on the network. This transparency removes the need to go to a specific location to see how something is working.

Configuring the Hardware

Most of the hardware requires some amount of configuring to get it ready for operation. While there's no substitute for reading the instructions, here's an idea of what's involved.

Wireless Bridge

Determine the unit's default IP address, like "192.168.1.1", from the package or turn-on documentation. Connect the bridge to its power source, and to the network (or computer), and from an MSDOS window try to "ping" it (e.g. "ping 192.168.1.1"). You should get a 1 or 2 msec response time and 0% lost packets.

Access the box's network interface using an internet browser, using a URL that contains the IP address and looks like "http://192.168.1.1". You should look at and probably change many settings:

• Login name & password
  - Change any factory-provided passwords to keep out prying hackers.
  - Record what you changed them to, so you can find them in the future
• IP Address (to replace the default IP address)
  - e.g. "192.168.1.231"
• Channel number
  - e.g. "9"
  - (How do you check whether a channel is already in use?)
• Transmit power level
  - e.g. "+20 dBm" = 100 mW
  - Use the lowest power possible for reliable communication to reduce interference with other units, and to maximize the RF transmitter's lifetime
  - Short links can use much less than the maximum power level
• Encryption (key / password / pass-phrase)
  - Record the key / password / pass-phrase so you will be able to find it in the future
• Time & date
  - (Can it be set to periodically "sync" to a time server?)
• Other items written in the notes:
  - ?? = "Point-to-Point"
  (QFDM?) & CCK
  - ?? = "Band B+G"
  - Mask = "24"
  - DHCP = "disabled"

  (These may be the default settings:)
  - Mode = AP bridge
  - Band = 2.4 GHz
  - SSID = E-ZY NET.EZZ
  - Channel = "11" (2462 MHz)
  - Encryption = disabled
  - Power (OFDM/G) +20 dBm
  - Power (CCK/B) = +24 dBm
  - Attain IP Protocol = "Fixed IP"
  - IP Address = "192.168.1.1"
  - Default Gateway = "0.0.0.0"
  - DHCP Server = disabled
  - MAC Address = "00:11:7C:0C:19:2B"
  - Port Status = Connected 100 MBPS
  - Show Wireless Clients" -> "Active Wireless Client Table" ...

5-port Switch

The easiest box to set-up:

• Plug-in CAT5 cables from each related network device (wireless bridge, video encoder, network camera, computer, temperature sensor, ...)
• Plug-in its wall-wart power supply
• No programming!

Video Encoders & Network Cameras - Stardot version

The initial set-up uses a serial "null modem" cable which comes with each unit. Installation software is provided on a CD. If your computer lacks a 9-pin serial port you will need something like a USB-to-RS232 adapter. A separate computer with a serial port & CD reader could also be recruited.