掩星計時最常用的視頻計時加插器

視頻計時加插器須配合有提供1PPS (pluse per second) 及 UTC 時間之輸出功能的 GPS 接收器

The bottom of the video screen has this format:

HH:MM:SS EEEE OOOO FFFFFF

where:

HH:MM:SS = Hours, Minutes, Seconds UTC time
EEEE     = latest Even field Vsync offset to UTC second (in milliseconds).
OOOO     = latest  Odd field Vsync offset to UTC second (in milliseconds).
FFFFFF   = Contiguous field count since initial GPS sync
( 6 digits allow 4.6 hours @ NTSC rate before counter rollover ).
( 6 digits allow 5.5 hours @  PAL rate before counter rollover ).

At initial GPS sync - the following data is displayed:

- Latitude and Longitude  (degrees and decimal minutes)
- Fix Status (non zero for valid FIX)
- Number of Satellites being used
- HDOP (Horizontal Dilution of Precision)
- Height of GPS aerial
- "M" for height units in metres.
- Geoidal separation (if GPS has an inbuilt table of values)
- UTC Date (DD MM YYYY)

Examples taken from KIWI OSD displayed line of info

1 07 1.5 00010.2 M 08.5

Where:  1=FIX, 07=satellites used, 1.5=HDOP, 10.2=Hgt, M=Hgt in metres, 8.5=geoidal separation

Because the geoidal separation value is displayed here, this means the GPS has a model of the difference between the WGS84 ellipsoid and Mean sea Level. So the 10.2 metre value will therefore be the height above "Mean Sea Level". So observation location has a value of 8.5 metres as the difference between MSL and the WGS84 ellipsoid.

After finished the timing run, pressing the "info" switch requests that Kiwi OSD wait for the first valid GPS fix - and then compare its internal clock to the GPS.  If they agree, a message "PREVIOUS TIMES OK" is displayed on screen. If GPS does not agree, "ERROR: USE FIELD COUNT" is displayed, alerting the user that there has been a previous GPS glitch, and to use the video field count to extract timing information.

Pressing the "info" switch after reading the above summary, gives the OSD chip a RESET, and so another timing run is started.

Kiwi OSD has informative messages describing what is happening, and whether there is a fault, eg "RS232 OR 1PPS ABSENT".

After KIWI OSD starts time stamping it requires that the camera be
operating all the time. It can cope for a short period (less than 256
seconds) if the camera is turned OFF or disconnected. However if the
video feed (from the camera) is missing for LONGER than 256 seconds,
then the UTC time will be "slow" by exact multiples of 256 seconds.

生產商回收部份有問題的 KIWI-OSD

PFD announcing a recall on some models of the KIWI-OSD.

What is wrong with the OSDs?

The design of the OSD has been proven to be very robust. However,
contrary to all experience and parts standards, the use of newer
transistors of the same type that had been used in earlier OSD models
had different pinouts that effectively meant the transistors were
backwards in the circuit. They still work as transistors, but very
poorly. The circuit design was robust enough that even with the
transistor reversed, the overall circuit function would still operate,
but with undesirably little margin against failure. Because of this
we desire to check and/or modify all units with this problem so you
can benefit from what is otherwise an excellently designed product.

How do I know if my OSD has this problem?

The symptom of this problem is the inability of the OSD, upon power
up, to recognize one of two signals that come from the GPS unit. The
screen/monitor will display "RS232 OR 1PPS ABSENT" and even though the
red LED is flashing one per second, the OSD will never begin its
timing run.

Which OSDs are affected by this condition?

Any OSD units with serial numbers between 44-1000 and 44-1100 are
known to suffer from the problem. Older units, with a serial number
starting with 41-0100 through 43-0400 may exhibit the problem but
there have been only a couple of instances of this occurring. If you
currently have placed an order for an OSD with PFD Systems and not yet
received it, you will not need to return it; the modification will
have already been applied.

What will I notice after the modifications are made?

The problem does not affect the accuracy of the OSD and once the
modification is made, it will continue to operate with the same
precision as before. The only difference you may notice is that the
red LED will flash brighter.

What should I do as an owner of an OSD?

Immediately, any owner of an OSD with a serial number between 44-1000
and 44-1100 may ship their OSD back to PDF Systems so that we can
apply the modifications to make the OSD operate at peak performance.

Owners of older OSDs, who have noticed the symptom described above can
also return their OSD as well. We urge any owner who may have
purchased an OSD in the past but who have not yet tested it to please
do so as soon as possible.

In addition, if any owners wish too, they may also return their GPS
units (only those purchased through PFD Systems) at the time they
return their OSD; we will upgrade the GPS firmware to the latest
version and also insure the configuration settings are correct.

PFD Systems will take responsibility for shipping of the units back to
you once the modifications have been made and will ship the products
back using the same level of service as we receive them. For example,
if you return the items to us Parcel Post, we will ship them back
using the same or faster service. Ship them to use using Express Mail,
and we will return them using Express Mail.

How long do I have to send my OSD back for modification?

PFD Systems will repair any OSD unit that has the problem and will pay
return shipping up to 30 June, 2009. After that time period, any
customer who has not yet returned their OSD for modification can still
do so, but will be required to pay the return shipping.

Can I make the modification myself?

The repair is not difficult and anybody who has experience assembling
and soldering electronic circuitry should be able to make the
modifications themselves, if they so desire. PFD Systems will provide
the replacement transistors and written instructions on how to make
the modifications to any of you who wish to do it yourselves. Any
additional damage caused by the user during the repair attempt will be
the responsibility of the user and may incur a repair cost if the unit
is subsequently returned to PFD Systems. Please contact PFD Systems if
you wish to do the repair yourself.

How do I send my OSD back for repair?

There is no need to contact PFD Systems prior to returning your OSD;
we do not require a RMA number. If you still have a copy of your
original invoice, please include a copy in the box along with your OSD
and write "Return for Repair" on the outside of the box. Please
include your current mailing address.

Send your OSD (and GPS if you wish) to:

PFD Systems, LLC
5900 Rudyard Dr
Bethesda, MD 20814-2234

Atten: Return for Repairs

Contact us by email at kiwiosd@...

Phone: 301-518-4326 (EST, 9am ?9pm)

How fast will PFD Systems get my OSD back tome?

Priority will be given to those OSDs with serial numbers between
44-1000 and 44-1100 since they represent the OSDs that have the
highest probability of intermittent operation. It is unknown how
quickly users will return their OSDs for repair but if you own an
older unit that doesn't exhibit the problem discussed above, you may
wish to wait and contact us in a couple of months to see what the
repair lead time is.


Disclaimer

The issues with the KIWI-OSD are a manufacturing problem and the sole
responsibility of PFD Systems, LLC and should not be considered a
reflection on the outstanding design by the inventor, Geoff Hitchcox.

To ALL users,
Please check that KIWI OSD is giving the correct time as compared to BPV or a known time source. If it is 1 second FAST, allow the GPS to run for some time (say 15 - 30 minutes), power OFF then ON the KIWI box - and then see if the Garmin GPS has corrected itself.

The 15 seconds delta , is the difference between GPS atomic time, and the UTC atomic time. It will change to "15" sometime within 12.5 minutes (time to receive the complete almanac). We don't know exactly is how "soon" does the GPS then save this "15" value to non volatile memory, for the next power cycle. The GPS receiver may not have received a "complete" almanac - so it may not SAVE anything if you turn the power OFF too soon.

KIWI OSD is that latitude and longitude coordinates are displayed in the WGS84 datum and elevations are shown in the MSL datum.

KIWI OSD 視頻計時加插器將停產

If I was asked in 2004 - is the KIWI OSD Video Time Inserter (VTI) a consumer product? I would have said of course! Just connect power and video cables, point GPS at the sky and that's it! Now after 5 years of user feedback, I know it is not that simple, there are a huge number of technical questions about using GPS technology. As the number of units sold has increased, e-mail questions have increased to a point I cannot keep up. Trying to do this in my spare and hobby time has become unsustainable.

Most e-mail is from new users asking questions, and although I have tried to keep up, I realise the technology requires a level of customer support that I simply never anticipated. It is clear that a much more complex (and thus expensive) VTI system is required to become a true consumer product that does not require such a high level of support. So after five years of production - the manufacture of KIWI OSD is soon to end, once current stock is exhausted at the USA Web Shop.

There is a need for someone to design a new "consumer" VTI, to meet the needs that have arisen since KIWI OSD was first designed - machine readable text, greater than 1 millisecond accuracy, not only "timing fault" detection - but "timing fault" correction, easy text control like font size and text positioning, and much more information provided as the GPS attempts to get a FIX.

In this respect the current KIWI OSD device is like a "beach buggy" compared to a Rolls Royce car!

However I want to reassure current users of KIWI OSD, that it still meets my original claims and specification. Some great work has been done with the little old "beach buggy", and I trust that will continue for many years to come for current users.

I can now appreciate that the next generation of VTI - is much more complex than I can design, as a hobbyist project.

However I like to think that KIWI OSD has played an important part in the development of video timing, especially the finding (from its integrity code functions) that issues involved with the "power supply and wiring" are the greatest weakness for precision video timing - rather than needing a better GPS system or receiver!

There are many many people I wish to thank for helping with the KIWI OSD project:

Vince Sempronio for USA production, Gerhard Dangl for his video precision experiments, Dave Gault and Brian Loader for local encouragement, Walt Morgan for his height studies, Scott Degenhardt and Derek Breit for pushing the envelope in all directions. Gosh so many people have advanced our use of GPS timing with all sorts of interesting experiments - and I hope this will continue for a long time.

Indeed once the dust has settled - I myself would like to do a "write up" of what I have learned over the years from the integrity code in KIWI OSD. This may help current users with more reliable data collection - and also help those designing next generation VTI systems.

Regards , Kiwi Geoff - April 2009.

KIWI OSD 已經在四月停產，由剩餘零件裝配的最後一台亦在五月七日售出。

If you have not used the GPS for some time, it could take many minutes to acquire a “fix”.

This means that you should leave the GPS attached to the KIWI, apply power to the KIWI, leave the GPS so that it can see a good portion of the sky and then wait. Wait at least 15 min. and see if you see the flashing red LED inside the KIWI.  if this does not work, Updating the firmware and settings in the GPS. After a long period of time the configuration settings can become lost. Follow the instructions in the attached document to upgrade the firmware and then try to acquire a fix using the GPS.