Archive for the ‘Telemetry’ Category

Raspberry Pi As a Cheap Home Surveillance System

Sunday, January 19th, 2014

CCTV

Home surveillance systems are incredibly expensive, but if you’re looking for more of a DIY approach, Instructables user Scavix shows off how to build your own small-scale system for about $120 using a Raspberry Pi.

Scavix’s system uses a Raspberry Pi, the Raspberry Pi camera module, some housing for that camera, and a few other smaller pieces. After some set up, the end result is a home security system that can detect motion, broadcast a live stream, and more. It’s a surprisingly powerful system all things considered and it’s cheap enough that you can set up a few of them if you like.

Source: Instructables

$20 GPS/GLONASS/Beidou Receiver

Sunday, January 19th, 2014

GPS Module

Sticking a GPS module in a project has been a common occurrence for a while now, whether it be for a reverse geocache or for a drone telemetry system. These GPS modules are expensive, though, and they only listen in on GPS satellites – not the Russian GLONASS satellites or the Chinese Beidou satellites. NavSpark has the capability to listen to all these positioning systems, all while being an Arduino-compatible board that costs about $20.

Inside the NavSpark is a 32-bit microcontroller core (no, not ARM. LEON) with 1 MB of Flash 212kB of RAM, and a whole lot of horsepower. Tacked onto this core is a GPS unit that’s capable of listening in on GPS, GPS and GLONASS, or GPS and Beidou signals.

On paper, it’s an extremely impressive board for any application that needs any sort of global positioning and a powerful microcontroller. There’s also the option of using two of these boards and active antennas to capture carrier phase information, bringing the accuracy of this setup down to a few centimeters. Very cool, indeed.

Source: Hack A Day

Israeli Drone Pilots Made Their Life-and-Death Choices Over Gaza, and how?

Saturday, November 24th, 2012

A Heron drone at the Palmahim air base in Israel in December of 2011. Photo: AP/Dan Balilty

The latest round of fighting between Israel and Hamas has settled into an uneasy ceasefire. But that won’t stop Israel’s drones from filling the skies over Gaza. In this 2009 story, written during the final days of the last Israel-Hamas  conflict, we took a look at how one drone pilot grappled with the moral choices that came with remotely spying, and ordering death, from above.

Life or Death choices will never been easier with judgement done through small screen. how these guys, manage doing these task properly or most importantly humanly. Guess, wired have this story covered here. Come on, take a look.

Courtesy: Wired.com

 

GPS Units Disable Themselves If They Go Faster Than 1,200 MPH

Saturday, August 13th, 2011

This is somehow a legacy border, but anyone out there have busted this fact? – GPS units disable themselves if they go faster than 1,200 mph and if they go above 60,000 feet…

GPS module

In GPS technology, the phrasing “COCOM Limits” is also used to refer to a limit placed to GPS tracking devices that should disable tracking when the device realizes itself to be moving faster than 1,000 knots (1,900 km/h; 1,200 mph) at an altitude higher than 60,000 feet (18,000 m).This was intended to avoid the use of GPS in intercontinental ballistic missile-like applications.

Some manufacturers apply this limit literally (disable when both limits are reached), other manufacturers disable tracking when a single limit is reached.

This limit is a frequent obstacle encountered, if not discussed, among hobbyists seeking to make high altitude balloons and of course would be a problem for homemade space programs.

courtesy: wikipedia

Hacking Home Automation Systems Through Power Lines

Saturday, August 13th, 2011



 

X10-Jammer.png

Quoted from Hackaday.com

As home automation becomes more and more popular, hackers and security experts alike are turning their attention to these systems, to see just how (in)secure they are.

This week at DefCon, a pair of researchers demonstrated just how vulnerable home automation systems can be. Carrying out their research independently, [Kennedy] and [Rob Simon] came to the same conclusion – that manufacturers of this immature technology have barely spent any time or resources properly securing their wares.

The researchers built tools that focus on the X10 line of home automation products, but they also looked at ZWave, another commonly used protocol for home automation communications. They found that ZWare-based devices encrypted their conversations, but that the initial key exchange was done in the open, allowing any interested 3rd party to intercept the keys and decrypt the communications.

While you might initially assume that attacks are limited to the power lines within a single house, [Kennedy] says that the signals leak well beyond the confines of your home, and that he was able to intercept communications from 15 distinct systems in his neighborhood without leaving his house.

Can’t imagine how someone disturbing your private time while you’re enjoying your hot bath? think again. have a nice weekend.

Courtesy: Hackaday, Wired

How GPS Bends Time

Saturday, July 16th, 2011

Equation section, WIRED magazine:

GPS-time.png

Einstein knew what he was talking about with that relativity stuff. For proof, just look at your GPS. The global positioning system relies on 24 satellites that transmit time-stamped information on where they are. Your GPS unit registers the exact time at which it receives that information from each satellite and then calculates how long it took for the individual signals to arrive. By multiplying the elapsed time by the speed of light, it can figure out how far it is from each satellite, compare those distances, and calculate its own position.

For accuracy to within a few meters, the satellites’ atomic clocks have to be extremely precise—plus or minus 10 nanoseconds. Here’s where things get weird: Those amazingly accurate clocks never seem to run quite right. One second as measured on the satellite never matches a second as measured on Earth—just as Einstein predicted.

According to Einstein’s special theory of relativity, a clock that’s traveling fast will appear to run slowly from the perspective of someone standing still. Satellites move at about 9,000 mph—enough to make their onboard clocks slow down by 8 microseconds per day from the perspective of a GPS gadget and totally screw up the location data. To counter this effect, the GPS system adjusts the time it gets from the satellites by using the equation here. (Don’t even get us started on the impact of general relativity.)

 

courtesy: wired.com

A GPS without GPS

Monday, July 11th, 2011

gsmlocalizerWow, that sounds weird. It’s actually a mini GSM-based localizer without any GPS devices attached. It’s an old device with the cheaper SimCom module SIM900.  Here is a complete working GSM localizator which is pretty cheap and small too.

As introduction, this system allows localization without directly using GPS technology; we are able to locate the desired object fairly precisely by using database availability together with the geographic position of the cells themselves. In some country the cell coordinates are not publicly known (i.e. in Italy). If so, where do we find such data? Through Google Maps… Google has been able to store billions of data regarding the location of its clients’ cell phones. But how does GSM localization work? The radio mobile network is made up of a number of adjacent radio cells, each of which is characterized by an identifier consisting of four data: a progressive number (Cell ID), a code related to the area in which that given cell is (LAC, or Local Area Code), the code of national network to which the cell belongs (MCC, an acronym for  Mobile Country Code), and finally the company code (MNC, or Mobile Network Code), which obviously identifies the phone company itself. For this reason, once a cell name and coordinates are known, and considering the maximum distance allowed between this cell and a phone  before the phone connects to a new cell, it is possible to find out, approximately, the most distant position of the phone itself. For example, if the maximum distance has been determined to be one mile, the cell phone can be within a one-mile radius. It can be deduced that the more cells are found in a given area, the more precisely one can determine where the phone is located (up to 200-350 feet). The idea of employing only a GSM device to build a remote localization system occurred to us when we realized that Google Maps Mobile, which had been conceived to allow smartphones equipped with a GPS receiver to use Google for satellite navigation, was extended to all cell phones, as long as they were able to support GPRS or UMTS data.  Naturally, this method allows but for a rough estimate: determining the precise position of the cell phone hinges on data regarding the coverage of a given cell which can only be provided by the Google server.

DataCell

The circuit

Compared to traditional localizers based on GPS, this device presents many advantages, primarily because it is lighter and less bulky, has a cost lesser and greater autonomy to exercise. This means that about one battery lithium ion, such as 1 Ah, our tracker can be in operation for several days (it all depends on the number of SMS that have to do). A locator based on cellular network may answare more immediately: the GPS receiver may take several minutes to determine its position. Our tracker works battery and thus can be brought on by people who may have the need to ask help or be tracked, but also placed on board motor vehicles (without installation) or simply introduced in goods in transit. To avoid unnecessarily draining the battery, the localizator provides its position via SMS, on requesto with a simple phone call. Among the functions implemented there is the SOS: By pressing the button the localizator sends a text message asking for help, containing the coordinates of position, the sending can be done to a maximum of eight thelephone numbers. When queried or with the autoreport function, sends an SMS with the localization.To know the location of remote device must send an SMS request cell is connected and sends a request (via GPRS) to Google’s site, the latter responds with the coordinates and the figure for the precision. Everything happens in seconds.

0908_Schema

Well, you can get hell of these stuff from link provided afterward. Design files and the firmware are included. A fun stuff to experiment with at your disposal. Mini GSM localizer without GPS at open-electronics.org.

All images are courtesy of open-electronics.org

Japan setting out to get its own GPS off the ground

Sunday, July 3rd, 2011

japan-gps.jpgHow’s your Sunday? ah-ha, here some GPS-related article for your weekend technological feed, have a nice weekend.

The Japanese government – with the the assistance of private firms – is ramping up research on a Japanese version of the Global Positioning System in a bid to turn satellite-based technologies into a key export, the Nikkei reports. As far as we know,  it’s already runs. But turning it into an export – is really a good idea to me.

Plans are afoot to conduct joint research and development on this – nine firms and two organisations are slated to participate in a study group to be formed by the Ministry of Economy, Trade and Industry at the end of the month, with an aim to come up with new services in five years, the report says.

The venture will include companies such as NEC and Mitsubishi Electric Corp, which develop satellites or ground facilities, as well as those with a broad range of businesses, including transport systems, logistics and machinery.Having launched a quasi-zenith positioning satellite last September, the addition of two or three more satellites will enable an around-the-clock service, though specific plans for the second satellite haven’t been drawn up yet.

The Japanese satellite system is designed to supplement the GPS currently operated by the US, and is meant to cover the region, including that of Southeast Asia and Australia.A domestic GPS would yield many benefits beyond just making and launching satellites – with a projection that the overall market will grow from around four trillion yen in 2008 to roughly 10 trillion yen in 2013, a wide range of infrastructure-related fields will stand to grow as well.

Courtesy: paultan

Related:  Quasi-Zenith Satellite System, QZSS

A Brief Description of SCADA System Signals

Sunday, June 19th, 2011

It has been a while, I left this site without any updates. So, here I present a basic of a SCADA system signal. It’s basic and have to describe it a way earlier but, left out with an assumption every SCADA engineer should have known it. Anyway, as a general reading, this topic should be one of important information for public readers.

basic circuit of instrument signal tappingThe most common current signal standard in modern use is the 4 to 20 milliamp (4-20 mA) loop, with 4 milliamps representing 0 percent of measurement, 20 milliamps representing 100 percent, 12 milliamps representing 50 percent, and so on. The use of a 4 mA reading to indicate zero is known as “live zero.” This helps to distinguish a zero reading from a “dead signal” or non-functioning equipment. The range of readings possible for a properly functioning system then is only 16 mA (20 mA – 4 mA). This 16 mA range is known as the “live signal.” The actual reading being recorded in mA is called the “process variable.” The PV indicates a percentage of a particular measurement being monitored. The table below shows the relationship between various PVs and their corresponding percentages.

signal comparison tableA convenient feature of the 4-20 mA standard is the ease in converting these signals to 1-5 volt indicating instruments, as the table on the left shows. A simple 250-ohm precision resistor connected in series with the circuit will produce arange of readings from 1 volt of drop at 4 milliamps to 5 volts of drop at 20 milliamps. The current loop scale of 4-20 milliamps has not always been the standard for currentinstruments. In the past, 10-50 milliamp signals were used more frequently. That standard has since become obsolete. The main reason for the eventual supremacy of the 4-20 milliamp loop was safety. Lower circuit voltages and lower current levels (compared to 10-50 mA systems) mean less chance for electrical shock injuries and/or the generation of sparks capable of igniting flammable environments in certain industrial applications.

An Overview of  SCADA Signal Calculations

Definition of terms

Dead signal: A reading from a non-functioning system that can be mistaken for a measurement.
Live signal:
The range of possible process variables. In a 4 – 20 mA system, any signal below 4 mA or above 20 mA indicates malfunctioning equipment. The range of useable signals is between 4 & 20 mA. Therefore, the live signal = 16 mA.
Live zero:
A reading other than zero used to indicate zero so that a zero reading can be distinguished from a dead signal. In 4 – 20 mA systems, the live zero = 4 mA.
PV:
Process variable. The signal reading, in mA, that represents a percentage of a particular measurement.

One of the more common uses for SCADA systems is the monitoring of storage levels. Formulas for making these calculations include:

mA to feet conversion

So, given a SWH of 30 ft, and board reading of 14.67 mA, the water level would be calculated as follows:

water level calculation

Kindly, do enjoy to use or share this information. Have a nice day.

Reference: Water Opcert School

How Earthquake and Tsunami Warning Systems Work

Sunday, March 13th, 2011

seismic flowchart

How Earthquake and Tsunami Warning Systems? — Earthquake and tsunami warning systems both monitor the same thing: seismic waves. Seismic data takes the Earth’s pulse directly, so when the earth shakes, we get immediate feedback. If all goes well, we have enough time to run.
Lots of organizations watch for earth movement. The U.S.’s Advanced National Seismic System (ANSS), for instance, runs 95 stations across North America. When there’s an earthquake, ANSS sends out a signal in real time, which alerts government agencies and emergency response personnel.
Earthquakes on land are serious business, to be sure, but responding to them is fairly straightforward: Direct the appropriate resources to the place where the alarm bell rang the loudest. But when earthquakes cause tsunamis, an international effort is usually required. Think about it: An earthquake under the sea doesn’t just cause a killer wave directly above it. Landmasses shift, water is displaced, and, depending on several other factors, it could end up anywhere.
Seismic waves travel 100 times faster than ocean waves, so you have to take the Earth’s movement into account to figure out when the wall of water will hit land. To understand just how important it is to use seismic data to get people safe, you only need to look back to the magnitude-9.0 Indonesian quake of 2004. The Indian Ocean had no early warning system in place, and the tsunami triggered by the earthquake killed 200,000 people in eleven countries—including 30,000 people in Sri Lanka, 1000 miles away from the epicenter. Information just didn’t get to the people who needed it fast enough.
But today, when the 8.9 hit, the Japan Meteorological Agency issued a major tsunami warning within three minutes of the event. Six minutes after that, Islands in the South pacific, Hawaii and Russia were told to watch their shores. The collaborating systems are a part of the Intergovernmental Oceanographic Commission run by UNESCO, which organizes international disaster response.
Japan is hyperaware of its shaky ground. The country withstands some thousand tremors a year, and they’ve got 180 seismographs and 600 seismic intensity meters constantly tuned to what’s going on in the underworld. They also have around 30 sea level gauges operated by the coast guard and around 80 operated by the JMA that work in chorus to provide feedback to a Data Processing and Communication system. The sensors take a reading, upload it to a central processing system using old fashioned wires and/or satellite uplink, and that central system sends updates to the government, police, coast guard, telephone companies, and the media. Sea level gauges also report disturbances in real time and help organizations model trajectory and size of the oncoming waves.
And then there are more specialized tools. The NOAA, for instance, has a handful of tsunami detection buoys that help rule out false alarms and give monitoring agencies a better idea of what they’re in for-or what their not. NOAA’s Deep Ocean Assessment and Reporting of Tsunami system—which goes by the slick moniker ‘DART’—is made up of an anchored sea floor bottom pressure recorder and accompanying fiberglass and foam buoy on the surface. The recorder on the ocean floor, which takes a note of temperature and pressure every 15 seconds, sends data via an acoustic link to the surface buoy. The buoy then sends information by satellite to Tsunami warning centers.
How does the information get to you? Warning systems coordinate with the media. That’s how you got the information on your front page. To get even faster info, in many places you can sign up for text alerts if something disastrous is happening-or will happen, in the case of a tsunami-in your area.

courtesy: gizmodo