Getting an auto rickshaw at your doorstep!

This blog has discussed this issue earlier and has suggested a few related project ideas: 

http://www.newstudentresearch.blogspot.in/2013/03/virtual-cars-for-everyone.html
http://www.newstudentresearch.blogspot.in/2009/01/potential-impact-of-cellular-technology.html

The purpose of this posting today is to suggest a simple project you can implement in a day or two, excluding a few days of learning time if that is necessary in your case. I will describe it in the Indian context mentioning “autos”, that is auto rickshaws. Obviously it will work for a variety of vehicles such as cabs, and even the inter-city buses that wait for passengers!

The suggestion is this: Create a website at which auto drivers can register, giving their name, cell phone number and vehicle number. Later, they should be able to send a short message to a server, giving the location at which they are waiting for passengers. They should mention a clear landmark, for example: Lal bagh.

The site will display over the Web a table giving driver’s phone number and location giving city name as well. Any one requiring an auto could do a web search mentioning something like this:

Site:www.getauto.in   Lal bagh

and select one of the displayed phone numbers. The rest of the work of contacting the driver and giving him the pickup address is left to the user. Later on one can add additional facilities like sending the user an SMS/email giving driver name and site registration number (SRN). In the rare event it is required, the police can use the SRN, contact the site and get driver’s license number, etc.

Remember – only the simplest ideas work first! You can of course write an App, but wait.Should you expect the auto driver to have 2G or 3G connectivity? Or should you try to build a system with an SMS interface? I suggest that you first focus on using a 2G/3G connection. Postpone your market expansion program for the present.

Srinivasan Ramani

Putting a radio beacon on an asteroid

The asteroid named "the Beast" is approximately a thousand feet wide, and is big enough to release 2,000 Megatons of energy if it collides with the earth. That could wipe out a whole metropolitan city. Fortunately, it did not do that during its latest pass on June 8, 2014. It is not expected to come dangerously close any time soon. Officially, its name is 2014 HQ124. For further information, here are a couple of URLs. 

http://www.jpl.nasa.gov/news/news.php?release=2014-178

http://www.dailymail.co.uk/sciencetech/article-2651228/Beware-Beast-1-000-foot-wide-asteroid-come-million-miles-Earth-Sunday.html

This time, the Beast passed within 750,000 miles of the earth. Isn’t time that a technology is developed to attach a transponder to such asteroids so that they can be tracked accurately as far away as a hundred million miles? A good solution would be to have the transponder orbit the asteroid in a fairly tight orbit. It would be necessary for the transponder to orient itself in space and point an antenna towards the earth for long distance communication. Would the development of such an orbiting transponder be a good project for university students?

Why a transponder? Why not a simple beacon? A transponder allows fairly accurate distance measurement; but that may not be essential. A beacon that transmits at fixed intervals may be sufficient to let good tracking of the orbit to be done. I think that a major challenge is in designing a system to locate the direction of the earth and to keep a directional antenna pointed at it. Are there powerful signals sent out 24/7 from the earth that can be utilized to sense the direction of the earth from the asteroid? The Wikipedia gives a list of radio time signal stations around the world, including a 2000 KW transmitter working at 162 KHz in France and a 2.5 KW transmitter working at 20 MHz in the US. Obviously, the 20 MHz transmitter is attractive because one can design a highly directional antenna to work with it, but how do you design a simple mechanism to locate it in the first place and to re-acquire the signal if it is lost for a short time for some reason? One option seems to be to use a Sun seeker and to use rotation with an axis perpendicular to the plane of the solar orbit to acquire the earth signal. Assuming that the asteroid's orbit and that of the earth are not highly inclined to each other, the directional antenna sweeping the plane of the orbit can locate the earth. The satellite can then de-spin itself and point the antenna to wards the earth. The system should be able to work with a few different radio sources spread over the world.  

Another challenge would be in increasing the design life of the transponder to make it worth the effort of launching it. Yet another challenge would be in having the transponder adjust its orbit over the years, so that it does not crash, or get pulled away by the earth or the moon during its future passes. Both challenges would require that one does not depend upon rocket fuel being carried on board, because it would run out rather soon. Considering the very low gravitational force involved, ionic propulsion is a possibility for making necessary changes to the orbit. Or, who knows, may be a good solution is to launch a one ton tank of fuel, with a 20 Kg transponder tacked on outside!

Srinivasan Ramani