We've got an android ínside our ride this morning

Lately we've been minding some few renovations inside our ride. When we have just purchased a new sound system inside it, we thought of actually having something to view upon. A mobile theater system so to speak. We usually place our notebook in the dashboard then let our kids watch from the backseat, but too bad, it doesn't have some solid state drive so we're afraid it might get damaged because of some vibrations. Then we just decided to buy an APad, a smaller one and something that would fit rightly on top of our dashboard.

We grabbed a unit of an aPad (MID APad M701 7.0 Inch Touch Screen Android Tablet PC )
because its cheap and its running in Android OS. Android is opensource and there's an android app market installed in it where we can shop for cools apps for free. And for it's purpose as an in-house movie player for our car, it would serve very much beyond our need. I can do my e-book reading (as a colored version of a Kindle), plants vs zombies, social networking, bible reading and many many more while stuck in a traffic jam on my way to the office.

Basic tech specs:





CPU Processor Speed:

633MHZ DSP VIA8505 FOR M706 /M710

2GB (Expandable up to 16GB)



Memory Slot:



0.3M Pixels digital camera

Color Display:

7 inch TFT LCD with Resistance Touch Screen



Battery Type:

rechargeable Polymer battery.

Battery Capacity:

3000mAh / 2.5hours continuous usage 72hours standby





G Sensor:


I/O Ports:

T-flash, 3.5mm headphone, In-built microphone.

Wireless Network:

WiFi 80211b/g / LAN


OS Android 2.05


Google Browser










Google Map

It also works on Globe Tattoo, Smart Bro and Sun Wireless broadband for 3G internet. Plus lots of free software packages available such as GoogleMap, Facebook, Bible, PvZ, Youtube, Document to Go, Google Chrome lite browser, Skype and many many more. Plus free downloadable apps in some android market. I am now currently fishing apps (educational games ) for my kids at .

Some cool educational apps my husband spotted at androidzoom:
- Kid mode: Kids games + videos
- Pearson Education
- Chicken Preschool 

My little Cassy and David would surely love playing with these games on and off board.

My aPad comes with a leather casing too, extra protection for better portability.

Will post more about new functionalities and adventures with this Android dude in the days to come!

The whereabouts of our car repair and maintenance

We gave our ride, a Daewoo GTE Racer, some holiday treat this Christmas season.

Since it's a second hand auto, we had it's airconditioning system fixed and we bought a set of interior car mats on it. Next up, is its periodic car maintenance by changing the brake pads, spark plugs, fuel and oil filters, change engine and gear oil and replaced the wiper blades. Finally we've had the auto tint replaced, bought a new car stereo and speaker.

Here's a map of our whereabouts regarding our car maintenance.

View CAR SOLUTIONS in a larger map

Periodic Car Maintenance at CAPITOL AUTO SUPPLY

Auto Tint installation

Car Stereo, Speaker and Power Antenna Installation
Maintaining a car was quite expensive but really the comfort it brings us especially when we have our kids on board is really worth the spend.


This Family Badly Wants a Blackberry Curve 3G for Another Weekend/Holiday Adventure...

It's Christmas time and I'll take a break on writing some geeky stuff and do spend this rare chance to post about my wonderful family. It was my 4th Christmas away from my mom and dad, and also my 4th being a mom to two wonderful kids and a very loving husband. And as I may say I'm so blessed.

We do take shots of the very precious moments we do spend together. Be it a simple ice cream eat out, birthdays or our Anniversary, we do keep and treasure every moment were blessed to share together.

We say we're camera whores and we badly need a Blackberry Curve 3G to do the task for us. My phone is almost retiring now, and it's a good thing TechPinas has their TechPinas Gadget Bonanza # 1 where I am crossing my fingers on getting a new phone. You know moms, being "kuripot" and all, just of course to save even a little will count much to hardly make both ends meet.

Me and my husband Perci are always out for work on weekdays and even on Saturdays too for Perci... that's why we make it a point to spend our Sundays (and holidays as well!) with them ..go to church, eat out, stroll and play at the park,...that means so much to them, and for us too. Me and Perci always wish we will always have time for bonding moments like this..'coz we know it's not the quantity but the quality of time we have for them that really counts...

For this year 2010, here are the simple yet very memorable adventures we've shared... Captioned specially for TechPinas Gadget Bonanza # 1.

A family with a Blackberry that goes to church together stays together...
The 32GB storage space of Blackberry will record many more moments like this... 
Next year Cassy will turn 5... and next year the shots will be from our very own Blackberry...
Hope we'll get it free from TechPinas...
We'll fit ourselves inside this small inflattable pool just to have a Blackberry curve 3G!
Smile like crazy with a Blackberry!
Geo-tagging photos and posting them directly to my Facebook
and Twitter account is easy with my Blackberry curve 3G...
More joyrides like this with a GPS on our car, powered by a Blackberry Curve 3G
Yes we are camera whores...  and we badly need a Blackberry Curve 3G
for more bonding moment shots like this...
PHOTO TAKEN ON OUR 100th month anniversary...  

Hope to have more of these kind of adventures next year and the years to come.


Deciphering FX Driver Weird Phonetics

Everytime I ride an FX on the way to school or the office, I am having this trouble understanding the terms that the FX drivers use when they talk over their radio (walkie talkie). It feels like I'm being alienated or whatever out of place in their conversation with another driver over their walkie-talkie. Quite strange, even wondered why are they having such codes? What if they are leading us to some odd place... "Money Market, Tango, Oscar Kilo Oscar Kilo!" WTF?  hahahah... 

Here are some of their frequently used terms,  just so we may be well informed.

oscar kilo - OK
Tango Sierra - Tandang Sora
double mama - MMDA
Money Market - Terminal/End of the line, lugar na pinagkakakitaan (NOVALICHES BAYAN)
Tango - Tao
Uniform Tusok - U-Turn
Sierra Mike - SM North
Sierra Bravo - SB Road
Spaghetti pababa - clover leaf sa balintawak
White lady - north cemetery, bagabag cemetery
Legaspi - mayon
tamagochi -pulis
yellow boys - SB traffic officer
Kilo Papa - Kingspoint subdivision
Alambre - shortcutan nila
Evacom- Ever Gotesco Commonwealth

I'm excited to know more of these codes in the future. Just for FUN!

I'm adding another one in the list, care of my friend Jefferson Pingol.

Itik- mga estudyanteng  lumalabas galing sa school.

More phonetics to come (^_^).

These phonetics must have originated from the original police codes. Check out this link .


Creating Entity-relationship Diagrams (E-R Diagrams)

Last semester for my introductory GIS class, part of a laboratory exercise is on creating E-R Diagrams which for me is a simple graph of the relationships between different objects within an interface. In programming, it is much like the UML (Unified Modeling Language) class diagrams that we are making before proceeding to the actual coding.

E-R diagram 
A data model, which is a high level description of the available data, is needed in storing relevant information in a database. In designing databases, there should be a conceptual and the physical phase. The creation of E-R (entity-relationship) diagrams belong to the conceptual phase. The E-R diagram serves as the blueprint before creating a database.

There are things such as entity sets within an E-R Diagram
1. Entity – person, place, object, event, concept. 
representation in the E-R diagram - table in the database
shape in the E-R diagram -  RECTANGLE 

2. Entity sets – collection of similar entities (same as “class” in object - oriented languages)

3. Attribute – property / characteristic of an entity
representation in the E-R diagram - fields in a table
shape in the E-R diagram -   OVAL 

4. Relationship – the link between entities 
representation in the E-R diagram - primary key-foreign key equivalence in related tables
shape in the E-R diagram -   diamond or writeup in the relationship line

Sample E-R Diagrams that I have made
Case1: Finding the best location for a landslide - flooding evacuation site using GIS

Case2: Developing a GIS that will be used to organize and display real property information

For creating simple E-R and UML diagrams above , I use a free and light weight java application called UMLET. UMLet is very easy to use, simple drag-and-drop of some preset icons and you can also create templates out of your UMLs and you can easily export your final diagram in pdf,jpeg and other supported formats and UMLet is open source. 


Free online color matching tool for your maps

 Maps do convey relevant information to a target audience.  Maps, apart from being informative, should be artistic too. Cartography is art. I mean you cannot just combine your violets with the greens or blues with it. A right combination of RGB or CMYK swatches will make it appear more pleasing and more eye-catching. And if you have 12 classes in a thematic map, you wouldn't want it to be randomly picked as if making some sort of lantern decoration for the Christmas season. Color coordination really is the name of the game.

My husband who's into creative design is my one true critic when it comes to color combination. He would just peek into my final map for a project or laboratory exercise and then tell me to use this color or another color theme instead of my initial picks. He was such a relief when I am finishing my maps when he's at home. But when  he's not around, hard part comes.

Anyways, I have stumbled upon this book last semester and found it really useful. Great tips and illustration for beginner to intermediate level cartographer.
GIS Cartography: A Guide to Effective Map Design

Also there are free online matching tools that will surely be of big help to us.

Color brewer which was made specifically for cartographic purposes is a great tool for picking just the right color sets for our thematic maps. Color schemes for the color blind option is really great. It also considers the type of data present in your map and the map context. The best feature is an embedded score card which indicates if your output is colorblind friendly, color printing friendly, photocopy friendly and/or LCD friendly.

Another color matching tool is Color Blender. It's not actually focused on cartography but more of color scheme guide for just about anything such as logo design. web site or print design. It already has a gallery of blends from which you can choose from. The option for downloading or sending blend  along with its active color function works just as great.


Hope to enjoy mix and matching with such array of color schemes in my upcoming maps.


Free PDF to WORD options

Latest versions of Microsoft Office and OpenOffice are already capable of  saving your  documents from doc, docx or odt to  pdf format. The reverse is quite unusual.

There are trial versions of pdf to word converter with their limitations of course. PDF2Word can only be used 100 times and allows the first 5 pages only to be converted to .doc format. Fonts change and the layout was a bit different after conversion. 

The most useful for me is using the OpenOffice PDF Import Extension. If you have OpenOffice installed in your pc, just double click the downloaded extension and an installation dialog will guide you through. 

The pdf opens in OpenOfficeDraw and lets you do basic editing of text and images in the document.

You can save the edited file as another pdf or export as an image file or in html format. 

It's free and it's open source so let's see more developments of this extension on OpenOffice. It would be nicer if pdf files can be opened in Writer and saved in odf.

Free Class Schedule Notification on your Mobile Phone using Google Calendar

At long last, after one long week, I am finally enrolled for the 2nd sem AY 2010-2011. The entire enrollment experience has been really tedious and cumbersome because of usual queues, considering the enrollment is already online and automated.

Anyways, I am now officially enrolled, so I would just have to tidy things up in my calendar. I set-up my Google Calendar to send me notifications of my scheduled class for the night on my mobile phone. The notifications are free so why not!It pays to be organized for some time anyways.

Here's my schedule for this sem. And some other events/notifications on my Google Calendar.

I created a test event for today and scheduled it to arrive 10 minutes before the time. Voila! I received a text message from Google saying:

Reminder:test @ Thu Nov 11 12:20pm-1:50pm in PIVS (melanie's google calendar).

Memorizing class schedule and room assignments have been quite a mess during my undergrad years. I used to print it and paste it on my notebook way back then. But it would be better if I'd receive some electronic notification, for this case text message from my friend Google.

Well here's how I did it.

1. Set-up your mobile number on your Google Calendar. Its on the Google Calendar>Settings>Calendar Settings>Mobile Set up.
2. Save settings then validate it later using the code sent on your mobile phone.
3. Create a new calendar for your subjects this sem.

4. On your newly created calendar, encode your subjects, building and room number, and the time of course using the Create event option in the calendar.

5. Specify if it is twice or once a week by checking the repeat button below the event title text box.

5. Set-up the SMS notification on the subject/event. During my undergrad years, when my subjects are overloaded, we are allowed to go out of class 15 minutes before the time, that's the time allowance for walking or taking an IKOT/TOKI ride for our next class. So I guess a notification of maybe 20 minutes will do.

6. Save settings and you're done.

Hoping for an exciting, challenging and productive semester ahead of us!


Image Registration and Georeferencing in ENVI (Cavite, Philippines)

Georeferencing and Registration Methodology
The following steps were undertaken for the rectification or georeferencing of the image:

1. I have created a subset of the province of Cavite from the Landsat ETM+image that I have downloaded from GLCF . A topographic map of the equivalent subset has been obtained with the following basemap information.

Fig. 1: Basemap information

Scale 1: 50000..
Sheet name Cavite, Philippines
Sheet number 3163 II

2.  A scanned 1:50000 topographic map of Cavite appears below.
Fig. 2a: 1:50000 Topographic map of Cavite
3.  An Image-to-map registration was performed using the coordinates on the boundary of the map as ground control points. A total of 10 points are obtained with a total RMSE of 0.396853.

4.  An Image-to-Image registration was later performed, yielding 9 GCPs with a total RMS error of 0.970929. The Landsat ETM+ image that I have obtained has already undergone the Level 1G correction hence the warping from the originally downloaded image to the warped image was observed.
Fig. 3a: Distribution of ground control points within the Landsat ETM+ image of Cavite

Fig. 3b: Georeferenced image of Cavite, Philippines

Some Discussions

On topographic maps vs. satellite images
Topographic maps are already orthorectified hence it can be used to measure distances between two points. Name of features are also available on a topographic map. Depending on the level of correction contained on the satellite image, it may or may not be georeferenced or orthorectified. Satellite images show terrain of ground features. Moreover, satellite images are captured at different wavelength bands in the electromagnetic spectrum hence analysis and interpretation can be performed on more than three dimensions. Depending on the field of application or query, one can switch on different color composite diplays on the different bands contained in the satellite images to facilitate interpretation. Scanned topographic maps on the other hand utilizes only the visual RGB bands. Topographic maps are available on different scales depending on the area needed for interpretation. Satellite images, depending on the capabilities of the sensor, are available in different radiometric, spectral and spatial resolutions. One satellite image covers a very large area unlike topographic maps which contains relatively smaller areas hence producing finer details and information on features in it.

On the use of topographic maps for geometric rectification
Use of topographic maps poses some potential problems when used for geometric rectification. Depending on the date of execution of the topographic survey used for the map, information contained in it whether man-made or natural fatures may have already been altered through time. This is crucial for the identification and location of ground control points. Medium used for printing the topographic map is also a factor to be considered. Different materials expand and contract as the temperature of its environment changes. This expansion or contraction causes significant distortions on the features printed in the map. Paper when folded or crampled also causes geometric distortion of the features on the map. When scanned, printer resolution and other abberations caused by the glass on the scanner may also cause geometric distortion on the basemap. Lastly, when ground control points (GCP) are chosen, the interpolation of the corresponding coordinates of the GCPs may also be subjective depending on the discretion of the observer which may cause significant difference on the inetrpolated versus the true ground coordinates of the GCP.

On coordinate transformation
The RMS error measures the errors between the destination control points and the transformed locations of the source control points. A root mean square error is calculated for each transformation performed and indicates how good the derived transformation is. The transformation is derived using least squares, so more GCPs can be given than are necessary. Specifying a minimum of three GCPs are required to produce a transformation that results in an RMS error. The formula for the calculation of RMSE appears below.

To come up with an acceptable degree of spatial accuracy, RMSE should not be greater than 1.

Depending on the method of transformation, the number of minimum number of coordinates needed for transformation may vary. For 2-dimensional conformal coordinate transformation, which preserves the orthogonality of the coordiante systems, a minimum of 2 control points for scale change, rotation and translation are needed for transformation. On the other hand, 2D-Affine transformation which preserves the parallelism of parallel lines, 6 parameters are needed to facilitate transformation hence a minimum of three control points to produce 6 equations with 6 unknowns.

Computation for the parameters of each transformation method.

Using the following formula for conformal and affine transformation, a JAVA program was produced to compute the parameters for transformation.
    Fig 4a: Working equations for the formulation of matrices for 2D Conformal and Affine Transformations
The input file contains the coordinates from the GCP text file of Image-to-Image registration in ENVI. The output file produces the parameters for transformation.

The following table are the input coordinates in solving for the parameters for transformation.

Fig. 4b : Base and warp image coordinates as ground control points
Base Image Warp image
x y x y
2197 467 4288 3435.75
2101 915.25 4255.75 3581.5
1406.25 1293 4027 3709
757.5 1964.5 3806.25 3933.5
377 256.5 3705.16 3376.46
2831.5 1920 4491.25 3914
2869.25 638 4504.5 3487.25
1804 1168.25 4156.94 3667.62
1797.75 797.75 4157.56 3545.68

The following tables contain the resultant parameters for 2D Affine and and 2D Conformal Coordinate Transformation respectively.

Fig. 4c : Parameters for 2D Affine transformation
Parameter Value
a0 3579.92167
a1 0.32503
a2 -0.00779
b0 3291.26455
b1 -0.00444
b2 0.32919

Fig. 4d : Parameters for 2D Conformal transformation
Parameter Value
a1 0.32605
a2 -0.00021
a3 3569.72659
a4 3286.96612

On different transformation and resampling methods in ENVI
Upon application of the three different transformation methods , the resulting images are warped differently. The figure below compares the amount of warp present in the image after each transformation using different resampling methods.

    Fig. 5: Amounts of warping in the Cavite satellite image using RST, 2nd and 3rd order polynomial transformation
    After geometric corrections and translations, resampling is being performed to produce a better estimate of the DN values for individual pixels. In the nearest neighbor algorithm, the transformed pixel takes the value of the closest pixel in the pre-shifted array. In the bilinear interpolation, the average of the DN values of 4 surrounding pixels is used while cubic convolution averages the 16 closest input pixels.
    Images resampled using cubic convolution produces the sharpest image.


Hold-out validation (HOV) uses another set of GCPs for the same image dataset to verify the spatial accuracy of the georeferenced image.

    Fig. 6a: Hold-out Validation using a new set of ground control points of the Cavite Landsat ETM+ Image
Shown above are the relative loaction and ditribution of the new set of ground control points. Nine (9) GCPs which yield a total RMS error of 0.448321.

Leave-one-out Cross-Validation (LOOCV) - Cross-validation uses all of the data to estimate the trend and autocorrelation models. It removes each data location, one at a time, and predicts the associated data value.

Fig.6b : Sample Leave-one-out Cross Validation
The figure above shows how LOOCV works. After choosing the GCPs and minimizing the total RMSE to less than 1, the Image to Image GCP list was arranged such that the point with the largest RMS error appears on top of the list. This point was turned off and effectively the total RMS error of the GCPs lowered from 0.970929 to 0.818812. If we hit the predict button in the Ground Control Points Selection dialog,the cross hair on the zoom window will center on the point that will give the lowest total RMS based on the correlation of points of the image.

On Level 1G correction of Landsat images 
Upon rectification, distortions caused by platform and surface geometric characteristics can't be easily distingushed since the image obtained has already undergone level1G correction which is a format created by NASA to indicate imagery that is basically ready to use .L1G" is indicative of "Level 1G", meaning the data has been processed to level 1 and is radiometrically and geometrically corrected. 

On Image-to-image vs. Image-to-map registration
An image to image registration is a lot easier than image to map registration. You just have to scan the topographic map and georeference it using the graticule values given on the borders of the map. Bias on the map-scaling interpolation is removed because once you georeference the image, the coordinates on the pixel of the desired GCP within the georeferenced image is readily available. The drawback however is on the manner of scanning the topographic map. The resolution of the scanner that will produce the output topo map as well as the current state of topo map upon scanning greatly affects the quality of data one can extract in the scanned map. Folds and cramples or obliterations on the map produces significant distortions on the coordiantes derived from the map.