Islamic Astronomy Software : Digital Falak

Android is a linux-based operating system for mobile phones such as smartphones and tablet PC. Android provides an opensouce platform for developers to create their own applications for use by a variety of mobile devices.

Android already has some changes starting from android version 1.1 to the current android version 7.0. Of course with the development and improvement of android, the users were involved to develop various applications, both for personal and public purposes.

Android development is also up in the field of Islamic Astronomy. The "Digital Falak" app is one of the applications of Islamic Astronomy based on android, created by Ahmad Tholhah Ma'ruf published in the Playstore. The application is made in 2012 but in 2014 this new application is released. And in the middle of 2015 this app is officially uploaded in Playstore and can be used by many people especially for android users. Download this app in Playstore or in Digital Falak Web
.

Digital Falak Icon

Digital Falak contains several programs, there is Prayer Time, Qibla Compass, Hijri Calendar, Location Data, and Istiwak Time.

Local Prayer Time and Masehi Calendar

• Prayer Time.
Prayer Time in this application displays some data that is: the time of salat Zuhr, Asar, Magrib, Isha, Imsak, Dawn (Fajr), Thulu, and Duha. Available in 2 time, local time and istiwak time. We can also adjust the criteria and ihtiyath time in the setting menu. The prayer time in this application also has the alarm for remember us to do pray.

Istiwa Prayer Time and Hijri Calendar

• Hijri Calendar
The Hijri calendar in Digital Falak uses the two-book method of making it by using "Fathu al-Rouf al-Manan" and "Nurul anwar". Users just choose which books to use in the settings menu. there is also Masehi/public Calendar

Qibla Compass and Rashdul Qibla Calculation

• The Qiblah Compass
The Qiblah compass is quite easy to understand especially for who do not know the calculation of the Islamic Astronomy, because in it already has a Qibla Compass program, the direction shown by the compass will face the qibla, but this application has a weakness, because the base of the compass using magnetic sensor, then this application is very influential with the magnetic force that surrounds the user.
The Qibla Compass feature also requires magnetic sensors, so for mobile devices that do not have magnetic sensors can not use this feature. Instead there is also a feature Rashdul Qibla calculation, the calculation of the time where the shadow of the Sun will face the qibla.

Location Data Menu

• Location data
Location data in digital falak can be used to find the latitude, longitude, height of place, time zone and place name according to the position in GPS. This data is always updated and can also update by using the internet after the phone is connected to the internet.

This application also there is a version of the website, we will discuss in the next article.

Advantages and Disadvantages of Handheld GPS

Advantages and Disadvantages of Handheld GPS

Actually there are many types of GPS, not just handheld / portable GPS, but also GPS Navigation and GPS Smartphone. For the first of these I will discuss in advance about the GPS handheld, and now I will explain the advantages and disadvantages of GPS handheld.

Handheld GPS

GPS handhelds have a high sensitivity in receiving GPS signals and some devices are capable of receiving dual satellite systems from GPS and Glonass. We can also determine the height of place and direction in an area with satellit signal, there are also various additional sensors, for example barometric altimeter and electronic compass so that the determination of height and direction can be done without using satellite signal. This is usually an option in the settings.

The use of barometric altimeter sensors usually must first be done altitude calibration somewhere. We can also use this barometric altimeter to plot air or ambient pressure from time to time, which can help to observe changes in weather conditions.

The advantage of this GPS compass is that it is not influenced by the magnetic field and can guide the direction accurately as it is guided by signals from the satellites (not the buit-in compass sensor). This tool is certainly very helpful when measuring the direction of Qibla.

The area is remote with no phone signal and does not have internet. We recommend choosing a handheld GPS device. Maps are already stored inside, though the images are very standard, such as the appearance of road maps and soil contours, the data maps in the handheld GPS more complete, but usually sold separately (for each country) and the price is quite expensive. Maps do not need to be installed or downloaded. Because portable GPS has been installed one country map when marketed.

GPS handheld is better, more durable, waterproof and suitable for outdoor activities. Users need not be afraid of the natural conditions, because handheld GPS devices or portable GPS are designed for nature activities. Using this GPS we can find the way when through high-sensitivity wilderness, which acquires satellite signals quickly and tracks locations in challenging conditions such as trees and cliffs.

The battery can be replaced because it uses AAA batteries. One portable GPS device can last up to 25 hours. Very suitable for adventure activities in areas far from electrical energy.

But the obstacle, GPS handheld in terms of price is still quite expensive, for a GPS device ranges between Rp. 2,000,000.00 to Rp.10.000.000,00 or about $ 150 USD to $ 750 USD.

The disadvantages of all GPS, including GPS handhelds are GPS will greatly affect the geographical conditions of where we are. GPS will work well if where we are still has a wide sky. The following will be described wherever the GPS will experience a weakness in its use:

1.When someone is in the forest. With the conditions of the trees are so much then the signals that can be received will be a little maybe even no depending on the width of the forest.
2.When someone is in the water or when someone is diving. Do not expect to use this tool when diving.
3. Electronic devices that can emit electromagnetic waves may affect performance degradation rather than GPS.
4. Buildings. Not only when inside the building, being between 2 tall buildings will also cause an effect like being in a valley.
5. Signals that bounce, eg when in between high-rise buildings, can disrupt the calculation of navigation tools so that navigation tools can indicate the wrong position or not accurate.
6. Glass film car, especially metal-containing.

Prayer Times Marker

Source : http://www.algonaefree.org

One of the valid conditions of prayer/salat is in time. The times of prayer have been arranged in the Qur'an and Hadith, namely in Surat al-Isra ': 78:

أقم الصلاة لدلوك الشمس إلى غسق الليل وقرءان الفجر إن قرءان الفجر كان مشهودا

Meaning:
Establish prayer from after the sun slip until dark of night and time of the Qur'anal Fajri. The Qur'anal Fajri is actually witnessed (Surat al-Isra`: 78)

According to the commentators, in this verse is mentioned the time of prayer that is after the sun slipped, the prayers of Dhuhur and Asr. While the dark night is the prayer of Maghrib and Isha` and Qur`anal Fajri is the prayer of Shubuh .

Whereas if you want to more specifically know the theorem about the times of prayer, we can refer to the hadith of Rasululah that saheeh and qath`i. Among these are the following hadith, which means:

From Jabir bin Abdullah ra. That the Prophet was approached by Gabriel and said to him, "Rise up and do the prayer." So he did the Dhuhur prayer when the sun slipped. Then as Asr approaches and Gabriel says, "Wake up and do the prayer." So he did the Asr prayer when the length of the shadow of all things equal to the length of the object. Then the time of Maghrib approaches and Gabriel says, "Wake up and do the prayer." So he performed the Maghrib prayer when the sun sets. Then Isha time comes and Gabriel says, "Wake up and do the prayer." Then he SAW perform the Isha' prayer when syafaq (red clouds) disappears. Then when Shubuh comes and Gabriel says, "Wake up and do the prayer." So he did the Shubuh prayer when dawn broke. (Ahmad, Nasai and Tirmizy.)

1. Fajr Prayer Time (Shubuh)

Starting from the appearance of "Fajr Shadiq/True Dawn" until the rising of the sun. The dawn in Arabic is not the sun. So when mentioned dawn, it is not sunrise. Dawn is a rather bright white light that spreads on the eastern horizon that comes just before sunrise.

There are two kinds of dawn, namely "Fajr Kazib/ False Dawn" and "Fajar Shadiq/ True Dawn". "Fajr Kazib" is the dawn that "lying" as the name implies. That is, in the early hours of the morning, there is a light that extends and leads up in the middle of the sky. Shaped like a wolf's tail, then the sky becomes dark again. That is "Fajr Kazib".

While the second dawn is "Fajr Shadiq", which is the dawn of a really dawn which is a rather bright white light that spreads on the eastern horizon that appears shortly before sunrise. This dawn marks the entry of the Shubuh time.

Simulation of Shubuh Time

While the end of the Shubuh time is the rising of the Sun.

In the science of astronomy, the position of the Sun is usually denoted in an altitude value. For the beginning of dawn itself varies, some are wearing a sun-height value of -20 degrees to -15 degrees below the horizon.

Difference of Shubuh Height Value

2. Dhuhur Prayer Time

Starting from the sun is just above the head but has started to slightly leaning towards the west. The term often used is the slipping of the sun. As free translation of the word "Zawalus Syamsi". But this term is often confusing because if it says that the "sun is slipping", some people will wrinkle his forehead, "What is the slipping of the sun?".

"Zawalus Syamsi" is the time at which the position of the sun is above our heads, but a little has begun to move westward. So not right above the head. Or in Arabic terms also known as Istiwa'.

Simulation of Dhuhur Time

The end of the prayer time of Dhuhur is when entering the time of the Asr prayer.

The value of the sun's height at the time of entry Dhuhur prayer is approaching 90 degrees.

3. Asr Prayer Time

There are some differences in starting this Asr prayer :

First opinion, Asr prayer begins when the shadow of an object is equal to the height of the object plus the shadow of the object when time Dhuhur. The value of the sun's height at this position is less than 45 degrees.

Second opinion, Asr prayer starts when the shadow of an object is equal to 2x height of the object plus the shadow of the object when time Dhuhur. The value of the sun's height at this position is about 26 degrees 34 minutes

Simulation of Asr Time

The third opinion of Asr prayer is Wustha prayer is the prayer performed in the middle between Dhuhr and Maghrib prayer. The value of the sun's height at this position is more or equal to 45 degrees

But the most famous opinion is the first opinion.

4. Maghrib Prayer Time

Starting from the setting of the sun and this has become the ijma` (agreement) of the scholars. That is since the loss of all the solar spheres in the swallow of the earth. And ended up entering the time Isha'.

Simulation of Maghrib Time

The value of the sun's height at the time of Maghrib prayer is approximately -1 degrees.

5. Isha' Prayer Time

Isha' prayer begins when the emergence of red clouds in the sky.
The value of the height of the sun is also different, there is a opinion that the height of the Sun during Isha' is -18 to -15 degrees below horizon.

Simulation of Shubuh Time

And the end of the Isha' prayer is when entering the time of Shubuh prayer.

Difference of Isha Height Value