pixelcooker

How to make hillshade map from DEM using various algorithms like analytical hillshade, combined hillshade, or multi directional (mdow) hillshade.  

Another easy way to download OSM data

Nowadays, bringing maps to the field is not as complex/expensive as in the past. There are numerous software and tools that could be utilized to do that. A range of IOS/Android/Windows phone gadgets can do it using various methods either online or offline then synchronize all the fieldwork to the source data back in the office. But people usually looking for simple and cheap way no matter what is the purpose to do the fieldworks. Am I right ? so if you are one of them (like me too), I will give some insight that may  could be useful. PDF format since few years ago has been incorporated geospatial information as part of the auxiliary information stored in the file. This cool feature enabling us to save a map in PDF format (include its geospatial coordinates) and then transfer it to our phones and brings it to the field to do field check (integrated with our phones GPS Capabilities). This method sure saving us more resources instead of field online mapping (in aspect of carrier d...

I just noticed that at the recent version, ArcGIS has been implemented some sort of physical liked surface reflectance generation function in its image analysis module. The function is called apparent surface reflectance. An algorithm which takes into consideration all the iradiance related information stored in the metadata (sun azimuth angle, sun elevation angle, radiance gain/bias etc) to derive surface reflectance dataset, although it is not pure physical (because it does not consider the atmospheric condition at the acquisition date). The algorithm target the illumination condition which is theoretically should be similar between dates and wavelengths (differs in reality due to atmospheric effects, sun angle/position and sun-earth distance in every season etc) so it could be usable for color balancing and mosaicking (not sure if it will add certain degrees of accuracy in image classification). I make a guide if you want to try it by yourself

From day to day, QGIS is getting bigger and bigger. Continuous and expanded support from open source geospatial developer has made this software go beyond its initial development. More and more tools/plugins has been created and offering more flexibility and features to the software. It is fair to said that this software is now became an ideal example of successful non commercials geospatial movement. Personally I am starting to count more on this software because it is now offering some distinct tools unavailable on commercial counterparts. The keys of QGIS for me are simplicity, straightforward how to, and free to use. I am not kidding, below is an example how the simplicity means. A Tutorial about how Online Map could be deployed easily from QGIS. Using fast growing to use WebMap Frameworks like Openlayers or leaflet, a not experienced and programming literate user could make an online webmap with sophisticated looks just with some clicks. Check it out below. And last b...

Its been a while since last time I am exploring pan sharpening. Recently I am stumbled on ENVI which had  just released version 5.3 (version 5.4 will be released around summer 2016 as far I know) and it is brings some new tools in their arsenal. One of them is NNDiffuse Pan Sharpening Algorithm. ENVI has known for very long time only have 4 common image fusion/pan sharpening algorithm (PCA, Brovey, CN, and IHS/HSV) thats not quite good to maintain spectral quality of the fusion/pan sharpening result. At later version, they are adding Gram Schmidt Spectral Sharpening which is one of the most advanced pan sharpening algorithm to date and making them equal with ERDAS (Ehlers/wavelet fusion) and PCI (UNB Fusion) as the most advanced Pan Sharpening Software. Now they are adding NNDiffuse which is the latest algorithm developed by Weihua Sun et al, NNDiffuse utilizing regression approach combined with spatial frequency extraction to generate pan sharpened dataset which not only mainta...

Another platform to download Landsat-8 Data No login and registration needs, more intuitive than Glovis/EarthExplorer

Another tutorial, how to convert your ArcGIS MXD into offline maps consumed for Android/IOS Smartphones

A friend just asked me to help her dealing with some ArcGIS 10.2 MXDs while she currently only has access to ArcGIS 10.1, and yes her ArcMap wouldnt open the MXDs. Version differences sure could be real pain in the ass if you are working in multi environment map making. So make sure you are using newest version available in the market (no need to waiting for the crack because "the good guy" ESRI is so kind to give us, literally, 2 months trial, but, actually it is a lifetime trial if you are evil enough to figure out the way). The conversion method is pretty easy and straightforward (even elementary student can do it). But, it will be at different level if you got a bunch of MXDs stored in a bunch of folders, and you need to convert it all. How will you do it? doing it one by one is a disaster man.You will eventually losing precious time while you could use it to go date with some girls out there.  Fortunately, we got phyton which proven to be life saver at difficult ...

ALOS adalah satelit penginderaan jauh milik jepang yang diluncurkan tahun 2006 dan berhenti beroperasi pada tahun 2011. Satelit ini membawa tiga sensor pencitraan, yaitu AVNIR-2 (beroperasi pada mode multispektral 4 saluran Blue-Green-Red-NIR dengan resolusi spasial 10 meter), PRISM (beroperasi pada mode pankromatik secara triple stereo dengan resolusi 2.5 meter) dan PALSAR (sensor SAR dual polarisasi). Citra ALOS banyak digunakan di Indonesia selain karena cakupan wilayahnya yang luas harganya juga relatif murah (3-5 juta rupiah per scene). Citra ALOS didistribusikan dalam dua format, geotiff (*.tif) dan CEOS format. Untuk format geotiff kebanyakan software bisa membuka data ini tanpa masalah, namun untuk format CEOS sampai saat ini hanya software pengolahan citra digital penginderaan jauh yang baru bisa membukanya (ENVI, ERDAS, PCI dan mungkin juga yang lain). ESRI Jepang beberapa waktu yang lalu telah merilis sebuah tool dalam bentuk toolbox agar format CEOS dapat dibuka di software...

Para pengguna ArcGIS Server tentu sudah sangat paham dengan yang namanya REST Map Services. REST (representation state transfer) Map services merupakan format distribusi data spasial via Web yang digunakan ESRI untuk mendukung diseminasi data spasial via web. Map services menggunakan REST protocol dapat digenerate dan dihosting menggunakan perangkat lunak ArcGIS server. Bentuk umum REST mirip dengan OGC WMS, dimana client akan me-request data spasial kepada server yang akan di-return oleh server dalam bentuk gambar peta dan beberapa atribut yang diperlukan. Layanan REST dapat diakses dengan memasukkan URL tertentu disertai serangkaian tag query untuk memanggil data. Katalog REST URL dapat diakses dari REST Service directory. Contoh REST Service directory yang dapat diakses publik milik Kementerian/Lembaga/Instansi antara lain : 1. Kementerian PU 2. BIG 3. INA-SDI 4. BNPB 5. Kementerian Pertanian 6. Kementerian Kehutanan 7. Kementerian Perhubungan,, 8. dan masih banyak lagi ins...

Di tepi pantai kok GPS-nya nilai ketinggiannya bukan nol ? mending bro yang saya alami malah nilai ketinggiannya negatif!, hmmmmm pasti GPSnya rusak, mari kita "lembiru" (lempar ganti baru)...... :) GNSS/GPS receiver secara default menggunakan acuan ketinggian (datum) berdasarkan ellipsoid WGS-84 (datum koordinat global), sehingga nilai ketinggian/elevasi yang diperoleh merupakan ketinggian diatas ellipsoid (HAE : Height Above Ellipsoid). Jika GPS yang kita gunakan menggunakan setting ini, maka tidak heran apabila ketika kita survei di pinggir pantai, ketinggiannya tidak nol atau malah mungkin negatif. Hal ini dikarenakan lokasi yang kita survei menurut WGS-84 ketinggiannya bukan nol. Ketinggian yang mendasarkan pada nilai nol diatas garis pantai rata rata disebut dengan MSL (Mean Sea Level). Kenapa bisa ada dua acuan ketinggian yang berbeda?. Hal ini dikarenakan bentuk bumi tidak sepenuhnya bulat, karena itu ketinggian nol di pantai ancol jakarta sejatinya tidak sama de...

Saya teringat sewaktu pertama kali praktikum GIS. Software yang pertama kali saya pakai adalah PC-ArcInfo (Software GIS berbasis DOS dari tahun 80-an).. If you remember you were using ArcInfo... congrats there is no mistake anymore that you are OLD!!!!!!. Software yang menyebalkan memang, its all command based and I spent a whole day just to place those four annoying tick marks from digitizer tablet to the computer monitor. I even promise my self to not to take the GIS practices too serious. I hate this stupid digitizing thing. walaupun esok harinya mata saya berbinar - binar karena software yang dipakai adalah ArcView GIS (alhamdulillah its GUI based) and.. you know the rest is history..wkwkwkw, I still practicing GIS today.   ArcInfo memang menyebalkan, semua orang tahu itu, tapi yang mungkin tidak banyak diketahui orang (apalagi anak anak jaman sekarang). ArcInfo adalah software GIS terbaik dalam artian dia mempunyai format data spesifik yang bisa dimanipulasi tanpa lim...

Melanjutkan postingan sebelumnya tentang orthorektifikasi foto udara, pada postingan kali ini saya akan coba uraikan bagaimana cara orthorektifikasi foto udara menggunakan software ENVI. Untuk informasi tambahan, selain di ENVI, software lain yang bisa mendukung orthorektifikasi foto udara antara lain PCI geomatica, ERDAS IMAGINE, SOCET SET, ILWIS, dan GRASS, dan juga mungkin software software pengolahan citra yang lain. Sebelumnya, monggo silahkan di download file KML berikut ini ( link ), kemudian coba tampilkan di google earth. silahkan diamati di daerah bergunung dimana disitu nampak efek relief displacement pada foto sangat besar. File KML ini dihasilkan dari koreksi geometrik menggunakan toolbar georeferencing ArcGIS. Dari hasil tersebut nampak bahwa georeferencing saja tidak cukup untuk mengkoreksi relief displacement. Anda bisa koreksi ulang dengan menambahkan GCP, meningkatkan orde transformasi polynomial-nya ke orde 2 dan yang lebih tinggi, tapi tetap tidak akan diperoleh ...

phyton scripting di ArcGIS, mungkin tidak banyak orang yang mengeksplor ArcGIS sampai kesini, tapi berani jamin, anda akan kecanduan memakainya bila sudah memahami fungsionalitas dan manfaatnya. Contohnya misalnya seperti ini. "Saya mempunyai beberapa data raster dalam sebuah geodatabase, saya akan memotong raster (clip) tersebut menggunakan data raster dari geodatabase lain (bisa juga dari geodatabase yang sama). Solusinya ada 4. Pertama, proses clipping manual?? well, it is long and damn boring . kedua, proses clipping otomatis pake batch processing??? apa anda tahan membuat tabel batch untuk 250 raster yang akan anda potong??. ketiga, Bikin model builder ???, ugh I want to clip rasters right here and right now, not to drawing ballons, bubbles, and arrows. dan ini yang keempat, Phyton Script.  nah!.yang ini nih baru oke!, cuman ngetik beberapa baris kode and voila, all rasters clipped!!!." Oke, jadi gini tutorial penggunaan phyton script 1.  Buka Phyton Window di ...