# LSPIV

> Smartphone-based LSPIV for water surface velocity measurement. (iPhone/iPad app by Ryota Tsubaki.)

- Source: https://appshunter.io/ios/app/lspiv/id981387743 (this page in markdown: same URL + `.md`)
- Developer: [Ryota Tsubaki](https://appshunter.io/developer/981387742)
- Category: Education, Utilities
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 11.0 · 71 MB
- Released: 2015-04-25
- Data updated: 2026-06-24
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/lspiv/id981387743/reviews.md

## What is LSPIV?

LSPIV (large-scale particle image velocimetry) is an image-based method for measuring velocity distribution on the water surface. Applications of LSPIV have been increasing for both field and laboratory experiments as unique and powerful tools for non-intrusive velocimetry using conventional imaging devices and specialized image processing software. This app utilizes a smartphone to implement LSPIV. By innovatively combining the sensors embedded in smartphones, the images captured with them can be intrinsically and instantly ortho-rectified without making recourse to GCPs.

The app was developed under support by the River Fund in charge of the Foundation of River and Watershed Environment Management (FOREM), Japan; Grant-in-Aid for Young Scientists (B); and the Research Fund of Japan Institute of Country-ology and Engineering.

## Key features

- Large-scale particle image velocimetry
- Water surface velocity measurement
- Non-intrusive velocimetry
- Smartphone implementation
- Instant ortho-rectification
- No GCPs required


## Frequently asked questions about LSPIV

### What is LSPIV?

LSPIV stands for large-scale particle image velocimetry. It is an image-based method used to measure the velocity distribution on a water surface. This app allows you to perform LSPIV measurements using your smartphone.

### How does LSPIV work on a smartphone?

This application innovatively combines smartphone sensors to capture images that are intrinsically and instantly ortho-rectified. This means it can measure velocity without needing external ground control points.

### What kind of experiments can LSPIV be used for?

LSPIV is a powerful tool for both field and laboratory experiments. It is particularly useful for non-intrusive velocimetry of water surfaces in various hydrological and fluid dynamics studies.

### Is LSPIV suitable for beginners?

While LSPIV is a specialized technique, the app aims to simplify its implementation by leveraging smartphone capabilities. Its educational nature suggests it can be a learning tool for those new to the field.

### What devices support LSPIV?

LSPIV is available for iPhone, iPad, and iPod devices. It is designed to utilize the imaging and sensor capabilities of these Apple mobile devices.

### How often is LSPIV updated?

The latest version of LSPIV is 0.1.38, last updated on December 1, 2023. Updates typically focus on improving functionality and compatibility.

### Does LSPIV have ads?

No, LSPIV does not contain advertisements. The app is free to download and use without any ad interruptions.

### What is the age rating for LSPIV?

LSPIV has an age rating of 4+. This indicates it is suitable for users of all ages, with no content restrictions.

## Version history (last 5 releases)

### 0.1.38 — 2023-12-01

Recompiled with the latest environment to improve the stability.

### 0.1.34 — 2022-10-25

Site to access the orthophoto has changed.

### 0.1.33 — 2022-09-06

DEM downloading and handling functions had included.

### 0.1.32 — 2022-05-29

Enabling download orthophoto from internet.

### 0.1.31 — 2020-01-05

Bug fix regarding ‘send’ function.

## Apps similar to LSPIV

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Mini Secchi](https://appshunter.io/ios/app/mini-secchi/id1587116779) | — | Free | Education |
| [AeroEngineS](https://appshunter.io/ios/app/aeroengines/id1451710013) | 5.0 (1) | Free | Education |
| [CloudLabs Playing with Water](https://appshunter.io/ios/app/cloudlabs-playing-with-water/id6470240243) | — | Free | Education |
| [Kwout: English Quotes in IPA](https://appshunter.io/ios/app/kwout-english-quotes-in-ipa/id6472716548) | — | Free | Education |
| [Fun! Katakana(VPP,FamilyShare)](https://appshunter.io/ios/app/fun-katakanavppfamilyshare/id1437099711) | 4.9 (9) | $2.99 | Education |
| [MARVLS: Physics II E&M](https://appshunter.io/ios/app/marvls-physics-ii-e-and-m/id1610425856) | 4.8 (35) | Free | Education |

## More apps by Ryota Tsubaki

- [SWEapp](https://appshunter.io/ios/app/sweapp/id1530931309)

All apps by Ryota Tsubaki: https://appshunter.io/developer/981387742

## Related topics

[lspiv](https://appshunter.io/ios/topics/lspiv) · [rectify](https://appshunter.io/ios/topics/rectify) · [oyalsudokuflow](https://appshunter.io/ios/topics/oyalsudokuflow) · [oyaltaskflow](https://appshunter.io/ios/topics/oyaltaskflow)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-24.*